HDTenEightyP/NetNews huggingface dataset:
From: mikec@spider.co.uk (Mike Coren)
Newsgroups: rec.photo
Subject: Re: Questions about everything
Date: 8 Jan 93 16:36:55 GMT
Organization: Spider Systems Limited, Edinburgh, UK.

In article <C0HBsE.F0M@hpwin052.uksr.hp.com> bob@hpwin052.uksr.hp.com (Bob Easton) writes:
>Mike Coren (mikec@spider.co.uk) wrote:
>| 
>| 1)  Why do fast zoom lenses need rediculously wide filters when compared to
>| their slower counterparts?  For example, compare the specs on the Tokina
>..
>| Is there a simple explaination for this, or is this one of the subtleties
>| of modern computer-aided optical design?
>
>I'll fall for this one :) Bigger aperture = bigger hole. Bigger hole
>needs more glass to fill it with light. Bigger glass needs bigger
>filter.
>

Thanks.  I had figured that much out myself.  The key word in the original
question is "rediculously".  The part of the post which you omitted is the
main question, which brought up three points about the Tokina 28-70mm f/2.8:

	1) 70mm f/2.8 only *needs* an opening of 25mm diameter

	2) At the 28mm end, to get the spec'd field of view (I think it
	   was around 77 degrees), a hollow tube of the same length as
	   this lens would need an opening of over 100mm diameter

	3) The lens actually uses a 72 (or was it 77?) mm filter, which
	   seems completely unrelated to either of the other numbers.

>| 
>| 4)  Does the light in the refrigerator turn off when you close the door?
>
>Only if the fridge is turned on
>

So are you saying that if the fridge is turned off, the light will stay on? ;-)


>| 8)  What is the air speed velocity of an unlaiden swallow?
>
>From my throat to my oesophagus, about 1 sec. Can't get the tape measure 
>down there to measure the distance tho.
>

Now THAT'S gross.


>Bob

Mike

-- 
Michael D. Coren, Electrical Engineer             mikec@spider.co.uk
Telecommunications Techniques Corporation, Germantown, Maryland, USA.
Temporarily at Spider Systems Limited, Edinburgh, Scotland, UK.
From: ak873@cleveland.Freenet.Edu (Michael Sapienza)
Newsgroups: rec.photo
Subject: Info needed on Canon 100-300 USM
Date: 13 Jan 93 01:47:19 GMT
Reply-To: ak873@cleveland.Freenet.Edu (Michael Sapienza)
Organization: Case Western Reserve University, Cleveland, OH (USA)
NNTP-Posting-Host: slc10.ins.cwru.edu



I am looking for information on the Canon 100-300 USM lens.  I am looking
for dimensions, i.e. how does it compare to the 28-80 USM.  Also, any
recommendations would be appreciated.  I am planning a trip to Alaska, and
want to get those "close-up" shots of all the wildlife!  By the way, I 
have an Elan, if that matters.

Thanks,
Mike
-- 
+---------------------+-----------------------------+-------------------------+
| Michael A. Sapienza | ak873@cleveland.freenet.edu | AmericaOnline: Sapienza |
|                     | ac860@yfn.ysu.edu           | sapienza@aol.com        |
+---------------------+-----------------------------+-------------------------+
From: russell@Apple.COM (Russell Williams)
Newsgroups: rec.photo
Subject: Re: IBM vs. Mac for stock business
Date: 8 Jan 93 17:11:59 GMT
Organization: Apple Computer Inc, Cupertino, CA

In article <93007.200852U42075@uicvm.uic.edu> U42075@uicvm.uic.edu (Theodore Stresen-Reuter) writes:
>Hello,
>
>I would like to start a discussion addressing the pros and cons of IBM
>vs. Macintosh as a multipurpose machine for an independent photographer.

Both systems probably have software packages available for running a
photo business, or you can buy a cheap database and roll your own. If
you're going to buy a package solution for the business part, check
into the packages available first, and expect to pay significant $$$.
There are also packages available for running stock photo businesses on
the Mac (and probably on the PC as well). Packages such as Photo Memory
for the Mac keep descriptions along with thumbnail images in a database
and allow you to search for them by description and view the (miniature,
low-resolution) images easily. The "real" images stay on film.

If you're going to do full-resolution image manipulation, get the
fastest machine you can (486 or 68040) and *at least* 32 MB of RAM --
if you can't afford 64MB now, at least make sure the machine is 
expandable to that. Unless you input from Photo-CD, you're not going to
have a way to get high quality, high-resolution full color images into the
machine for a total cost of $3000. Right now, the fastest PC (486) machines are
somewhat cheaper than the fastest Macs (68040/Quadra), but check again
next month -- everybody brings out new machines every month, and the
differences in price between Macs and PCs (especially IBMs) are small
to non-existent in certain market segments. For photo manipulation, you'll
want 24 bit color, and probably a monitor larger than 14"; in a
(monetary) pinch, a 13" monitor with 16 bit color will do. Somehow I 
doubt that you'll be able to get a fast machine with 32MB, CD-ROM drive,
19" monitor and 24 bit color for under $3K. 

If you're going to store images, you'll 
either need to have them on CD-ROM on Photo-CD (and thus need a CD-ROM
drive), or store low-resolution versions on hard disk; expect to need
a huge hard disk for any significant number of images bigger than 
thumbnails. The Mac has better software for using Photo-CDs --
practically any program that can read graphics can open Photo-CD files..

The Mac has been the established machine in the photo manipulation biz
for some years; you'll find more people with experience on it, and
more software, though the biggest titles (e.g. Photoshop) have now
been ported to Windows.  Every study I've ever seen shows the Mac to
take less time to learn -- both the system and each new application.
Go visit some businesses that do this kind of thing, and watch how they work.

My bias? Just check the "Organization" line in the header.
-- 
Russell Williams
Not speaking for Apple Computer
Newsgroups: rec.photo
From: hamm@weejordy.physics.mun.ca (Craig Hamm (Evil Spock))
Subject: Digital Color article
Organization: Ocean Sciences Centre
Date: Wed, 6 Jan 1993 18:44:24 GMT

	The December 'Physics Today' has been devoted to 'Digital Color'.
	Looks interesting!

	(hope this wasn't posted before! I just received my issue.)

-- 
  Craig Hamm, Memorial University,|   
  Newfoundland, Ocean Acoustics   |
  Canada                          |
  ________________________________|

Newsgroups: rec.photo
From: jacobson@cello.hpl.hp.com (David Jacobson)
Subject: Re: 430EZ question
Date: Tue, 12 Jan 1993 16:54:25 GMT
Organization: Hewlett-Packard Laboratories

In article <1993Jan12.012114.29757@informix.com> neilw@informix.com (Neil Williams) writes:
>I guess I don't understand the problem.  The 430EZ tells you
>*before* the picture is taken whether or not the scene will
>be correctly exposed.  If you can know beforehand, why would
>you prefer to know after the fact?
>
>I find the ATTL particularly useful when trying bounce flash
>with high ceilings - if you get an incorrect exposure warning,
>just flip the flash head down and shoot direct.
>
>--Neil

I can't answer this question regarding Canon equipment, since I'm a
Nikon user.  But here is a trick that works on the Nikon SB-24 with
8008, and it might work here to find out if you will have enough
light before actually shooting a frame.

I just slide the main mode switch from TTL to AUTO, then press the
test button.  If the ready blinks after the flash, there was not
enough light.  (Nikon systems foolishly blink the ready light on
insufficient light instead of having a separate "there was enough
light" indicator.)  The AUTO mode uses the sensor on the front of the
flash instead of the off-the-film sensor, but that is OK as long as
I'm not using any filters, etc.  The SB-24 reads the film speed and
f-stop from the camera body, so knows the correct threshold for the
sensor.  (There is one glitch: the SB-24 does not read the f-stop in
AUTO but but inherits it from the last reading in TTL mode.  This
causes several minor invconveniences.  Maybe Nikon fixed this in the
SB-25.)

  -- David Jacobson
From: richard.vernick@satalink.com (Richard Vernick)
Newsgroups: rec.photo
Subject: Re: Nikon F3 quirk?
Date: 6 Jan 93 00:23:00 GMT
Reply-To: richard.vernick@satalink.com (Richard Vernick)
Organization: Datamax/Satalink Connection * Ivyland, PA (215) 443-9434

TO: poole@bnr.ca

TP>Just after loading a new roll of film the shutter
TP>speed will be set to 1/80 until the frame counter
TP>reaches 1. Don't ask me why.

Thomas,

It happened to be the first picture I ever got published but, this is
why: At 5:00am the fire engines went screaming by my house. I was 15 and
just bought my brand new Nikon FE. I grabbed the camera, a roll of film,
my pants and ran. It was a barn engoulfed (sp?) in flames. Out of breath
and running on pure adrenylin, I loaded the camera with the lens cap on.
When I fired the shutter, it stayed open on the the automatic setting. I
turned the shutter to the 1/1000th setting to rush the load. Not
remembering, I left the shutter at 1/1000th. I thought I had some great
shots but, they turned out to be completely underexposed. I stayed home
from school that day to develop and print something. There happed to be
1 shot, a siloette of the barn and flames. That picture was published on
the front page of our local paper.

If the FE would have stayed on 1/80th until the film was loaded, I would
have never underexposed that roll of film and I could be shooting for
Time.

Rich
---
 . KingQWK 1.05 . Parking is such street sorrow. -- Mario Andretti                           
                                    
From: peterd@hpgrla.gr.hp.com (Peter Davidoff)
Date: Fri, 8 Jan 1993 17:26:47 GMT
Subject: Re: Shirt Pocket Cameras
Organization: Hewlett-Packard, Greeley, CO
Newsgroups: rec.photo

Steve:

Recently I read an article about a 19th century vogue:  cameras in a hat.
Yep.  They mounted the entire box and plate in the hat, dropped from the
front brim a range finder, and over the ear, on a cord, was the shutter
trip.

Seems like a great alternative to the pocket camera, eh?  :)


Peter
Newsgroups: rec.photo
From: duli@boulder.Colorado.EDU (Li Du)
Subject: Re: Fuji GW670 tests?
Organization: University of Colorado, Boulder
Date: Mon, 11 Jan 1993 06:14:36 GMT

In article <BSON.93Jan10220912> bson@gnu.ai.mit.edu (Jan Brittenson) writes:
>   I've used the GSW-690III (65/5.6 lens, the new III model) for about
>three months now. I can notice a slight fall-off at the corners of
>Velvia shot with it, but it's definitely not a stop.  Maybe 1/3 to 1/2
>stop at wide open. In fact, I hadn't even noticed (or thought about)
>it before I read your post.
>
	From what I have read, it seems that it's not uncommon for a 6x7 
	or a 6x9 lens to have about or more than one stop stop light fall-
	off at the corners(@f/5.6). Whether it is obvious or bothersome on 
	film depends upon the scene, lighting, exposure and type of film used. 
	I found in my experience that the light fall-off of my Fuji 690II 
	to be more noticeable on Kodachrome film than on Fuji Velvia, which 
	is not all that surprising, because I under-expose Kodachrome while
	over-expose Velvia. I also found that polarizing would make light
	fall-off more visible. Maybe I shouldn't say that all my slides
	have more than one-stop fall-off at cornors. But light fall-off
	was very noticeable in the comparison tests I mentioned in my
	original post, and I measured the amount of fall-off using spot
	metering and saw slightly over one-stop fall-ff at very corners.

---------------------------------
 Li Du | duli@prony.colorado.edu
---------------------------------
From: sog@craycos.com (Steve Gombosi)
Newsgroups: rec.photo
Subject: Re: Questions about everything
Date: 5 Jan 93 16:25:28 GMT
Organization: Cray Computer Corporation

In article <1993Jan5.114632.29209@spider.co.uk> mikec@spider.co.uk (Mike Coren) writes:
>3)  Why doesn't exposure value take film speed into account?  An EV by
>itself seems useless if you don't know what film speed is being used.  Is
>there something like an EV-ASA product that's commonly used?

Ummm...because EV is an EXPOSURE value, not an ILLUMINATION value.
EV gives you a convenient method for referring to all combinations of
shutter speed and aperture that produce the same *exposure*. 
Actually, EV is used pretty sloppily these days - a *lot* of folks say
"EV" when they are referring to an absolute illumination level. In this
case, they're really talking about "EV at ISO 100".

>4)  Does the light in the refrigerator turn off when you close the door?

Mine stays off all the time (the switch is broken).

>5)  Guide numbers on flashes are typically given for 100 speed film.  If I'm
>using 400 speed film, should the guide number be quadrupled, or only doubled,
>since light intensity decreases with the square of the distance, or something
>completely different?  (Actually, I think I know the answer to this one based
>on EV's, but humor me anyway).

Doubled.

>7)  Are UV filters for black & white only?  I read where this guy was fairly
>adamant that UV filters are only for B&W, and you should use a skylight filter
>for color.

Depends on whether or not you want the slight warming effect of the skylight.

>8)  What is the air speed velocity of an unlaiden swallow?

About EV 12.

Steve
From: robert@sys.sweden.dg.com (Robert Claeson)
Newsgroups: rec.photo
Subject: Re: 81A, 81B, & 82A filters: What are they for?
Date: 8 Jan 93 08:09:09 GMT
Organization: Data General AB, Akalla, Sweden

In article <1992Dec31.102656.1@pearl.tufts.edu>, rsmith@pearl.tufts.edu writes:

> I've got three filters that I got years ago.  They were originally lying around
> with some unused equipment or something that my father found, so I don't know
> what they're for.  One is an 82A (light bluish-green color), the others are
> 81A and 81B (brownish-yellow).  What are these things used for?  Thanks for
> any information.

If my memory serves me right, the 82A is used to adjust the color
temperature slightly towards a cooler image tone. The 81 series is for
adjusting towards a warmer tone with color films. The 81A is a very usable
filter. The 81B is stronger, and combined, they give a very pronounced
effect, similar to that of an 81E filter. Try the 81A filter for portraits.

-- 
--------------------- This mass of gibberish came from ---------------------
         ____
        |    |               Robert Claeson
        |    |               Data General AB
 _______|____|_              Box 28
|    |    _    |_____        S-164 93 KISTA
|_/\ |   / \   |     |       Sweden
| \/ |   \_/   |   . |
|    |    |    |_____|       robert@sys.sweden.dg.com
|____|_________|-
Newsgroups: rec.photo
From: glp@fig.citib.com (Greg Parkinson)
Subject: Nikon Lenses
Originator: glp@merlin
Organization: Citibank IBISM
Date: Wed, 6 Jan 1993 15:19:49 GMT


I just inherited a case full of Nikon equipment - 
an FE, FE2, and a bunch of lenses.  I've been trying
to get an idea of value by looking up prices in
Shutterbug, but I'm not sure of the designations.

I know the lenses are not AF, but I don't know the
difference between AI and AI/S and there doesn't
seem to be any indication on the lenses themselves.

Any advice?

Thanks in advance.
-- 
Greg Parkinson                  Phone: 212-657-7814  Fax: 212-825-8607
Citibank,111 Wall Street        E-Mail: glp@fig.citib.com
New York, New York  10043
The opinions expressed are my own and not those of the big 'ol bank.
Newsgroups: rec.photo
Subject: multiple exposures
From: jenny@gphs.vuw.ac.nz (Jenny Rollo)
Date: Sun, 10 Jan 1993 22:39:28 GMT
Organization: Institute of Geophysics, Victoria University of Wellington, NZ

I have been reading the May 1992 issue of "The National Geographic" magazine, and
have been marvelling at the photography for the article entitles "The Great Eclipse".  On the first pages of this article, there is a multiple exposure photo from start to finish of the total solar eclipse which took place on July 11th 1991.  I am very interested in starting to take some multi-exposure shots myself and wonder if someone would be able to help me with my queries.  Firstly in this photo there are obviously 28 different exposures on the one frame.  Each frame is well exposed and my question is


 what sort of exposure time might be used for this type of photograph?  It is taken at nightfall and I can't see (I know nothing about this!) how you can get a long enough exposure without showing the Earth's movement and without overexposing the observatory. also shown in the picture.  My other query is that a person is standing on top of the observatory, arms outsretched.  How can he have registered clearly on the film, surely he would have had to stand in this pose for some time.  Sorry to be so ignoran


t, but I can't see with my lack of knowledge in these areas how it was done.  I hope someone can enlighten me on this problem.

Thanks in advance.

Jenny Rollo.

jenny@gphs.vuw.ac.nz 
Newsgroups: rec.photo
From: bob@hpwin052.uksr.hp.com (Bob Easton)
Subject: Re: Questions about everything
Date: Thu, 7 Jan 1993 10:29:01 GMT
Organization: the HP UK Response Centre
X-Newsreader: TIN [version 1.1.4 PL6]

Mike Coren (mikec@spider.co.uk) wrote:
| 
| 1)  Why do fast zoom lenses need rediculously wide filters when compared to
| their slower counterparts?  For example, compare the specs on the Tokina
..
| Is there a simple explaination for this, or is this one of the subtleties
| of modern computer-aided optical design?

I'll fall for this one :) Bigger aperture = bigger hole. Bigger hole
needs more glass to fill it with light. Bigger glass needs bigger
filter.

| 
| 2)  Why does film speed (ASA) increment in 1/3 stops, while shutters and
| apertures typically increment in 1/2 stops or whole stops?

Perhaps it was easier to accurately subdivide a stop in film manufacture 
than it was in the mechanical control of lenses and shutters, so the 1/3
stop subdivisions in (logarithmic) film speeds came first. Half stop
increments in user set shutter speeds are a product of new electronic cameras,
though manual lenses had 1/2 stop clickstops earlier than that. I
suppose it made more sense to subdivide speeds to match the pre-existing
1/2 stop aperture subdivisions?
| 
| 4)  Does the light in the refrigerator turn off when you close the door?

Only if the fridge is turned on

| 
| 5)  Guide numbers on flashes are typically given for 100 speed film.  If I'm
| using 400 speed film, should the guide number be quadrupled, or only doubled,
| since light intensity decreases with the square of the distance, or something
| completely different?  (Actually, I think I know the answer to this one based
| on EV's, but humor me anyway).

Doubled (ie 2 stops more range) (ie for GN30 at 100ASA, f/16 gives you
2m range; at 200ASA it gives you 2.8m and at 400ASA it gives you 4m -
recognize the scale?)
| 
| 8)  What is the air speed velocity of an unlaiden swallow?

From my throat to my oesophagus, about 1 sec. Can't get the tape measure 
down there to measure the distance tho.

Bob
From: tim@nijinsky.ipac.caltech.edu (Tim Conrow)
Newsgroups: rec.photo
Subject: Re: Canon 10s Vs Nikon N90, Which one?
Date: 5 Jan 93 10:51:26
Organization: California Institute of Technology
	<1992Dec29.052659.5274@jarvis.csri.toronto.edu>
	<TIM.93Jan4123851@nijinsky.ipac.caltech.edu>
	<1993Jan5.152812.11043@spider.co.uk>
NNTP-Posting-Host: nijinsky.ipac.caltech.edu
In-reply-to: mikec@spider.co.uk's message of 5 Jan 93 15:28:12 GMT

In article <1993Jan5.152812.11043@spider.co.uk> mikec@spider.co.uk (Mike Coren) writes:
   In article <TIM.93Jan4123851@nijinsky.ipac.caltech.edu> tim@nijinsky.ipac.caltech.edu (Tim Conrow) writes:
   >In <C00D8z.Mw3@jrd.dec.com> diamond@jit533.jit.dec.com (Norman Diamond) writes:
   >
   >>In article <1992Dec28.164753.21867@research.nj.nec.com> lds@ccrl.nj.nec.com (Duan-Shin Lee) writes:
   >
   >>>I think the screen with MF aid that you talk about is the microprism screen. 
   >>>Can you point out some evidence that this screen messes up the metering
   >>>system?
   >
   >>On an F-801, none that I know of.  On an F-801s, the manual says that the
   >>microprism screen for F-801 can be used in F-801s but that spot metering is
   >>no longer usable.  I don't know how badly it messes up spot metering.  I wish
   >>I could get microprism around the center spot rather than in it, and also
   >>have the grid outside of that.  Where oh where are the third parties....
   >
   >The micro-prism focussing aid certainly DOES mess up spot metering on the
   >8008s. I know this by experimentation with my own equipment. there is also
   >a warning to this affect in the manual. I am not aware of any problems
   >with other metering modes.
   >

   I don't know much about interchangeable screens or Nikons in general (I'm a
   Canon man), but I would imagine that the amount of "messing up" caused by
   the microprism screen on the spot metering would be constant.  All you would
   need to do is take some test slides with lots of bracketing, figure out how
   much more or less exposure you need from what the meter tells you, and just
   apply that correction each time.  Or am I missing something?

   >-- Tim

   Mike

   -- 
   Michael D. Coren, Electrical Engineer             mikec@spider.co.uk
   Telecommunications Techniques Corporation, Germantown, Maryland, USA.
   Temporarily at Spider Systems Limited, Edinburgh, Scotland, UK.


As a netter pointed out to me while I was investigating this, microprism
focusing aids tend to go black when the lens speed drops too low. For
non-constant aperture zooms this alters the response of the spot meter.
For constant aperture lenses, perhaps your conjecture is correct, I don't
know, I didn't check.

-- Tim
From: tnelson@ncrcan.Canada.NCR.CA (Tim Nelson)
Newsgroups: rec.photo
Subject: Re: How to become a freelance photojournalist?
Date: 6 Jan 93 17:01:24 GMT
Distribution: na
Organization: NCR Canada Ltd. Mississauga, Ontario

In article <wkmpph-050193074613@norie_sato.isc.rit.edu> wkmpph@ritvax.isc.rit.edu (W. Keith McManus) writes:
:In article <15224@ncrcan.Canada.NCR.CA>, I wrote:
:> 
:> I volunteered to do some photography for a couple organizations, who would
:> like their events photographed and published in the local newspapers, but
:> I was wondering how I could get a photo-journalists papers, so that I can
:> be out taking pictures, and don't have to worry that anyone will bother me
:> and tell me that I have to put away my camera.  (ie freedom of the press
:> and all that stuff)
:> 
:> The organizations who wanted me to do this don't have any idea where I
:> should start.
:> 
:> Do you?
:
:Some questions first...
:
:What are the organizations for which you have been photographing?
:
:At what types of events have you been told to put your camera away?

I was photographing a booth set up for the cancer society, to put in the
local paper, when a police man told me that unless I had papers indicating
that I was taking pictures for a newspaper or magazine, that I must put
away my camera.  After some discussion, the problem was taken care of, but
I just don't want to have to waste my time on that again.

So, what I really need to find out is whether there is some sort of
identification for freelance photographers which shows that they are
taking pictures for journalistic reasons, similar to press passes and
press id which are usually worn by tv folks.

I don't have problems otherwise, it is just to keep me from having to explain
what I am doing all the time to someone who is trying to force me to put
away my camera, then giving me the ok after 30 minutes discussion or more.

-- 
Tim.Nelson@Canada.NCR.CA
NCR Canada +1 416 819 4112