Newsgroups: rec.photo
From: acs@csri.toronto.edu (Alvin Chia-Hua Shih)
Subject: Canon EOS FAQ
Summary: Very few changes from last time.
Keywords: Canon EOS AF Camera Bodies
Date: 5 Jan 93 09:45:45 GMT

Well, it looks like the rec.photo site has fallen down and can't get
up.  So, I'm posting an interim copy of the FAQ.  I've been *way* busy
over the holidays, so I haven't made any substantial changes.  Don't
bother reading it if you've seen V1.5.  (I hope to implement something
that will show which items have changed, but the numbers aren't stable
anyway...) Please save questions and comments for *Version 1.8* (which
I hope to have out by the end of February).

I don't have a lot of EOS 5, A2E, etc. info yet, but hopefully the Elan
and 10s info will carry over until such time that I can assemble some
specific info.  For now, just think of the A2E as a nice cross between
then Elan flash system with the 10s multi-segment metering and
multi-sensor AF (extended to 5 zones instead of 3).

ACS

CONTENTS:

Canon EOS FAQ, Version 1.65 Alpha:
1.  Nomenclature:
1.1.  Acronyms:
1.2.  Model Number Equivalencies:
2.  Flash:
2.1.  Other than the 430 EZ, what are my options?
2.2.  What's the difference between "meter" and "feet" versions of the  430
EZ?
2.3.  Why doesn't the AF illuminator on my flash work with my 10S?
2.4.  On the Elan, can I get red eye reduction with slow sync flash?
2.5.  On the Elan, can I use red eye reduction with 2nd curtain sync?
2.6.  On the Elan, how do I get a smaller aperture with more DOF  using  my
flash?
2.7.  Can I get an off-camera flash cord for my 630/RT?
2.8.  Why doesn't the A-TTL out-of-range warning work on my 10S/Elan?
2.9.  How do I change the fill-flash ratio?
2.10.  Why doesn't Canon use distance information for flash exposure calcu-
lations?
2.11.  How can I find out more about using flash with my EOS?
3.  Lenses:
3.1.  Can I use my FD-mount lenses on EOS bodies?
3.2.  Can I use EF-mount lenses on FD-mount bodies?
3.3.  Why have the focusing motor in the lens?
3.4.  Doesn't the motor in the lens make the lenses more expensive?
3.5.  Manual focusing with USM lenses?
3.6.  Can small animals hear USM lenses?
3.7.  Is there any way to focus a USM lens without annoying the cat?
3.8.  Canon lenses look too expen$ive.  What about third-party?
3.9.  Why didn't Canon think of using distance information (like some other
nameless company :-)?
3.10.  So what are affordable Canon lenses worth getting?
3.11.  My lens cap is too loose.  What can I do?
3.12.  Can I use the Canon EF teleconverters on my EF lens?
3.13.  My lens pulls its filter threads inside the lens barrel  and/or  the
filter threads turn during focusing.  How can I use a circular polarizer?
3.14.  How can I use a rubber lens hood if my front filter threads retract?
3.15.  What are TS-E lenses?
3.16.  Why are TS-E lenses so expensive?
3.17.  Why should I use an EOS-1 with TS-E lenses?
4.  Focusing:
4.1.  Manually focusing doesn't give me the AF confirmation light.   What's
wrong?
4.2.  Why is the manual focus throw so short?
4.3.  So what techniques are there for precise manual focus on an AF lens?
5.  Viewfinder:
5.1.  I wear glasses.  Can't see all of viewfinder and/or  the  information
display.  What can I do?
5.2.  Why can't I focus on both the viewfinder image and/or the information
display?
5.3.  What's the eyepiece cover for?
6.  Miscellany:
6.1.  Can I get warranty service, even if I didn't buy it in this country?
6.2.  How Do I Leave the Film Leader Out?
6.3.  Where do I Get a Film Leader Retrieval Tool?
6.4.  How do I get exposures longer than 30 seconds?
6.5.  What's a Technical Back E?
6.6.  How do I use bulb mode without shaking my camera?
6.7.  Where is this socket on the 630, 650 or RT?
6.8.  How do I get long exposures on the Rebel/EOS 1000?
6.9.  I need a manual for my Canon camera.  How do I get one?
6.10.  How can I shoot more than 36 exposures on an EOS-1?
6.11.  What is Canon's phone number?
7.  Bodies:
7.1.  What's an EOS RT?:
7.2.  Is the EOS Rebel/1000 any good?
7.3.  What's an EF-M?  The Rebel is only $30 more!
7.4.  Can I use IR film in the EOS Elan/100?
7.5.  What is in those bar codes?
8.  Batteries:
8.1.  Why don't I get as much life out of my batteries as my  manual  would
have me believe?
8.2.  I just got my camera and have been  fooling  around  with  it.   I've
already lost two bars on the battery check, and I haven't even run any film
through it!  What's happening?
8.3.  What are the "hard numbers" on battery use?
8.4.  I'm down to one flashing bar.  Do I have to throw the battery away?
8.5.  If I let the battery die, will I lose my film count or  custom  func-
tion settings?
8.6.  The 430EZ eats batteries too quickly.  How can I get more flashes out
of my 430EZ?
8.7.  What if I want a LOT more flashes and/or faster recycling (because of
fast action and/or cold weather)?
8.8.  What about non-Canon high-voltage packs?
8.9.  High voltage packs look too expensive.  What are my options?
8.10.  I don't have a high-voltage jack on my flash.  What are my options?
8.11.  What is a low-voltage pack?



Canon EOS FAQ, Version 1.65 Alpha:

This is an attempt to address the common questions pertaining to the  Canon
EOS camera system.  It makes no attempt to address any questions pertaining
to the FD-mount  cameras.   Only  recently  have  I  scrounged  enough  EOS
A2/A2E/5  information to say anything meaningful.  Alas, I haven't had time
to incorporate much.  Please wait for Version 1.8 or so.

Permission to redistribute this FAQ is granted so long as  it  is  done  so
without  charge  of any kind, that no changes are made, and that it is dis-
tributed in its ENTIRETY, including this BANNER and the ATTRIBUTIONS!

This information is derived from postings on the net as well  as  brochures
and  books.   The  EOS net.personalities who have been particularly helpful
include:

        Robert M. Atkins
        Mike Coren
        Thomas Greve
        Robert Groom
        Al Goldis
        Ralph Jenson
        Stephen Page
        Paul Repacholi
        Barry Sherman
        Peter Shizgal
        Benson Wen
        and many others.


Special thanks to Jim Cathey who got me hooked on the  EOS  system  in  the
first place and answered many of the questions that now appear here.

The information presented is as accurate as possible, but if you blow some-
thing  up,  I  ain't  takin'  no  fall!  (I'm soooo tired of disclaimers in
legalese!  :-)

Corrections and additions are always welcome (even  spelling  and  grammar!
:-).  I can be reached at:  acs@csri.utoronto.ca.


1.  Nomenclature:

1.1.  Acronyms:

EOS:
     Electro-Optical System.  Canon's designation for the line  of  cameras
     which  control  their lenses strictly electronically.  That is to say,
     aperture and focus are controlled by motors in the lens itself, rather
     than in the camera body.

EF:
     Electro-Focus.  The designation for lenses that  are  compatible  with
     EOS bodies.

AFD:
     Arc-Form Drive.  The electro-mechanical assembly used to focus some of
     Canon's  older  EF lenses.  It contains a small DC motor and transmis-
     sion housed in an assembly shaped like an  arc  to  avoid  interfering
     with  the  light  path  in  the lens.  These motors are audible to the
     human ear, in contrast to USM-driven lenses.

EMD:
     Electro-Magnetic Diaphragm.  The electro-mechanical assembly found  in
     every  EF  lens  that  is used to control the aperture.  This assembly
     includes a small motor to avoid the necessity for a mechanical control
     linkage to the camera body.

USM:
     Ultrasonic Motor.  A type of motor used in more recent EF lenses.   It
     is  inaudible  to  the  human ear, but it has been reported to disturb
     cats.  There are two variants: ring-shaped  and  "micro".   The  ring-
     shaped  motor  is  found in Canon's higher-end USM lenses and is ring-
     shaped to avoid interference with the  light  path.   It  boasts  high
     torque and does not require any form of transmission.  The "Micro-USM"
     is cylindrical, much cheaper to  manufacture,  and  probably  requires
     some form of transmission.

A-TTL:
     "Advanced" TTL flash uses a 1/20th strength  preflash  (IR  in  direct
     mode,  visible  light  in  bounce mode) to determine how much light is
     added to a scene by the flash and how far down  the  aperture  can  be
     stopped  while still providing adequate exposure with the flash.  This
     aperture is compared with the aperture that would be selected by  nor-
     mal  Program  mode  (within  the  constraints of the body's flash sync
     speed and lens' widest available aperture).  The smaller  of  the  two
     apertures  is  selected.   When the shutter button is fully depressed,
     the flash fires and is quenched using the TTL flash circuitry.

     For a more detailed description, ask Canon for a "Speedlite  Reference
     Guide".

CF:
     Custom Function.  These are actually user-set parameters  rather  than
     functions.   :-)   They allow the user to set various handling charac-
     teristics of the camera.

QCD:
     Quick Control Dial.  The dial found at the back of the  EOS  1,  Elan,
     and  A2 camera bodies.  It is used to control exposure compensation or
     aperture without the need to press a "shift" key in  conjunction  with
     the main input dial.


1.2.  Model Number Equivalencies:

Canon, like many other Japanese  camera  companies,  uses  different  model
numbers  for  the same camera bodies, depending on the country in which the
camera is to be sold.  The following equivalence chart is provided by  Mike
Coren:

North America          International
___________________________________________
1                      1
10s                    10
Elan                   100
630                    600
Rebel                  1000
Rebel S                1000 F
Rebel II               1000 N
Rebel S II             1000 FN
A2E                    5



2.  Flash:

Canon refers to flashes  as  "Speedlites".   Their  nomenclature  typically
specifies  the guide number in metres, followed by "E" to indicate EOS com-
patability.  An additional "Z" indicates that the head can be "Zoomed" (see
below).


2.1.  Other than the 430 EZ, what are my options?

The 430EZ is currently Canon's top-of-the-line  flash  for  the  EOS  line.
Third  party  flashes  are  quite a bit cheaper, but typically lack certain
features.  Consult the table below for comparisons.   Please  mail  me  any
additions or corrections (I'd especially like to hear about Metz).

______________________________________________________________________________
|Manufacturer     |   Canon   |   Canon   |   Canon   |   Canon   |   Canon   |
|Model            |   430EZ   |   420EZ   |   300EZ   |   200E    |   160E    |
|Price            |   $230    |   $200    |    $95    |    $50    |    $30    |
|GN               |  83-145   |  83-140   |  73-100   |   65/45   |    52     |
|Zoom Head        |    A/M    |    A/M    |     A     |     N     |     N     |
|Coverage         |   24-80   |   24-80   |   28-70   |  35/28 %  |    35     |
|Bounce           |     Y     |     Y     |     N     |     N     |     N     |
|Swivel           |     Y     |     Y     |     N     |     N     |     N     |
|A-TTL            |     Y     |     Y     |     Y     |     N     |     N     |
|TTL              |     Y     |     Y     |     Y     |     Y     |     Y     |
|2nd Curtain Sync |     Y     |     Y     |     N     |     N     |     N     |
|AF Assist        |     Y     |     Y     |     Y     |     N     |     N     |
|Var. Fill        |     Y     |     N     |     N     |     N     |     N     |
|Var. Output      |     Y     |     Y     |     N     |     N     |     N     |
|Ext. Power       |     Y     |     N     |     N     |     N     |     N     |
|Batteries        |  4 x AA   |  4 x AA   |  4 x AA   |  2 x AA   |   2CR5    |
|_________________|___________|___________|___________|___________|___________|
__________________________________________________________________
|Manufacturer     |  Vivitar  |  Vivitar  |  Vivitar  |  Sunpak   |
|Model            |   628AF   |   636AF   |   728AF   |   433AF   |
|Price            |    $60    |    $95    |    $55    |    $75    |
|GN               |    80     |    120    |    92     |    120    |
|Zoom Head        |     N     |    ???    |    ???    |     N     |
|Coverage         |    ???    |  28-85?   |  28-85?   |    35     |
|Bounce           |     N     |     Y     |     Y     |     Y     |
|Swivel           |     N     |     Y     |    N?     |     Y     |
|A-TTL            |     N     |     N     |     N     |     N     |
|TTL              |     Y     |     Y     |     Y     |     Y     |
|2nd Curtain Sync |    ???    |    ???    |    ???    |     N     |
|AF Assist        |     N     |     N     |     N     |     N     |
|Var. Fill        |     N     |     N     |     N     |     N     |
|Var. Output      |     N     |     Y     |     Y     |     N     |
|Ext. Power       |     N     |     N     |     N     |     Y     |
|Batteries        |    ???    |    ???    |    ???    |  4 x AA   |
|_________________|___________|___________|___________|___________|



Legend:

Price:
     Approximate selling price in U.S. dollars.

GN:
     Guide number in feet.  For zoom flash heads, a range is given to indi-
     cate the guide number when covering minimum and maximum focal lengths.

Zoom Head:

     A -  can automatically zoom to cover the focal length setting  of  the
          lens

     M -  can be manually zoomed


Coverage:
     Gives an indication the minumum focal length that can be fully covered
     by the flash, and also the range of the zoom head.

A-TTL:
     Indicates whether or not the flash supports A-TTL mode.

Var. Fill:
     Indicates whether the automatic fill flash ratio can be adjusted.  The
     normal fill flash ratio is 1:1.  There are numerous reasons to want to
     adjust it (which are beyond the scope  of  this  manufacturer-specific
     FAQ.)

Var. Output:
     Indicates whether or not the flash supports variable flash  output  in
     manual mode.


2.2.  What's the difference between "meter" and "feet" versions of the  430
EZ?

The "meter" version is functionally identical to the "feet" version  except
that  the distances displayed on the LCD panel for flash-coupling ranges in
manual mode are given in metric units rather than imperial.   In  the  USA,
these units are probably grey market.


2.3.  Why doesn't the AF illuminator on my flash work with my 10S?

The 10S has 3 AF sensors, the centre cross-sensor detecting both horizontal
and vertical detail, and the outer two vertical sensors detecting only hor-
izontal detail.  Canon AF sensors on earlier bodies were horizontal sensors
which detected vertical detail.  As such, the current flash units provide a
pattern of vertical bars which are not useful to the outer  AF  sensors  on
the 10S.  In addition, the pattern is not wide enough for all 3 AF sensors.
So, the 10S disables the flash's AF illuminator in favour of the one  built
into the body.

This is no great loss since the flash-integral AF illuminator is  not  much
more  powerful  than  the body-integral AF illuminator (if at all).  The AF
illuminator on the flash was mainly provided for the the earlier EOS bodies
which did not have built-in AF illuminators.


2.4.  On the Elan, can I get red eye reduction with slow sync flash?

Yes, but only if you are using 1st curtain sync (CF2=0).


2.5.  On the Elan, can I use red eye reduction with 2nd curtain sync?

Although the Elan manual doesn't explicitly forbid it, the answer is  still
"no".

Normally, the red eye reduction  illuminator  stays  activated  until  just
before  the  main  flash.   With  2nd  curtain sync (CF2=1), the shutter is
already open when the flash fires.  Having the red eye reduction  illumina-
tor on just before the main flash fires would affect the exposure.  In par-
ticular, there would probably be some kind of "ghosting effect" that  would
be difficult to balance with the main exposure.

Why Canon doesn't have the red eye reduction illuminator deactivate  before
the  first curtain opens is subject to speculation.  There are two conceiv-
able reasons for Canon disabling it:

1)   Any significant amount of delay between the extinguishing of the  red-
     eye  reduction  lamp and the firing of the flash may allow the eyes to
     readjust to the darkness.  This, of course, would give red eye anyway,
     and needlessly consume battery power at the same time.

2)   Too much of delay in taking the exposure would  allow  human  subjects
     time  to "squinch up" their faces in response to the red eye reduction
     lamp (making for rather unattractive people pictures).

The easiest thing to do is stick with 1st curtain sync.  If you *must* have
2nd  curtain  sync  and find red eye unbearable, buy a hot shoe flash which
supports 2nd curtain sync, like the 420/430EZ.  By having  the  flash  head
farther off the lens axis, red eye is reduced without the need for any kind
red eye illumination.


2.6.  On the Elan, how do I get a smaller aperture with more DOF  using  my
flash?

You have to use Manual mode.  You set the aperture (for DOF), you  set  the
shutter (to avoid camera shake) and TTL/OTF metering handles the rest.  The
usual suggested shutter speed is 1/60th.

NOTE!  Watch your guide number *carefully*.   The  28-80/3.5-5.6  is  slow!
Thus,  stopping down too far will cause the flash to underexpose.  The Elan
has a guide number of 12-17m (depending on flash zoom).

Remember that the guide number formula is: range = GN/aperture.  So f/8  is
definitely a long shot.

Also note that with smaller apertures, more flash output is required.   You
will go through (expensive) lithium batteries more quickly.

If you need more kick, you'll need a shoe-mounted flash.


2.7.  Can I get an off-camera flash cord for my 630/RT?

The Canon off-camera shoe cord designed to support A-TTL does NOT  work  on
the 630 nor RT (I have confirmed this with Canon Canada, despite rumours to
the contrary).  The flash works perfectly in the  hot  shoe,  and  the  TTL
modes have been reported to work correctly with the cord.

The general consensus is that Canon increased to CPU  clock  speed  to  get
faster AF, but in the process didn't upgrade the drivers on the shoe circu-
itry.  This, combined with the capacitance of  the  cord,  results  in  the
serial  data  degrading  too  severely for the body to communicate with the
flash.  Attempting to use the flash cord with A-TTL on a 630/RT  will  usu-
ally  result in the minimum aperture, fastest X-sync speed, and 2nd curtain
sync being set.  The TTL modes still work probably because they use trigger
lines,  and  not  the  serial  data  line.   There have been reports of the
drivers being overloaded to the point of being damaged, so one should check
flash functions when buying a used 630...

The way to use off-camera flash with the 630 is to use TTL Manual mode.  If
you  wish the 430EZ to be your main source of illumination and your subject
is close, set Tv=125, Av=8.  This will give good depth of field.  To expose
more  for  ambient light, use shutter priority with Tv=60.  In general, use
the guide number calculations leaving some margin for error,  and  let  TTL
flash metering do the rest.

Finally, the shoe cord documentation indicates RFI emission  problems  with
certain bodies.


Peter Shizgal reports that he has had success with a custom-made cord  from
England.   It is similar to the Canon off-camera cord in that it is coiled,
and has a tripod socket for the flash shoe, but the difference is  that  it
works  with  the  630!   His  comments  from  email and a previous post are
included below:

From:   Peter Shizgal <SHIZGAL@CSBN1.Concordia.CA>
Subject: Re: CANON off camera flash cord. Operation with 630. Any info?
X-Organization: Concordia University, Montreal, Quebec

I have been using Leung's one-piece cord with the EOS 630 for quite some time
now (about 1 year?), with very good results.  The device is well-built, from
Canon parts, and has withstood considerable knocking around in my camera bag.
A strain relief is included and appears to work well.  When connected to the
EOS 630 by Leung's cord, the 430EZ flash behaves as if it were mounted directly
on the hot shoe.  The cord is expensive, but in my shooting, it has been worth
the cost.

The following is my original posting about the cord:

******************************************************************************

From: shizgal@vax2.concordia.ca (PETER SHIZGAL)
Newsgroups: rec.photo
Subject: Canon EOS off-camera shoe cord
Date: 21 Nov 1991 21:52 -0500
Distribution: world

There have been several recent postings concerning the use of Canon's
off-camera shoe cord with EOS-series cameras.  Introduction of this cord lowers
the cost of attaching a single Speedlite to an EOS camera and provides better
functionality than the older multi-piece setup when only a single flash is
used.  The older setup can accommodate multiple flashes, but at the cost of
sacrificing the preflash, A-TTL mode, flash head autozoom, infrared AF
auxiliary light, and TTL mode distance readout.  These functions share a data
line that must be disconnected because of the possibility of contradictory
preflash distance readings from multiple flashes.

I have contacted a senior technical rep at Canon USA regarding the use of the
one-piece off-camera shoe cord and have confirmed that it will NOT work with
the EOS 630 and RT.  The cord works fine with the EOS-1, 620, and 650.  The
cord will also work with the EOS 10, Elan, and Rebel, but exceeds the FCC noise
regulations.

I own an EOS 630 and a 430EZ Speedlite, so this wasn't good news for me.
Fortunately, a fellow netter, Paul Sandy, recommended that I contact David S.H.
Leung, a Canon (and Contax-Yashica) specialist in Ilford, England, regarding a
custom-built cord.  Using Canon parts, Leung manufactures a cord that allows
the 430 EZ Speedlite to be connected off-camera to the EOS 630 while
maintaining full functionality.  (Leung's rep won't comment on whether on not
the FCC noise spec is exceeded.)  I have tested this one-piece cord, and as far
as I can determine, it behaves as advertised.  Simply put, the Speedlite
appears to function as if it were mounted on-camera.

I was pleased by the service provided by Leung's shop.  I contacted them by FAX
and received a prompt and informative reply.  They somehow managed to ship the
off-camera cord from England to Canada in less than a week.

Now for the not-so-good news:  The price is 68.00 sterling (about $120 US)
including tax and shipping.  I would imagine that a low volume of production
and the use of Canon parts contribute to the high price, which is more than
twice the cost of the Canon off-camera shoe cord (~ $50 US via mail order).
However, the Canon off-camera shoe cord won't work with the EOS 630 and RT, so
this comparison is moot for users of these cameras.  The Canon setup that will
work consists of the TTL Hot Shoe Adapter II, an off-camera shoe adapter, and a
connecting cord.  These items total about $95 US via mail order, not including
shipping.  Moreover, Leung's cord offers full functionality whereas the
three-piece Canon setup does not.  Finally, it is possible that Leung would
agree to work with user-supplied components and would lower his price
accordingly.

The person who answered my inquiries concerning Leung's cord is Alan Burch.  He
can be reached care of

                David S.H. Leung
                33 Goodmayes Road
                Ilford, Essex IG3 9UN
                England

                Tel. 81 590 3268
                     81 599 6657
                FAX: 81 590 0293

The shop is open every day except Thursday and Sunday.

==============================================================================
| Peter Shizgal                        | CSBN, Concordia University          |
| Internet: Shizgal@CSBN1.Concordia.CA | Montreal, Quebec, Canada            |
==============================================================================

******************************************************************************

Exchange rates have changed since I posted this, and the price may have changed
as well.

- Peter



2.8.  Why doesn't the A-TTL out-of-range warning work on my 10S/Elan?

Canon claims they disabled the function on  the  newer  bodies  because  it
wasn't  accurate  beyond  25 ft.  For objects of low reflectance, the flash
would signal a false alarm.  (However, I still think it's useful for making
sure  the  bounce angle is correct...  Sigh...)  Estimate flash range using
the guide number formula, and account for *at  least*  one  stop  of  light
being lost on bounce flash.


2.9.  How do I change the fill-flash ratio?

In the EOS system, only the 430EZ has controls to support variable fill vs.
ambient  light  ratios.   For flashes without such controls, quite a lot of
fiddling is required.  [Quick note.  The A2/E flash  exposure  compensation
does affect shoe-mounted flashes.  I'll update this later.  ACS]

The "Speedlite Reference Guide" suggests that flash  exposure  be  adjusted
using  the  exposure  compensation  control  (or changing the film speed on
bodies without exposure compensation).  However, in programme modes,  since
the  exposure  compensation  control  affects  *both*  flash exposure *and*
ambient exposure, manual exposure mode must be used to get proper  exposure
for the background.  This, of course, means that the A-TTL programme cannot
be used.

For example, if one wanted to have 1 stop less flash exposure  relative  to
ambient  exposure, have the flash on TTL mode, and the body on manual mode.
On the body, set the exposure compensation to -1 (or double the film speed)
to  reduce  the  amount of flash exposure by 1 stop.  For the ambient expo-
sure, set the shutter speed and aperture manually to  give  one  stop  more
exposure  than manual metering recommends (since exposure compensation will
affect the manual *metering*).

Most indoor shooting does not involve *fill* flash.   The  background  will
usually be underexposed.  However, one can still decide to reduce the flash
output and have the negatives "printed up", giving somewhat better  balance
between  the  subject  and background.  In this case, the shutter speed and
aperture do not change too often.  The aperture is wide open  or  close  to
wide open, and the shutter speed is 1/60 (slowest speed that should be hand
held).  So just set these manually, and set the  exposure  compensation  to
-1.  Make sure to check the settigns if lighting conditions change.


2.10.  Why doesn't Canon use distance information for flash exposure calcu-
lations?

Distance info is only useful so  that  the  camera  can  apply  the  "guide
number" formula: f-stop = GN/distance.  This is only a rough approximation.
Off-The-Film (OTF) metering measures the true exposure of the  film,  which
is much more accurate than the guide number calculations.

In ATTL, Canon uses a preflash to *actively* judge subject distance  rather
than  passively.   This  factors  in light loss from bouncing off different
kinds of surfaces (for example, flash modifiers), and  light  *gains*  from
bouncing  off  different  kinds of surfaces (like ceilings and walls).  You
simply cannot make the remotest use the GN calculations  for  anything  but
direct flash.

Personally, I avoid direct flash, and most light  modifiers  are  bound  to
void  the  GN  calculations,  either because of light loss, or because they
require the head to be up (like the Lumiquest pocket bouncer).  So for most
shots, the distance information would have to be thrown away.


2.11.  How can I find out more about using flash with my EOS?

Canon  publishes   the   "Speedlite   Reference   Guide".    Stephen   Page
<sdpage@andersen.co.uk> posted the following summary:

>From: sdpage@andersen.co.uk (Stephen Page)
>Newsgroups: rec.photo
>Subject: Canon Speedlites: What the Manual Doesn't Tell You
>Message-ID: <1992Aug3.212808.4657@andersen.co.uk>
>Date: 3 Aug 92 21:28:08 GMT
>Organization: Andersen Consulting (UK Practice)

Many thanks to someone (sorry, I've lost the posting!) who passed on a
tip about the Canon USA booklet, "Speedlite Reference Guide" (Chuck
Westfall, 1991). This is an excellent little book and it contains some
essential information which Canon have not bothered to tell the world
in their instruction manuals.

The booklet can be obtained from Canon USA, One Canon Plaza, Lake Success,
NY 11042, USA; telephone +1-516-488 6700. They sent mine immediately and
there was no charge.

I've summarised some key points below which may help others. Do get the
book, though; it's got lots more of the same. Also write to Canon and blast
them for a pathetic user manual...  I cannot see how anyone could work
out how to use the flash correctly without this book.

My summary is valid for EOS-1/430EZ; other models have slight differences.
Early models of Speedlites work differently.

[ P.S.: Anyone know if Canon have any other hidden reference guides from
  national offices in the US or elsewhere?? ]

-----

1. Types of flash exposure.

In "normal" flash exposure, the exposure is calculated for the foreground
subject and the background is underexposed.

In "fill-in" flash exposure, the shutter speed and aperture are set to
expose the BACKGROUND correctly. The flash duration is adjusted to expose
the subject correctly. The Speedlites operate in fill-in mode most of the
time (see below).

2. Flash exposure and the camera modes.

In Program mode, the camera will use fill-in exposure provided that the
light level is EV10 or above. If the ambient light is below EV10, the shutter
speed will be locked at 1/60 sec and the flash will work in "normal" mode,
i.e. the background will be underexposed.

In Aperture-priority (Av) or Shutter-priority (Tv) modes, the camera will
ALWAYS use fill-in exposure mode. The exposure will be set to match the
background (ambient light level), so if the ambient light is low then a
slow speed and/or large aperture will be selected.

3. Tinkering with the light levels.

When the ambient light is above EV10, the Speedlite's flash level is reduced
on a linear scale to a maximum of the equivalent of 1.5 EV steps less than
the standard exposure level (at EV13 and above). This is to preserve the
natural lighting a bit, by not blasting it away with flash.

4. Exposure compensation.

The exposure compensation controls on the camera affect BOTH background and
foreground exposure.

To adjust the foreground independently of the background, use the control
on the flash (430EZ) itself.

5. A-TTL vs TTL.

The Speedlites can be switched to use "TTL" rather than the default "A-TTL"
mode. Some flashes, e.g. ring flash ML-3, only use TTL mode.

TTL mode disables the preflash (near-infrared in normal flash head position,
white in bounce position). This has the advantage that it doesn't make the
subject think that the picture has been taken, and it doesn't set off any
slave units. However, in TTL mode you get no pre-exposure distance measurement,
so the camera can't scream if you are out of range. You can work it out by
using the distance scale, or by looking at the indicator light AFTER the
flash.


I hope this helps some of you to work out the mysterious behaviour of your
equipment!!


===============================================================================
      Stephen Page, Manager, Technology and Systems Integration Division,
         Andersen Consulting, 2 Arundel Street, London  WC2R 3LT, UK
  Phone: +44-71-438 5074 (direct)  Fax: +44-71-831 1133 (work) 731 1737 (home)
               Voice mail: +44-71-438 2121 password 973 id 5074
           Email: sdpage@andersen.co.uk  or  uknet!aclondon!sdpage



3.  Lenses:

For a comprehensive chart of Canon  lens  offerings,  please  consult  Paul
Repacholi's EF lens guide.


3.1.  Can I use my FD-mount lenses on EOS bodies?

There is a mount converter from EOS to FD, but  it  is  a  MACRO  converter
only!   That is to say, it does not allow the fitted FD-mount lens to focus
to infinity.  In addition, it does not work with cameras that do  not  have
interchangeable  focusing screens, and certain FD lenses might not fit!  (I
don't know why not.)

(If anyone can give me a good summary on this, I'll gratefully accept it.)


3.2.  Can I use EF-mount lenses on FD-mount bodies?

No.  First, the EF mount is *bigger* than the FD mount.  Second, the  adap-
tor  would  have  to convert the mechanical aperture setting action for the
old FD lenses into *electrical* information for the EF lenses.   Since  you
can't  stop  down  an  EF  lens  mechanically, even if you had stopped-down
metering, you'd still be stuck.

It would require quite the contraption to make EF lenses work, and is prob-
ably not worth anyone's effort to research and develop.



3.3.  Why have the focusing motor in the lens?

Having the focusing motor in the lens allows the lens to have a motor  that
is  "matched"  to  its focusing characteristics.  Heavier glass can be sup-
plied with more powerful motors.  It should also simplify lens design since
there is no need to design a transmission that takes mechanical energy from
a fixed point in the lens mount to some other point in the lens.  With  the
motor  in  the  lens,  the  motor  can be placed where ever it will be most
effective.

3.4.  Doesn't the motor in the lens make the lenses more expensive?

In some cases, it probably does.   If  the  retail  prices  of  third-party
lenses  is  any indication, the motor does cost something (comparing a 3rd-
party Nikon AF mount lens to its Canon EF mount equivalent).  However,  the
lenses  from  Canon are generally regarded as faster focusing, so it may be
worth the extra money.


3.5.  Manual focusing with USM lenses?

There are two varieties of USM lenses.  One variety, commonly found on  the
"L"  series  lenses,  converts  rotation  of  the manual focusing ring into
electrical pulses, which in turn are converted  into  motor  movement.   On
such lenses, the ring is referred to as an "electronic focusing ring".  The
benefit of this system is that some of the "L" lenses can be  set  to  dif-
ferent  focusing  ring sensitivities to allow for speed or precision as the
user requires.

By default, the electronic focusing ring is disabled after AF since leaving
it  enabled  draws significant amounts of power from the battery.  However,
on some bodies, the electronic focusing ring can be  left  enabled  via  CF
after AF for "fine tuning" of focus by the user.

Most other USM lenses have  a  mechanical  coupling  that  works  after  AF
regardless  of  the  custom function setting.  Though this draws no battery
power, the angle of  rotation  from  close-focus  to  infinity  is  usually
regarded as too short.



3.6.  Can small animals hear USM lenses?

It appears so.  Some, but not all, USM lenses seem particularly annoying to
cats.


3.7.  Is there any way to focus a USM lens without annoying the cat?

On USM lenses with electronic focusing  rings,  it  appears  not.   On  USM
lenses with mechanical couplings, use manual focus.


3.8.  Canon lenses look too expen$ive.  What about third-party?

Because of the built-in motor, 3rd party lenses for EOS are generally  more
expensive than their non-EOS counterparts.

Canon has been pretty secretive about their  lens  interface.   There  have
been  a  few  postings  to the net implying that Sigma lenses don't AF very
well on Canon EOS cameras, or if they do, they only do  so  for  a  limited
time before failing.

Generally, Canon lenses are of similar or better quality in  comparison  to
similarly  priced  competitors.   It  is probably better to assume that you
will be staying with Canon lenses.



3.9.  Why didn't Canon think of using distance information (like some other
nameless company :-)?

Ahem.  With the release of the EOS 10s in 1990, the  following  USM  lenses
were introduced and return focus distance information:

        EF 35-135mm f/4.0-5.6
        EF 70-210mm f/3.5-4.5
        EF 100-300mm f/4.5-5.6
        EF 100mm f/2.8


I imagine all USM lenses since then include focus distance decoders.   How-
ever,  Canon  doesn't  claim to use the information for anything.  (Look in
the "Flash" section on why distance information is not too useful.)


3.10.  So what are affordable Canon lenses worth getting?

The following 3 lenses are mentioned on the net repeatedly for  being  able
to  produce  good  quality  images  at  a reasonable price (maybe this info
should go into the EF lens guide???):

EF 28-70/3.5-4.5 II:
     This lens boasts an aspherical element to improve its performance when
     shooting wide open.  It is regarded as being one of the best lenses in
     its focal length and slightly better than the 28-80/3.5-5.6  USM  that
     replaces  it.  The factors against this lens are: a) the front element
     rotates, b) the filter threads retract at middle focal lengths, c) the
     filter  size  is  52mm  rather  than  the 58mm that Canon seems to now
     favour, d) they are becoming very scarce.

EF 100-300/4.5-5.6 USM:
     Noted for its fast focusing, it is supposed to be "quite good but  not
     outstanding".   The  main  complaint  is  that  it  suffers from "zoom
     creep".

EF 100-300/5.6L:
     This is supposed to be the sharpest lens in its focal length, and  the
     cheapest  of  the  "L"-series  zooms (nearly half the price of the 80-
     200/2.8L).  Main weaknesses are that it has a push-pull  zoom  mechan-
     ism,  it's  slow  focusing, the front element rotates, and the maximum
     aperture is quite modest.


3.11.  My lens cap is too loose.  What can I do?

There are a few solutions:

a)   Buy a "cap keeper" gizmo that strings your cap to  your  lens.   (Most
     people  don't  like  this  idea  because  it  reminds  them of "mitten
     strings"...)

b)   Pop the spring mechanism out of the cap, heat with a hair drier  while
     applying  force  to  mold the ring into the desired shape.  An elastic
     may be found useful.

c)   Just screw the cap into the  filter  threads.   My  caps  stay  snugly
     attached this way!


3.12.  Can I use the Canon EF teleconverters on my EF lens?

The Canon EF  teleconverters  are  specifically  matched  to  fit  specific
telephoto  lenses  from  the  "L"-series.  Physically, they have an element
which is supposed to protrude into the lens itself.  Most EF lenses  aren't
designed to accomodate this.  Even if they do, they were not matched to the
teleconverter and thus will probably degrade image quality significantly.

There are 3rd-party manufacturers of teleconverters for  EF-lenses.   There
have  been  a  number of good reports on the Tamron 1.4x and 2x EF telecon-
verters.  However, all teleconverters will degrade image  quality  to  some
extent, particularly at the edges.  It is probably worth testing any candi-
date teleconverter with your lenses to see if the image  quality  is  still
acceptable to you.


3.13.  My lens pulls its filter threads inside the lens barrel  and/or  the
filter threads turn during focusing.  How can I use a circular polarizer?

Many of Canon's wide angle to short-telephoto EF zoom  lenses  retract  the
filter  threads  into  the  lens  barrel at middle focal lengths.  The most
popular examples of lenses with this problem are  the:  35-70/3.5-4.5,  28-
70/3.5-4.5,  and  28-80/3.5-5.6.   This  can  make it difficult to turn the
polarizer.  In addition, the filter threads on  these  lenses  turn  during
focusing.

The most important thing is to make sure  that  the  filter  you  buy  fits
inside  the  lens  barrel.  Avoid circular polarizers with little knobs and
other protrusions.  If you explain your situation, most retail stores  will
allow you to test the fit of a filter on your lens.

If the filter threads turn during focus, focus first, orient the  polarizer
to taste, then take the shot.

If you are lucky, the filter ring will extend far enough forward  to  allow
you  to  turn  the filter.  There probably won't be much extrusion, so care
must be exercised to avoid getting fingerprints on the filter.  If there is
no way to reach the filter ring, you can set the lens to one of the extreme
focal lengths so that the filter ring is accessible, set the polarizer, and
then reset the focal length.

It may be worth trying extending the filter ring with  a  skylight  filter,
or,  better yet, just the filter ring of an old filter.  Many larger camera
stores have old filters for under $1.  Try to remove the filter element  by
popping  the spring, or simply smashing out the glass (with eye protection,
of course).  Make sure not to deform the filter ring.  Examine the  corners
of your negatives for vignetting at short focal lengths.


3.14.  How can I use a rubber lens hood if my front filter threads retract?

You're not supposed to.  Canon makes specially-matched hoods that  clip  on
the  outside  of  the lens barrel.  This leaves the filter threads free for
filters.  Read the specification sheet that comes with the lens  to  deter-
mine how many filters are can be installed on your lens without vignetting.

Since the lenses with this problem are lenses with a wide-angle end anyway,
a  lens hood probably won't help much with flare anyway (though purists use
lens hoods with 20mm lenses, so you be the judge).

The type of hood required is listed on the sheet and printed on the outside
of the packaging, so you don't have to open the box to figure out what hood
you need.


3.15.  What are TS-E lenses?

The "TS-E" designation is for "Tilt and Shift for EOS".  These lenses have,
to  a limited degree, movements like that of a view camera.  In particular,
they can be tilted and shifted relative to the film plane.  Without getting
into  view-camera  specifics, let it just be said that this kind of lens is
popular for use in architectural photography because the  tilt  allows  for
the correction of "converging verticals" in shooting situations that do not
allow one to get a better angle from which to photograph a building.

Current TS-E lenses are all manual focus.  [Any good reason for this?]


3.16.  Why are TS-E lenses so expensive?

Because of the movements, the image circle must be larger so  that  tilting
the  lens  still  puts an image on the film.  This involves more glass.  In
addition, there are many more moving parts.  Finally, these  are  specialty
lenses that are not in large-scale production.


3.17.  Why should I use an EOS-1 with TS-E lenses?

Certain combinations of tilt and shift will still move  the  limit  of  the
image  circle  onto  the  film  plane.   Since  the  EOS-1  features a 100%
viewfinder, it is easy to determine when this has occurred.


4.  Focusing:


4.1.  Manually focusing doesn't give me the AF confirmation light.   What's
wrong?

In most autofocus cameras, light has to get to 3 different places: the film
plane, the viewfinder, and the AF module.  (Usually, the exposure is deter-
mined from light bled from the viewfinder image.)  It is possible that they
are  not  perfectly  aligned, resulting in differences in the length of the
light path, and ultimately, disagreement as to what is "in focus".

The disagreement between the AF module and  the  focusing  screen  is  more
readily  apparent  in  cameras  with  focusing  screens, or when using long
lenses with large apertures (i.e. shallow depth of field).  If your  camera
is  under  warranty,  it  is probably worth calling Canon service to see if
they can check the alignment for you.

If you must test it yourself, try any of the "home brew" lens  tests.   Set
yourself  up  with high-resolution (i.e. slow) film, a tripod, and a target
of some kind (a page from a  newspaper  with  varying  type  sizes  is  the
cheapest).   Try shots with AF, using MF, and maybe a few others around the
distances selected with either of the first  two  methods.   TAKE  DETAILED
NOTES!

Then, decide for yourself if you've lost any sharpness and whether you want
to take your camera in for adjustment.

EOS cameras with interchangeable  focusing  screens  seem  to  have  better
correlation between AF and MF.  This is probably because Canon assumes that
someone who wants interchangeable screens wants to use a focusing  aid  and
manual  focus  at least some of the time.  Cameras with fixed matte screens
are assumed to be manually focused rarely, if at all.



4.2.  Why is the manual focus throw so short?

On most of the non-professional lenses, the focus throw is short  to  allow
for  quicker  AF.   To  keep costs down, only a simple gearing mechanism is
provided for MF, making the throw slightly longer, but still not that  pre-
cise.

On some "L" lenses with USM, there is "electronic gearing" with the  "elec-
tronic  focusing  ring".   Indeed,  the gearing can change depending on the
focal length setting of the zoom lens.  On "L"  lenses  with  AFD,  a  more
sophisticated gearing mechanism is included to give longer throw.


4.3.  So what techniques are there for precise manual focus on an AF lens?

1)   To get more precise movement of  the  focusing  ring,  grip  the  ring
     towards its back edge so that your fingers also touch the lens barrel.
     This will give more friction, a slower turning speed,  and  therefore,
     more  precise  focusing.  By varying the amount of pressure put on the
     lens barrel with your fingers, you can vary  the  amount  of  "braking
     force",  and therefore the precision of focus.  [This is the technique
     I used for precise adjustment of Apple ][ game paddles in my  "youth".
     :-)]

2)   Another technique  is  to  use  just  one  finger  to  focus.   Gently
     tap/nudge  the  focusing  ring in the direction you want it to travel.
     The theory is that you shorten the amount of time you are manipulating
     the  ring, and thus don't "overshoot" the zone of precise focus.  This
     technique can be combined with the first.  [This second technique  was
     told  to  me  by a salesman at a local camera shop.  I've never gotten
     much out of it, but it is included "just in case".]


5.  Viewfinder:


5.1.  I wear glasses.  Can't see all of viewfinder and/or  the  information
display.  What can I do?

Just remove the rubber eyecup.  It'll allow your eye to get  closer.   How-
ever,  it  is  worth  checking to see if the plastic around the eyepiece is
abrasive to your glasses (particularly plastic  lenses,  or  special  coat-
ings).   Rub  the exposed eyepiece frame briskly on a remote corner of your
vision-correcting lens, or on an old pair of glasses.


5.2.  Why can't I focus on both the viewfinder image and/or the information
display?

The two virtual images are projected at different distances.  Try borrowing
a  technique  from  microscopy.   That is, look through the viewfinder with
both eyes open!  By doing so, you may be able to "fool" your viewfinder eye
to  focus on a farther point; one that may be closer to the distance of the
images in the viewfinder.

It may also be worth trying out  some  diopter-adjustment  lenses  for  the
viewfinder.   These  are  usually selected by trial-and-error, so you might
have to search high and low for a Canon dealer with  a  good  selection  of
them in stock.


5.3.  What's the eyepiece cover for?

It blocks stray light from entering viewfinder when your eye is not  up  to
the  eyepiece--like  when  shooting  from  a tripod.  Since the exposure is
determined from light bled from the viewfinder image,  light  entering  the
pentaprism  could  find  its  way to the exposure sensor.  This could cause
underexposure.

There is nothing terribly special about this piece.  If you lose  it,  just
remeber  to cover the eyepiece with your hand or something else opaque when
the exposure reading is being taken.


6.  Miscellany:


6.1.  Can I get warranty service, even if I didn't buy it in this country?

It is the policy of Canon USA and Canon Canada to honour  the  warranty  of
any  Canon product regardless of how it is purchased.  However, this may be
subject to parts availability.  That is, parts may  not  be  available  for
items  that  are  not normally available in the USA or Canada (for example,
the EOS 10 QD).  Call Canon to confirm warranty service on esoteric items.


6.2.  How Do I Leave the Film Leader Out?

Some EOS bodies have a custom function which leaves  the  film  leader  out
after  rewinding.   For  those of you without access to such a custom func-
tion, I suggest you find a film-leader retrieval tool.


6.3.  Where do I Get a Film Leader Retrieval Tool?

You'll probably be more likely to find one at a store  which  also  handles
darkroom  equipment,  since  some people like to wind their film out of the
cassette onto the developing reel (rather than prying the cassette open  in
the dark).

I have the ability to leave the film leader out on my 630.  I used to think
it was a highly useful thing, but too much film handling does risk scratch-
ing the negative, or even accidentally exposing some film.  So these  days,
I try to avoid it for anything critical.

For the few times you'll use it, I don't  think  it's  something  to  worry
over.   Film  is  relatively  cheap compared to the anguish of messing up a
good shot...




6.4.  How do I get exposures longer than 30 seconds?

The EOS-1 can have longer exposures with the Command Back E1 and 600-series
can do it with the Technical Back E.  Otherwise, use Bulb mode.


6.5.  What's a Technical Back E?

Here is some information on the capabilities of the Technical Back E
(TB-E).  Much, but not all, of the information comes from "How to
Select and Use Canon EOS SLR Cameras" by Carl Shipman, (C)1989.  The
information is not taken verbatim, and the editorial comments are mine,
but I'm attributing anyway (just to be safe).

The Technical Back E is designed to be used with the EOS 620, 630, and
650.

It has a sizable LCD panel which is organized with one line of 14
character cells, a "dead zone", and 3 more lines of 14 character
cells.  Each character cell appears to be 7x12 pixels.

It has 9 buttons under an all-too-familiar 600-series type door, but
longer of course.  The buttons are labeled (left-to-right): Menu,
Submenu, On/Off, Set, Left/Select, Right, Up, Down, Start/Stop/Clear.


Technical Back E Capabilities:
-----------------------------

Notes:
  - memorize 4 notes of 30 characters

Imprint:
  - imprint up to 3 of the following: date, time, shutter and aperture,
     exposure mode, film counter, or a note

Data Storage:
  - store exposure information and download to a computer
     or view on LCD panel
  - can store 361 frames worth of the following information:
     serial number or cartridge number, frame number, exposure mode,
     metering mode, flash used or not, shutter speed, aperture,
     focal length, exposure compensation, film speed, date, time, and note
  - alternatively, can store 824 frames worth of the following information:
     serial number or cartridge number, frame number, exposure mode,
     flash used or not, shutter speed, aperture, and focal length

Custom Program Curves:
  - draw a program curve on the LCD display
     [I don't know if it actually gives access to the 6 segments.]
  - two curves can be stored

Automatic Exposure Bracketing:
  - Allows up to 9 frames +/- 2 stops in 0.25 stops

Exposure Timer:
  - interval timer
  - long exposures

Imprint Data Correction:
  - data is not imprinted until rewind, so editing of memorized
     imprint data is possible


Accessories:
-----------

Keyboard Unit E:
  - Holds 4 extra notes that can be exchanged with the TB-E
  - Can swap memory dumps from the TB-E for storage
  - allows for more convenient user interface

Interface Unit TB:
  - Connects IBM PC or MSX PC via RS-232
  - Dump data from TB-E for printing
  - Design special characters for imprinting
  - Preset imprint data for 36 frames to be written onto frames
  - Control of timer functions


The TB-E predates the 430EZ, so there is no control over flash
exposure compensation.  (Indeed, it doesn't seem to have any flash
control at all.)

Sounds like lots of intriguing features in there.  Too bad it was so
expensive.  Musta been loads o' R&D for something that they couldn't
have sold too many of.  (Maybe it was a debugging platform for the
original EOS bodies?  Hmmm...)

ACS


6.6.  How do I use bulb mode without shaking my camera?

For cameras with IR remote capability, use the IR remote.

On the EOS-1 and 600 series, there  is  an  accessory  called  the  "Remote
Switch  60T3".   It  is a 3-terminal switch with a 60cm cord that can sense
when the button has been pressed half way.  It plugs into a special  socket
at the base of the grip.  The button can be locked down by sliding the but-
ton forward.

If an adaptor to a standard cable  release  is  required,  use  the  "Cable
Release Adaptor T3".  Many cable releases provide a locking mechanism.

The Remote Switch T3 is generally regarded  as  more  convenient  since  it
gives  better  feedback  as  to when the switch is pressed half way, is one
piece, and is faster to operate.


6.7.  Where is this socket on the 630, 650 or RT?

The 650, 630, and RT require the purchase of a replacement grip, GR20.   It
is identical to the standard grip (GR30), but has the appropriate socket.


6.8.  How do I get long exposures on the Rebel/EOS 1000?

Unfortunately, there is no elegant solution.  However, there  are  manufac-
turers  of  accessories  that place a cable release socket over the shutter
release.  Some take the form of a metal bar that  screws  into  the  tripod
socket  and holds the cable release socket in position.  Others are a strap
of velcro which do the same.  [I believe Kaiser manufactures such an  item,
but I have never tried it.--ACS]


6.9.  I need a manual for my Canon camera.  How do I get one?

Call your closest Canon office and ask them for one.  There may be a fee on
the order of $5 to $10 depending on the manual.


6.10.  How can I shoot more than 36 exposures on an EOS-1?

It appears that there is no way so far.   The  camera  cannot  be  made  to
ignore  the  DX-ed  film  length, and on film cannisters without DX'ed film
length, the camera will stop at 36 frames.  Jim  Cathey  hypothesizes  that
with  the  faster  (5fps) film transport that first appeared on the 630/RT,
that Canon might worry about tearing the film off the spool.


6.11.  What is Canon's phone number?

The Canon Consumer Information Center's number is 800-828-4040.  Avoid cal-
ling  between  12  and 2 o'clock eastern time when they are 1/2 staffed for
lunch.  Canon Canada can be reached at 416-795-1111.  (I don't know  of  an
800 number.)


7.  Bodies:


7.1.  What's an EOS RT?:

The EOS RT is a specialty camera based on the EOS 630.  Features it  shares
with  the  630 include:  interchangeable focusing screens, 5ps motor drive,
faster AF than the original 620/650.  It also shares the limitation of  not
being able to use the fully dedicated off-the-camera flash cord for ATTL.

The EOS RT has a fixed mirror that allows the photographer to view the sub-
ject in "Real Time" as the exposure is being made.  The viewfinder does not
"black out" because the pellicelle mirror is not moved  out  of  the  light
path.  This costs 2/3 of a stop of light.

Other features over the 630 include: centre-weighted metering, 15 CF's.

Main Uses for an RT:

        Sports photography: allows panning during the exposure.
        Certain kinds of flash photography: can visually see the flashes
           firing.
        Macro photography: mirror is permanently locked!
        Special effects: painting with light, or zoom effects.


One point about the fixed mirror in the RT  is  that  dirt  on  the  mirror
*will*  affect  the  final  picture!   Since mirrors are difficult to clean
properly, it is better to avoid changing  lenses  on  the  RT  in  a  dusty
environment.


7.2.  Is the EOS Rebel/1000 any good?

This line of cameras is aimed at the consumer market and  is  considered  a
bargain  considering  the  amount  of  technology  that is included for the
price.  Question has been raised as to whether it is  sufficiently  durable
under  heavy use.  However, no one on the net has complained of malfunction
during actual use.


7.3.  What's an EF-M?  The Rebel is only $30 more!

An EF-M is a manual-focus only body which requires EF lenses.  It  features
a  split prism focusing aid with microprism collar.  Most view this item as
being a terrible idea since most AFD lenses don't  MF  that  smoothly,  and
most of the EF lenses have too short a focusing throw.

My guess is that these cameras were designed for the  "educational  market"
for  students  who have instuctors insisting that they get a Pentax K-1000,
or something equally limited.  Once the course is done, they could  get  an
AF body(?).


7.4.  Can I use IR film in the EOS Elan/100?

No.  The Elan uses an IR LED to detect the movement of the sprocket  holes.
In addition, the remote release and bar code reader also emit IR.


7.5.  What is in those bar codes?

Thomas Greve <greve@isa.de> has decoded some of the barcode information:

>From: greve@isa.de (Thomas Greve)
>Subject: Re: Auto Focus Button, about the EOS barcode
>Message-ID: <1992Sep11.111442.706@isa.de>
>Sender: usenet@isa.de
>Nntp-Posting-Host: escher
>Organization: ISA Gmbh, Stuttgart, FRG
>Date: Fri, 11 Sep 1992 11:14:42 GMT


-  the format of the barcode is the 2/5 interleaved
-  it contains 14 or 16 digits
-  the first digit is a 0 if 14 digits are used
-  the first digit is a 1 if 16 digits are used
-  the EOS 10 barcode book only uses 14 digits for all programs
-  the EOS 100 (Elan) uses one code with 16 digits to clear programs

if the 14 digit code is used the digits have the following meaning


digit 1:  0 if 14 digits, ( 1 if 16 digits)

digit 2:                             digit 3:
        program                               transport / auto focus mode
        0: P (Tv + Av)                        1: single / OneShot
        1: Aperture priority (Av)             2: single / AI Servo
        2: Time priority (Tv)                 3: single / OneShot+AI Servo
        3: Depth of field (DOF)               5: multi  / OneShot
        4: Manual                             6: multi  / AI Servo
                                              7: multi  / OneShot+AI Servo
digit 4:                             digit 5:
        metering modes                        flash
        0: 6 field                            0: no flash
        1: 6 field                            2: flash always
           / exposure + 2                     3: flash always / flash + 2
        2: Selectiv                           4: flash if necessary
        3: Selectiv                           5: flash if necessary / flash + 2
          / exposure + 2

digit 6:                             digit 7:
        Program counter 10 x                  Program counter 1 x

digit 8:                             digit 9:
        digit 4 without correction:           digit 5 without correction:
        0: exposure:   0                      0: flash correction:   0
        1: exposure: - 1/2                    1: flash correction: - 1/2
        2: exposure: - 1                      2: flash correction: - 1
        3: exposure: - 1 1/2                  3: flash correction: - 1 1/2
        4: exposure: - 2                      4: flash correction: - 2
        digit 4 with  correction:             digit 5 with correction:
        0: exposure: + 2                      0: flash correction: + 2
        5: exposure: + 1 1/2                  5: flash correction: + 1 1/2
        6: exposure: + 1                      6: flash correction: + 1
        7: exposure: + 1/2                    7: flash correction: + 1/2
        8: exposure: + 2                      8: flash correction: + 2

digit 10:                            digit 12:
        shutter speed                         aperture
        1: 30     sec                         2: f-stop 2.8
        2: 8      sec                         3: f-stop 5.6
        3: 2      sec                         4: f-stop 11
        4: 1/2    sec                         5: f-stop 22
        5: 1/8    sec
        6: 1/30   sec
        7: 1/125  sec
        8: 1/500  sec
        9: 1/2000 sec

digit 11:
        Addition to values of digit 10 and 12:
        0:  time 0         / f-stop 0
        1:  time 0         / f-stop + 1
        2:  time + 1/2     / f-stop 0
        3:  time + 1/2     / f-stop + 1
        4:  time + 1       / f-stop 0
        5:  time + 1       / f-stop + 1
        6:  time + 1 1/2   / f-stop 0
        7:  time + 1 1/2   / f-stop + 1

digit 13, 14: ???



If the 16 digit code is used the meaning of the digits seams to be
totally different. I made some experiments, but never get qualified
methods. I think the first digit have to be a 1 but I am not sure.
If the most digits where set to 9 the EOS 100 worked with a correction of
3 1/2 EV or more.
With the code 1120000000805000 it is possible to clear a existing
program within the EOS 100.
Perhaps there are some goodies to manipulate the EOS 100 or EOS 10 ?

I called Canon Germany to get some information but they do not know
anything about the barcodes. So perhaps one of you could try this in your
country with more success ?

Thomas Greve


8.  Batteries:


8.1.  Why don't I get as much life out of my batteries as my  manual  would
have me believe?

The "Canon Test Method" usually assumes optimum conditions.   For  example,
battery  life  on  bodies is ususally performed with the lightest, cheapest
lens (50/1.8 II), and that there are 20 seconds between exposures.

The typical EOS user is a user of zoom lenses, which are bigger and heavier
than  the  50/1.8  II.   There  is also significant battery draw for simply
metering the scene, even if no exposure is taken, since all  of  the  elec-
tronics power up, and AF is activated.

For tests involving flash, it is assumed that the  flash  is  exactly  half
discharged on every shot.  With the A-TTL program, it attempts to stop down
as far as possible, meaning that the flash is closer to  fully  discharged.
With  built-in  flash,  you  lose light because you probably don't have the
50/f1.0L.  That is to say, you run into the guide number formula,  distance
= GN/aperture, and thus require a full flash.


8.2.  I just got my camera and have been  fooling  around  with  it.   I've
already lost two bars on the battery check, and I haven't even run any film
through it!  What's happening?

The main draws of power are the electronics and motors.  When playing  with
AF,  you're  activating  motors.  Also, when first familiarizing one's self
with a camera, one tends to leave the  display  on  for  longer  intervals.
When  any  switch is pressed, the camera electronics come on--even when the
main switch is the LOCK position!

Here are two ways to test this assertion:

1)   With the camera in aperture priority, set the minimum aperture for the
     lens.   Use  hold  down the DOF preview button, and then turn the main
     switch to "L".  Notice that the lens stays stopped down.   Remove  the
     lens.   It's  still  stopped  down.   Now reattach the lens.  As if by
     magic, the aperture opens again!

2)   With a 430EZ attached, turn the main switch to "L" and let  the  flash
     go  to  "sleep".  Depress the shutter button or flip the AF/MF switch.
     The flash wakes up!


8.3.  What are the "hard numbers" on battery use?

Robert M. Atkins posted a nice summary of measurements based  on  his  630.
Newer cameras may draw more power due to faster CPUs and more features.

From: ka1gt@cbnewsm.cb.att.com (robert.m.atkins)
Newsgroups: rec.photo
Subject: EOS battery use - Some hard numbers
Date: 23 Dec 92 23:43:12 GMT
Distribution: na
Organization: AT&T

I just measured some current draw data for an EOS 630 with a 35-135 USM lens
which might be of interest:

Lens focusing (from infinity to closest focus)  200mA for 0.25 seconds
Film winding (1 frame)                          600mA for 0.25 seconds
Mirror fliping up & shutter release             350mA for 0.1 seconds
Exposure determination (i.e. depress shutter
release 1/2 way to give exposure reading)       100mA for 6 seconds
Film rewind (36 exposures)                      450mA for 8.5 seconds
Any function button                             100mA
(current is drawn until function is set)

Maximum current drawn was a 1.6 amp transient on motor start up

Adding up these numbers you find that to focus from infinity to closest
focus, get an exposure reading and hold it for 5 seconds, release the
shutter and wind on one frame takes about 835 mA.seconds. Let's be
cautious and say I missed a few transients and assume the real value is
1000mA.seconds. To expose a full roll of 36 exposures and rewind it would
then require close to 40,000 mA seconds. A 2CR5 has a claimed capacity of
1300 mA.hr (= 4,680,000 mA.seconds), thus we should be able to get about
115 36 exposure rolls from a 2CR5!! However, if you focus a couple of times
and take 3 exposure readings every time you take a shot (which is not all
that unusual for the kind of work I do), then this number will drop by
a factor of about 3, to maybe 40 rolls per battery. This still seems a little
optimistic - maybe 2CR5s are not really 1300 mA.hr at the current draw rates
found in the camera?

The numbers do point out a few things thought. First, the small USM lenses
do not draw much power, so there would be little to be gained by using
manual focus. Second, the real power draw is when the shutter is depressed
1/2 way to get the exposure reading. If you don't take a picture you get
100mA draw for 6 seconds. If you do take a picture the current draw stops
after the frame is wound (i.e. less than the full 6 seconds). Lastly, there
is significant discrepancy between the claimed capacity of 2CR5s and the
resultant theoretical number of rolls of film you should be able to get
through the camera.

Happy Holidays to all

===============================================================
Bob Atkins  AT&T Bell Labs  email (direct)  att!clockwise!rma
===============================================================



8.4.  I'm down to one flashing bar.  Do I have to throw the battery away?

No.  You can run the battery down until it's completely dead.  It can  last
for  up  to 2 rolls of shooting.  However, it is a good idea to buy a spare
battery by the time the camera gives you one blinking bar.


8.5.  If I let the battery die, will I lose my film count or  custom  func-
tion settings?

No.  The EOS cameras are  designed  to  remember  their  state  information
between  batteries.   On the EOS-1, there is NOVRAM maintained by a lithium
button cell.  The cell is supposed to be good for 3 to 5 years (under  nor-
mal  conditions).   On  the  EOS  600 series, there is an EEPROM which gets
updated.  It is supposed to last through 10000 updates.  If it  wears  out,
it will need to be replaced by a Canon service centre.


8.6.  The 430EZ eats batteries too quickly.  How can I get more flashes out
of my 430EZ?

If all you want is "a little bit more", you might want to simply shop  more
carefully  when  buying  NiCad AA cells.  Some cells are rated for 600 mAh,
whereas others for 800 mAh.

Another option is lithium AA's.  They should be hitting  the  market  soon.
Popular  Photography  stated that one set of lithium AA's lasts about twice
as long as one set of NiCads.  However, lithium batteries are expensive and
are *not* rechargeable.


8.7.  What if I want a LOT more flashes and/or faster recycling (because of
fast action and/or cold weather)?

The 430EZ has a high-voltage jack.  It is designed to accept power from the
Canon  Transistor  Pack  E.   With  it,  recycling time can be reduced to 3
seconds and shooting capacity is on the order of 250  full-powered  flashes
with the NiCad pack.

The Transistor Pack E will accept 6 "C" cells, or a special NiCad pack from
Canon.   Canon  does not recommend using NiCad cells in the Transistor Pack
E.  (I have no idea why not.)

Canon warns the 430EZ can be damaged from overheating if  fired  at  faster
recharge rate provided by the Transistor Pack E.


8.8.  What about non-Canon high-voltage packs?

Canon doesn't  recommend  the  use  of  non-Canon  high-voltage  packs  (of
course),  but  no  reports (to my knowledge) of a 3rd-party pack damaging a
430EZ have been reported.

The most popular 3rd-party HV packs are based on lead-acid technology.   To
attach the pack to the 430EZ, an additional adaptor cable is required.

Damage to your flash as a result of connecting to a 3rd-party pack will (of
course) void the warranty.


8.9.  High voltage packs look too expensive.  What are my options?

A low-voltage pack.


8.10.  I don't have a high-voltage jack on my flash.  What are my options?

A low-voltage pack.


8.11.  What is a low-voltage pack?

A low-voltage pack connects to the  battery  terminals  of  the  flash  and
delivers  6V  at  a slightly higher current than NiCads would normally pro-
vide.  Some packs are just big NiCad batteries.  Others are lead-acid.

To get the power from the pack to the battery terminals, a  matching  "bat-
tery  adaptor"  is  required.   These adaptors are designed to fit into the
battery chambers of specific flash units.  Since there is no opening to run
the  cable  to the battery adaptor, the door to the battery chamber must be
left partially open, or a notch must be cut into the door.  In the case  of
the former, the battery door is usually held shut with a velcro strip.


-- 
 ___ ___ ___ ______________________________________________________________
|   |   | __|"The Nikon lens owners are more gratingly smug, while the     |
| - | --|__ | Canon lens owners are more verbally abusive." - Tony Arnerich|
|_|_|___|___|______________________________________________________________|
Alvin_C._Shih____________________acs@csri.utoronto.ca______________________|

From: johnson@hpcc01.corp.hp.com (Cole Johnson)
Date: Mon, 4 Jan 1993 17:35:57 GMT
Subject: Re: Looking for a good P&S
Organization: the HP Corporate notes server