HDTenEightyP/NetNews huggingface dataset:
From: tklai@acsu.buffalo.edu (Tobysze K. Lai)
Newsgroups: rec.photo
Subject: Advise on telephoto zoom lenses
Date: 27 Aug 92 20:22:15 GMT
Organization: UB

Hello there,

	I am looking for a mid-price telephoto zoom lens for my Canon EOS
camera.  There are few choices in my mind now:

	Canon EF 75-300 f/4-5.6
	Sigma AF 70-210 f/4-5.6 APO
	Sigma AF 75-300 f/4-5.6 DL

	The main thing I am concerned with is the quality of the lens, and
I am not really care about the focusing speed of the lens, although I know
that the focusing speed of the non Canon-made lens won't be as fast as the 
one made by Canon.  Does anybody own or has any experience with any of the
above lens?  Thanks in advance for any advise or comments!


Toby Lai
tklai@acsu.buffalo.edu
Newsgroups: rec.photo
From: jay@metran.UUCP (Jay Ts)
Newsgroups: rec.photo
Subject: Re: question about night photography
Date: 3 Sep 92 23:06:30 GMT
Organization: Metran Technology, Tampa, Florida

gsnow@clark.edu (Gary Snow) writes:
: In article <1992Sep1.211030.7240@TorreyPinesCA.ncr.com> dhr@TorreyPinesCA.ncr.com (Dan Harlow 3551) writes:
: >
: >I would love to take pictures of the beautiful San Diego skyline at
: >night, with all the lights and the hills and the lit up towers.
: 
: First rule, don't shoot prints, shoot slides. Photo finishers will just
: turn your nice black buildings and such (with lights all around) into
: a muddy brown color.

Absolutely.  Just about all scenes like the one you describe are very
high contrast; probably, the lights in office buildings will have to
really burn in if you are going to see details in anything else.  One
really good way to get around this is to shoot at dusk, just after the
sun sets.  If you start then, you will be able to catch a magic minute
or so when the fading sunlight is matched to the brightness of the city
lights that have just switched on.

: Another good rule of thumb is that longer exposures will give you more
: light saturation then shorter ones, and its a good idea to bracket as well.

Exposures may easily be longer than 1 second, so reciprocity failure of
color film quickly comes into play; you will get loss of film speed along
with color shifts.  I have had some good results using Ektachrome 64x at
night (exposure around 3 minutes at f/8).  Velvia and Fujichrome 100D are
neat if you desire a lot of green "enhancement".  You may need to bracket
quite widely, so be prepared to use up a lot of exposures finding out
what works.  The exposure depends a lot on local conditions, phase of
the moon, and weather (seriously!).  The film's speed is not as important
as its reciprocity characteristics!  Have fun!

Jay Ts
From: mvolo@ecsvax.uncecs.edu (Michael R. Volow)
Newsgroups: rec.photo
Subject: Re: WANTED: condenser lens(es) for Omega D-3 enlarger
Keywords: condenser lenses, Omega D-3 enlarger
Date: 2 Sep 92 03:27:52 GMT
Distribution: usa
Organization: UNC Educational Computing Service


You can buy many bits and pieces of out-of-production Omega enlargers from:
Harry Taylor, Classic Enlargers, 145 Jeanne Ct., Stamford, Conn, 06903, (203)
329 9220. I've dealt with him, he's fair and honest.
-- 
Michael Volow, Psychiatry, Durham VA Med Center, Durham NC 27712
919 286 0411 Ext 6933               mvolo@uncecs.edu
From: honna@cs.concordia.ca (SEGEL honna)
Newsgroups: rec.photo
Subject: Re: Reloading throw-away cameras
Date: 27 Aug 92 16:52:05 GMT
Organization: Computer Science, Concordia University, Montreal, Quebec

In article <71617@apple.Apple.COM> bc@apple.com (bill coderre) writes:
>
>I'm sure this would be an FAQ, but I haven't seen it in the last
>thousand or so articles, so I ask:
>
>I know I CAN reload my fairly wonderful FUJI Quicksnap Flash camera,
>but I am wondering if any of y'all have the info-structions I need to
>avoid having to think for myself.
>
>Thank you for your kind indulgence!
>
>bill coderre
>getting the film OUT was the easy part!
If I understand your request correctly...
The ticket here is to load the camera in a changing bag or in a light-
tight container/room so that the cassette itself is Empty; when you 
wind and expose the film iteratively, frame by frame, you are winding
the film back into the cassette.  The only trick I can think of that
you might be lacking is how to tightly wind the *loose* roll of n dozen
frames so that you can position the film and the cassete And close up
the body without screwing up...By now a solution should be dawning.

HS/ Michael

-- 
***************************************************************
honna segel
department of computer science
concordia university  *****************************************
From: johno@sdd.hp.com (John Ongtooguk)
Newsgroups: rec.photo
Subject: Re: Nikon N90 technobabble
Date: 4 Sep 1992 19:00:27 GMT
Organization: Hewlett-Packard, San Diego Division
Distribution: world
NNTP-Posting-Host: hpsdlg10.sdd.hp.com

In article <13270@texsun.Central.Sun.COM>, dbernard@thewho.Central.Sun.COM (Dave Bernard) writes:
|> 
|> > recent FM2's use the same shutter as the N8008 and call it the FM3.
|> 
|> I haven't heard of the FM3.  Supposedly it's this specific shutter which
|> makes the N8008 unable to support mirror lock-up (the F4 uses a second
|> shutter or something to overcome the light-leakiness of the 8008). Does
|> this mean the FM3 no longer has pseudo mirror-lockup? (the mirror locks
|> up as soon as the self-timer starts. before the shutter actually
|> fires). If the FM2 sacrificed pseudo mirror lockup for this faster shutter
|> I call it a net loss.

   Don't think it did, although the pseudo mirror lock-up was never 
   'officially' supported as multi-bladed shutters seem to need a
   blind to keep light tight during mirror up conditions. The F3
   had a foil curtain shutter as I recall, which is of course 
   light tight. Evidently they also added a shutter/mirror damping 
   device to the new version, which is nice. Now if theu would
   only put in a spot meter....or even replace the standard center 
   weighting with one having heavy center weighting.... 

   John Ongtooguk (johno@sdd.hp.com)
Newsgroups: rec.photo
From: Robert Drongowski <Robert.Drongowski@cc.umich.edu>
Subject: Re: Inrared Photog + Spider Webs
Date: Mon, 31 Aug 92 12:49:51 EDT
Organization: Pediatric Surgery, U of Michigan
X-Useragent: Nuntius v1.1b2

Infrared Photog + Spider Webs
	Can anyone offer suggestions or their experience regarding
picture-taking of spider webs with Infrared film.  I have taken many web
pictures with both B&W and Color film with reasonable success.  However,
a small article in Science a few years back indicated that taking
pictures of webs with infrared film produces a unique glow within
portions of the web structure which mimics flower structures etc.  The
example they printed in the article was fairly neat, with one strand of
web highlighted from oputside to the very center of the web (which
presumably acts to attract insects etc).
	I subsequently shot a number of webs with no noticeable effect with the
film I used; ie. It looked like regular black and white film without any
effect of Infrared.  However, a few flowers that I shot did produce an
unusual effect which indicated to me that the film was "good".  I know
must one take extreme measures in handling the film (refrigerated,
absolutely no light while loading/unloading film, etc).
	Does anyone know if it's only certain spider-webs which produce this
result?  Are there any other tricks using infrared film which could
enhance my chances for success?
Could the developers have used a different method to enhance the effect?
Thanks for any suggestions, they are well appreciated.
BOB DRONGOWSKI,  Ann Arbor, Michigan
From: gsnow@clark.edu (Gary Snow)
Newsgroups: rec.photo
Subject: Re: Guide No for Max 5400xi Flash?
Date: 28 Aug 92 16:43:03 GMT
Article-I.D.: clark.1992Aug28.164303.752
Organization: Clark College, Vancouver, Wa.  USA

In article <92240.180927M05BC@CUNYVM.BITNET> M05BC@CUNYVM.BITNET (Spartacus@Cuny) writes:
>
>        Its been a while I've posted to rec.photo.  In the August issue
>     of POPular Photography, they reviewed the new 9xi and the 5400xi flash.
>     However they neglected to mention the new maximum guide number for
>     this new flash.  I would like to know how much better it is than the
>     5200i.  Would someone on the net know the guide number?

Simple, the guide numbers are incorporated into the Flash Name/Number. The
5200 has a guide number of 52 meters, and the 5400 has a guide number of 54
meters.

>        Also, POP didn't mention if the 9xi had rear-curtain sync.
>     Does it?  Oh..could you Email me your response...Thanks.

The 9xi doesn't have a built in flash, so how could it have rear-curtain
sync? Either of the above flashes will give it to you though when mounted
on a Minolta camera.

Gary

-- 
-----
Gary Snow
uunet!clark!gsnow  or  gsnow@clark.edu
From: bson@geech.gnu.ai.mit.edu (Jan Brittenson)
Newsgroups: rec.photo
Subject: Re: 1 day photo trips from San Jose, CA
Date: 4 Sep 92 05:36:51 GMT
Organization: nil

In article <1992Sep2.232703.19032@clark.edu> gsnow@clark.edu (Gary Snow) writes:

 > I would like to spend the day on nature photography, and would like
 > suggestions or comments on where I can go for this.

I can recommend two places well within a day's reach of San Jose.

   One is Fremont Peak, about 1-2 hrs south of SJ. Take 101 to 156, go
to San Juan Batista, take the windy road (G1) to the peak campsite.
The road may be hard to find - ask around in SJB. Spend the sunrise
around Fremont Peak, then drive back down and take a look at the San
Juan Batista Mission. A little touristy, but very original and quite
photogenic (i.e. the mission itself, not the town). Have breakfast in
San Juan Batista. Fremont Peak is great at sunset, but worthwhile at
sunrise as well. Just give the sun some time to burn off the fog. (If
I were you I'd go the evening before, bring a sleeping bag, climb the
peak and catch the sunset, then camp out overnight at the campsite.
You probably won't be alone - lots of amateur astronomers use the
site; great intelligent people to crack a beer with.) Bring food,
water, and a flashlight. Oh, you should drive the final part without
headlights if you arrive after dark/before sunset - out of
consideration for the astronomers.

   The second is Lick Observatory, east of San Jose. The road is
narrow and winding - you definitely will want to drive carefully. This
is a good spot for sunsets, but truly spectacular for night
photography. You'll have a fabulous overview of San Jose at night; you
can't imagine what it looks like until you've seen it! Looks good on
film, too. Due to the winding road you'll want to head out for it at
least 2-3 hrs before sunset. Take 280 east to 130, take 130 east to
the Lick Observatory.  You may want to stop a couple of times on the
way as there is some fairly photogenic nature along the road. It's all
private property, though, so be careful not to trespass. Give it an
hour or two to get really dark before trying to capture the "giant lit
cobweb." Shoot at least one roll of tungsten-balanced, and bracket
generously. I'd recommend focal lengths around 70-300 mm and slide
film.

   On a scale 1-10 I'd rate both of these at 7-8. Not the ultimate,
but definitely worthwhile quality excursions.


 > Please Reply to the address below or post to this newsgroup, as I have
 > asked someone else to post this for me.  (I read this newsgroup too
 > frequently).

   Perhaps Someone could also collect the responses and forward them
to you?

--
						-- Jan Brittenson
						   bson@gnu.ai.mit.edu
Newsgroups: rec.photo,alt.cd-rom,gnu.misc.discuss,misc.int-property
From: zrepachol@cc.curtin.edu.au (Paul Repacholi)
Subject: Re: Time to boycott Photo CD NO!
Organization: Curtin University of Technology
Date: Tue, 1 Sep 1992 07:45:48 GMT

In article <q#hnsg=@dixie.com>, jgd@dixie.com (John De Armond) writes:
> zrepachol@cc.curtin.edu.au (Paul Repacholi) writes:
> 
>>I have the 'Red Book' and friends. Free from Philips years ago. ALL the info on
>>formats ect... readily avail to anyone. The result of this is MANY people use
>>the format, and it becomes enormusly popular, and profitable.
> 
> And the Kodak data is available to anyone who wants it.  BTW, uh, where
> is the device you built that implements the "red book"?  Thought not.
> 

Want a Sony CDP-11S that can tell you raw data error rates?

>>I for one am looking forward to CDing *MY* images, and describing the full
>>details of the encoding of MY image on MY disk. I invite others to do the same.
> 
> I'll bet a C-note that this time next year you'll not have written anything
> usable that will record or playback photo-CD.  Meanwhile those of us who
> don't have an ax to grind will have saved thousands using this format.
> 

your money is probably safe, decoding photo CD is not at the top of my list of
priorities.

I will be interested in useing the data for making gray masks etc. This will
require access to the full resolution data.

As a tangent to the Photo CD thread, What has happened on the 'Premier' frount
in the last 6 monthes or so?

~Paul

Newsgroups: rec.photo
From: chang@ecf.toronto.edu (CHANG Rong Fawn Teresa)
Subject: Nikon f401s comments
Organization: ECF, UofT
Date: Sun, 23 Aug 1992 22:40:40 GMT

Does anyone consider Nikon f401s camera a professional one or a P&S or both?
Any (detailed) comments or suggestions are appreciated.  Email is okay too.
From: johno@sdd.hp.com (John Ongtooguk)
Newsgroups: rec.photo
Subject: Re: Photograping Whales [8008s autofocus problem]
Date: 2 Sep 1992 16:11:34 GMT
Organization: Hewlett-Packard, San Diego Division
Distribution: world
NNTP-Posting-Host: hpsdlg10.sdd.hp.com

In article <PHILG.92Sep1181633@zug.ai.mit.edu>, philg@zurich.ai.mit.edu (Philip Greenspun) writes:
|> 
|>    | Nikon autofocus is basically decorative.
|> 
|> 		   -Philip Greenspun
|> 
|> Hold a Minolta 7xi in your hands for two minutes and pan it around a
|> camera shop or other cluttered space.  Then tell me that our Nikons
|> have autofocus.  What they really have is manual focus whereby you put
|> the sensor on top of what you want sharp, push the shutter release
|> halfway, then recompose.  
|> 
|> What Minolta has is true autofocus.  The camera analyzes the scene,
|> taking into account data from multiple sensors, and always (in my
|> limited experience) picks some sensible collection of things to make
|> sharp.

   Thinking back on some of my shots I can't see how the AF system
   would know that I wanted the eyes or whatever in sharp focus,  
   especially when using a long lens up close in a cluttered scene.
   I'm guessing that the Minolta AF is working as a fancy zone
   focusing system most of the time, where adequate depth of field
   improves the odds of 'correct' focusing.
 
   John Ongtooguk (johno@sdd.hp.com)
From: swlodin@rphroy.ph.gmr.com (Steve Lodin)
Newsgroups: rec.photo
Subject: Camcorder Buying Questions
Date: 27 Aug 92 17:28:14 GMT
Organization: GM Research Labs, Warren, MI


Hello Net,

I am contemplating buying a camcorder mail order. I have a couple 
of questions... Here they go:

1. Could someone recommend a respectable mail order house? I have
   had a couple of suggestions, I'd appreciate some more. 

2. I was also warned about the availability or lack thereof of
   US Warranties and Manuals. The model I was interested in, a 
   Sony TR-71, goes for $649 gray market and $819 legit. 
   Obviously everyone does it this way... There were a few articles
   (oops, ads) advertised it for say $799 and I wondered why...
   Any words of wisdom there? Are (some) mail order people THAT
   slimy?

I posted a similar plea in misc.consumers and was advised rec.photo
is the place for such requests. If there is a camcorder or mail order
FAQ's I will appreciate someone emailing or pointing them out to
me. 

Please respond to the address below, do not use 'r'eply.

Thank you in advance,

Spiros 
--
Spiros Triantafyllopoulos                    c23st@kocrsv01.delcoelect.com
Software Technology, Delco Electronics       striantafyll@kosds1.gm.hac.com
GM Hughes Electronics, Kokomo, IN 46904      [A Different Kind of Disclaimer]

Newsgroups: rec.photo
From: yz@broca.acc.virginia.edu 
Subject: Re: For sale: Slide projector
Organization: University of Virginia
Distribution: na
Date: Thu, 27 Aug 1992 21:41:06 GMT

In article <4815@daily-planet.concordia.ca> honna@cs.concordia.ca (SEGEL honna)  
writes:
> Kindermann Automatic 300 (Model 1075) (2 1/4 x 2 1/4)
> 	110V/ 240V; takes CMV bulb; current CMV works
> 	100 mm f/2.8 Projar lens (like new)
> 	20 x 22.5 x 25 cm (w x h x d)
> 	Cords still supple (white vinyl); 12` remote cord
> 	real fake leatherette carrying case 25 x 30 x 45 cm  
> Reply c/o this account.  Best offer.    
I would be interested in buying it. But since my E-Mail isn't set up, is their  
a phone number you can post or you can call me. 
	Yuan 1-(804)-293-4290
thanks.
From: honna@cs.concordia.ca (SEGEL honna)
Newsgroups: rec.photo
Subject: Re: Nodal point on lens.
Date: 2 Sep 92 19:19:21 GMT
Organization: Computer Science, Concordia University, Montreal, Quebec

In article <1992Aug28.041539.1840@cello.hpl.hp.com> jacobson@cello.hpl.hp.com (David Jacobson) writes:
>There are two nodal points.  The rear nodal point is one focal length
>in front of the film place when the lens is foused at infinity.
>
>This is not always possible, since on some lenses the image is
>actually behind the front element.  In that case you can use a macro
>lens to find the point of focus.

How, pray tell?
>
>Another fancier scheme that doesn't depend on knowing the focal length
>is the "nodal slide".  Arrange the lens on a pivoting mini-table.
>(It pivots about a vertical axis.  You are looking down in this diagram.)
By "pivoting mini-table" do you mean something like a Lazy-Susan?
>
>                       ---------------------- mirror
>
>
Should the mirror and slitted screen be plane-parallel?
>
>
>                                lens on table 
>
>
>                        white
>                       ------------ --------------- 
>                                      slit
>
>                                  lamp
>
>Now light will pass through the slit, through the lens, reflect off the
>mirror, and come back onto the white back side of the slit.  When you
>rotate

rotate about the vertical axis, presumably?

>the lens the image will move.  Adjust the distance from the
>pivot of the table to the slit and the position of the lens over the
>pivot until the image of the slit is share and does not move when the
>lens is rotated a little.

This looks suspiciously like I have to adjust Two things: slit-pivot
distance, and lens-pivot relation...Is there an easy algorithm for deciding
which to do first, and how to determine the direction of the adjustment?

I'm not sure what you mean by "until the image of the slit is share"...

Can this whole procedure be simplified so that I can determine my slide-
side lens nodal point while the lens is On the camera body?  A mirror on the
film rails, perhaps, the camera on one of those cheapo flash-brackets
(with the sliding 1/4 - 20 screws); these together on a level tripod
head( such that the bracket's Fixed 1/4 - 20 screw is secured to the
tripod head)?

>  The distance from the pivot to the slit is
>the focal length and the pivot is over the slide-side nodal point.

Flash bracket looks something like this:

_______________________________________                                       
|              ____________________    |  
|   X 	( )   (____________________)   |
|______________________________________|                                        
                                                        _________________ 
 Flash shoe at X; fixed screw at ( ); sliding screw in (_________________).                                       


HS/Michael

-- 
***************************************************************
honna segel
department of computer science
concordia university  *****************************************
From: donl@glass.esd.sgi.com (donl mathis)
Newsgroups: rec.photo
Subject: Re: binocs and camera lenses
Date: 26 Aug 92 17:27:31 GMT
Reply-To: donl@glass.esd.sgi.com (donl mathis)
Organization: Silicon Graphics, Inc., Mountain View, CA, USA


In article <1992Aug25.214013.23287@fig.citib.com>, ghica@fig.citib.com
(Renato [Titanium Cranium] Ghica) writes:
|> 
|> 
|> what is the correlation between specs for binoculars
|> and specs for SLR lenses? Is there any?

Nope.  Sorry.

|> For example a 7 X 35 pair of binocs would give magnification
|> and agle of viewing the same as a XXXmm lense, fYYY ?

You no doubt already know what's going on with the binocular specs --
magnification is 7x, and the objectives are 35mm in diameter.  The 7x
refers to *angular* magnification, i.e. something that's one degree
wide in real life will appear to be seven degrees wide through the
lens.  You can't really talk about the *size* of the image you see
through the binoculars, because it's just floating in space somewhere.
(How big does a nickel look?  Well, it depends on how far away it is.
The nickel doesn't change physical size as it gets farther way, but
it's angular size does change.)

Now, with a camera lens, you're putting the image on film, which gives
you a bit more of a concrete reference to work with, since the film has
a specific size.  If you think about how the image is formed, and pick
up on a couple of significant optical facts, the answers come
relatively easily.

First, you can draw a straight line from any point in the subject,
through the center of the lens, to the place where that point will be
imaged on the film.  This includes lines at an angle to the camera's
straight-ahead view.

Then, you need to consider that the distance between the film and the
optical center of the lens is approximately the focal length.  You can
use the focal length for practical calculations; if you need the
precise distance, use the formula "1/F=1/u+1/v", where F is the focal
length, u is the distance from the lens to the subject, and v is the
distance from the lens to the film.

Given those two facts, you can draw a little triangle and see how it
all works out.  The point of the triangle is in the center of the
lens.  The base is at the film plane, and it's either 24mm wide, or
36mm, or 43mm (the diagonal), or whatever size you choose.  The height
is the focal length.  A little trig and things fall right into place:

	angle of view = 2 * arctan(filmwidth / 2F)

The "F" number has nothing to do with the angle of view.  (Well, it has
a little bit to do with it in view lenses, because of vignetting, but
that's not important right now.)  The value is written most clearly, I
think, as "F/2.8", because that is the formula for the maximum size of
the aperture.  A specific lens can be described as 50/2, for example,
which tells you that the maximum aperture is 25mm in diameter.  2/50
doesn't make as much sense.  F-2 doesn't mean much, either.  So it's
F/2, or f/2, thank you.

|> Does anyone know?

Nope.  Oh, wait -- *you* do!

- donl mathis at Silicon Graphics Computer Systems, Mountain View, CA
donl@sgi.com
Newsgroups: rec.photo
From: rdj@fir18.cray.com (Ralph Jenson)
Subject: Re: Lead-acid 2CR5 adapter for Canon? (was: Canon EOS Rebel at high altitude and Cold - Problems ??)
Originator: rdj@fir18
Organization: Cray Research, Inc.
Date: 27 Aug 92 09:17:50 CDT


In article <BEN_WEN.92Aug25225412@e40-008-9.mit.edu>, ben_wen@athena.mit.edu (Benson Wen) writes:
> In article <1992Aug25.162156.12266@hemlock.cray.com> rdj@fir18.cray.com (Ralph Jenson) writes:
> ...
> Heyyyyyy! a lead acid battery adapter for a 2CR5 battery?  Cool.  Tell
> us more!  Where is this JVB? 
> 

JVB Designs 305/754-7862
PO box 53-0095
Miami, FL 33153.

I have no connections with JVB except as a VERY satisfied customer. I haven't
tried to reach him after the hurricane so...

-Ralph-
-- 
Ralph Jenson                                612/683-5776
UNICOS Software Support                Cray Research Inc
UUCP: ...!uunet!cray!rdj              INET: rdj@cray.com
USnail: 655F Lone Oak Drive MS20         Eagan, MN 55121
Newsgroups: rec.photo