HDTenEightyP/NetNews huggingface dataset:
From: john@earlj.b11.ingr.COM (John H. Earl)
Subject: Polarizing Filters
Reply-To: john@earlj.b11.ingr.COM
Organization: Intergraph Corporation, Huntsville, AL.
Date: Thu, 3 Sep 1992 21:30:53 GMT

I went into a camera store the other day to buy a polarizing filter.  The
clerk asked if I need a linear or circular filter.  This was news to me.
Apparently autofocus cameras need a circular filter.  I don't have an AF
camera but I'm now curious to know:

	1) Why do AF cameras need a special type?

	2) How does a circular polarizer work?  With a linear filter, the
	orientation of the filter determines the amount of polarization
	(or perhaps direction is more accurate).  I can't figure out how
	the circular filter could be oriented.

-- 
            ****************************************************
            *    Intergraph        |       John H. Earl        *
            * Systems Product      |      (205) 730-6536       *
            *    Marketing         |  john@earlj.b11.ingr.COM  *
            *  Huntsville, AL      |     Mail Stop: CR1102     *
            ****************************************************

Newsgroups: rec.photo
From: dougb@comm.mot.com (Doug Bank)
Subject: Re: Nikon 35-105 AF lens
Reply-To: dougb@ecs.comm.mot.com
Organization: Motorola Land Mobile Products Sector
Distribution: na
Date: Fri, 4 Sep 1992 13:32:10 GMT

In article <1992Sep4.021025.17689@cbnewsl.cb.att.com>, 
|> I do have one complaint about the lens, however: unlike my 80-200
|> Nikkor, when I change the focal length I have to refocus. With
|> separate focus and zoom collars, this is pretty inconvenient. Also,
|> a lot of pictures are scenics where focus is at infinity, and on all
|> my other lenses I can just turn the fucusing collar completely clockwise
|> and be locked in at infinity very quickly; that doesn't work with the
|> 35-105 AF. I am using the lens on a non-AF camera (FE2), and I realize
|> that if I had (and used) AF I wouldn't have this complaint (but I might
|> have other complaints when I took pictures of whales :-).
|> 
|> Does anyone know if the older AIS 35-105 works the same way? If it
|> works like th 80-200, I might consider taking a loss and trading the
|> lens for a used AIS version.

Do you have the version that close-focuses at 105mm or at 35mm?
I have the older AF lens (close focuses at 105mm) and it definitely
does NOT have this problem.  Perhaps you should have it checked out.
It doesn't sound like a proper, working Nikon lens to me.

-- 
Doug Bank                       Private Systems Division
dougb@ecs.comm.mot.com          Motorola Communications Sector
dougb@nwu.edu                   Schaumburg, Illinois
dougb@casbah.acns.nwu.edu       708-576-8207                    
From: leonglaw@hpsgm2.sgp.hp.com (Lawrence LEONG)
Date: Thu, 3 Sep 1992 15:43:09 GMT
Subject: Re: Popping slides and curved field lenses
Organization: HP Singapore
Newsgroups: rec.photo

In rec.photo, frank@truevision.com (Frank Loffel) writes:

|Here come a few really tough questions:
|
|Why do slides pop when projected (heated up)?
|Is there a glassless mount that prevents popping?
|Are curved field lenses designed to correct curvature before or after popping
|occurs?
|When is the slide more curved: Before or after popping?
|
|I know that mounting a slide between glass will provide good center to edge
|sharpness with a flat field lens. However, I believe that it's not a good
|idea to mount originals between glass, because they a) get baked quite a bit
|and b) might deteriorate because of lack of air. The alternative is to dupe
|the originals and project the dupe using glass mounts. Pretty complicated.
|
[ stuff about glass mounts deleted]

There is differential expansion caused by the bulb, so you get an effect 
somewhat like a bimetallic strip.


I've thought about a possible solution.  If you place a gold coated glass
slide between the slide and bulb, would this dissipate some heat.  The gold
coating would have to be real thin, like the thickness used for specimen
preparation in electron microscopy.  There might be a warmer cast to the
light, though.

Anyone with the facilities to verify this?

lawrence
From: sog@craycos.com (Steve Gombosi)
Newsgroups: rec.photo
Subject: Re: Inrared Photog + Spider Webs
Date: 31 Aug 92 20:53:54 GMT
Distribution: usa
Organization: Cray Computer Corporation

In article <1992Aug31.174351.26951@cbnewsj.cb.att.com> rdb1@cbnewsj.cb.att.com (ronald.j.deblock..jr) writes:
>I believe that the flower patterns in spider webs show up at ultraviolet
>and not infrared.  This is from a documentary  I saw on PBS a few months
>ago.
>
>Makes sense, if you think about it.  Bees and other insects can see
>ultraviolet.
>
>The show also explained that spiders will change the patterns every
>few days.  The theory is that some bees get caught and manage to escape
>and somehow warn the other bees to stay away.  A new pattern fooled the
>bees into thinking it was a different "flower".  Amazing.
>
>Now, where do I buy ultraviolet film?

Film is easy. Lenses are a different matter...
Photographic emulsions are quite sensitive to UV, unfortunately most
optical glass is opaque through a lot of the UV range.  Quartz lenses
(like the UV-Sonnar) are *extremely* expensive ($10K - $15K, the last time I
looked).

Steve
From: djmeyer@austin.ibm.com
Newsgroups: rec.photo
Subject: Looking for Info on 21-35/3.5 zoom
Date: 31 Aug 92 19:14:35 GMT
Organization: IBM Austin
Originator: djmeyer@djmeyer2.austin.ibm.com


Does anybody have any first-hand information on the Sigma 21-35
wide-angle zoom.  

I'm looking for a wide-angle zoom for my EOS 620 and the Canon version
is out of my price range.

Thanks.
Newsgroups: rec.photo
From: Dag Asheim <dash>
Subject: Re: Since when has programming been free? (was Re: Time to boycott
        Photo CD
Reply-To: Dag Asheim <dash@ifi.uio.no>
Organization: University of Oslo, Norway
        <glcnc4@dixie.com><FRIEDMAN.92Aug29214928@nutrim
        <FRIEDMAN.92Sep1184721@nutrimat.gnu.ai.mit.edu>
        <1992Sep2.071820.4483@dmc.com>
Date: Wed, 2 Sep 1992 13:37:24 GMT
Originator: dash@gyda.ifi.uio.no

>>>If a programmer doesn't like the way patents affect his freedom, he's
>>>welcome to find a career more suitable to his ethical/political standards.
>>
>>    Once upon a time, programming was such a career.  Why should we have to
>> throw it away?

>I beg your pardon, but programming has NEVER been such a career.  It has
>ALWAYS cost money, until recently LOTS of money, to indulge in a programming
>career.
>
>[stuff deleted]
>
>I think the GNU tools make the world a better and easier place to
>develop software in (well, sometimes, anyway).  But its tough to make a
>living relying on the kindness of strangers.  Which IMHO is what the GNU
>effort has to do.

The point is not really about money, it is about freedom.  It is unfortunate
that this discusion takes place in gnu.misc.discuss, because this isn't a
GNU issue (directly), it is a LPF issue.  GNU wants you to make your
software freely redistributible, and serves as an example of how programmers
could make a living even so.  LPF (League for Programming Freedom)
just want to make sure we have a free market were everybody has equal
chance to develop software.  Patents (at least the way it works in the US
today) works against this free market by giving inventors a monopoly.

All your arguments goes against GNU, and not LPF.  I suggest you try
to find out more about LPF, and why they think patents and interface
copyrigths is a bad thing.

>In short, you can do anything you want to with YOUR money and time, but you
>CAN'T do anything with MINE.

If I get a patent, you can't use the same technique without a lisence
from me.  It seems you agree that patents is a bad thing after all?

Dag Asheim					dash@ifi.uio.no
Department of Informatics
University of Oslo, Norway
Newsgroups: rec.photo
From: siddhart@cs.utk.edu (Siddharthan Ramachandramurthi)
Newsgroups: rec.photo
Subject: Question on Reversible Photo Mounting
Keywords: photo, mounting, adhesive
Date: 28 Aug 92 14:19:51 GMT
Reply-To: siddhart@cs.utk.edu (Siddharthan Ramachandramurthi)
Organization: Computer Science Dept, University of Tennessee, Knoxville
NNTP-Posting-Host: mordred.cs.utk.edu

Hi folks,
I would like to display some color enlargements by mounting them on 
acid-free Fome-Cor, without any matting. I might use shrink-wrap for protection.
The print size is 8x10. The board size would be about 16x20.
 
I don't know what adhesive to use.
Here's what I'm looking for:

- acid-free adhesive
- should be usable for mounting an 8x10 print to Foam-Cor board
- should be removable easily without any damage to the mount board or the print
- price and availability are important too

One candidate is the Clear Mylar Mounting Corners 
from Light Impressions and also from University Products.
Unfortunately, that product seems to be a permanent adhesive.

Any suggestions?

Please e-mail your responses to me.
Thanks in advance.
-- 
Siddharthan Ramachandramurthi   |    
Department of Computer Science  |    
The University of Tennessee     |   
Knoxville, TN 37996-1301, USA   |  Internet: siddhart@cs.utk.edu
From: donl@glass.esd.sgi.com (donl mathis)
Newsgroups: rec.photo
Subject: Re: T-Max films
Date: 1 Sep 92 22:16:28 GMT
Reply-To: donl@glass.esd.sgi.com (donl mathis)
Organization: Silicon Graphics, Inc., Mountain View, CA, USA


In article <n0897t@ofa123.fidonet.org>, Rick.Ellis@ofa123.fidonet.org writes:
|> On <Aug 31 13:55> Robert Feltman writes:
|> 
|>  RF> I have found T-Max 100 to be as forgiving in HC110 (B) as is Tri-X. The
|>  RF> major difference for me has been a rather short N-1 dev. time.
Otherwise
|>  RF> I have found T-Max 100 to be very controllable.
|> 
|> Could the N-1 time be lengthened with a more dilute solution?

It could, but T-Max seems to need a lot of developer energy, and if it
doesn't get enough, the highlight contrast begins to fall off.  I found
noticeable highlight mush with T-Max developer at any dilution greater
than 1:4 -- definitely noticeable at 1:7, and attrocious at 1:15.  I don't
know what happens with other developers.

- donl mathis at Silicon Graphics Computer Systems, Mountain View, CA
donl@sgi.com

The purpose of a windowing system is to make your screen as messy as your desk.
Newsgroups: rec.photo
From: zrepachol@cc.curtin.edu.au (Paul Repacholi)
Subject: Flashes and auto-everything
Organization: Curtin University of Technology
Date: Tue, 1 Sep 1992 08:33:09 GMT

In article <1992Aug31.020639.10599@jarvis.csri.toronto.edu>, acs@csri.toronto.edu (Alvin Chia-Hua Shih) writes:
> In <1992Aug31.065410.1@cc.curtin.edu.au> zrepachol@cc.curtin.edu.au (Paul Repacholi) writes:
> 
> This is true.  However, you are talking about an ATTL preflash.  However,
> I was talking about manual mode, which does not produce a preflash.
> Given that the Omni Bounce supposedly costs 2-1/2 stops of light, I was
> planning to divide the suggested flash-to-subject distance by 3 in
> relative darkness, and by 2 in the presence of some ambient light.
> (Was I being naive?)
> 
I was unsure if you where refering to the flash or the body or both  WRT
'manual'. I assumed flash only, hence the body will use the flash exposure info.
Or so I thought. I have just switched from a 420ez to a 430ez and am still
sorting out its tricks. In manual, there is NO preflash, but the body still
sets its idea of what the exposure should be.


> What flash diffusers/filters do you use on your flash?  How are they
> mounted?  Do you have a special clip to hold filters?
Back of a Kodak gray card for a diffuser, occasionaly a polerizer.
By hand. Or a special 9 year old, 4' high patented filter holder. :-)


> 
> Most importantly, are you a happy flash photographer?  If so, please
> share your technique!  (Eg. do you fiddle with flash exp. comp. when
> you are photographing someone wearing dark clothes, and by how much,
> etc.?)
> 

Not realy. The modern all singing-dancing stuff usualy is good for shoot and
point, no thinking stuff. But noone seems to have concidered the overall
senario. IE, when I first used a Metz 402, it made shooting a little easier,
but printing was *MUCH* harder. The 404 was no better, but its batteries
lasted longer... The TTL and ATTL automagic stuff adds several layers of extra
uncertainty to what happens between the measurement and what the user is told.
Worse, it's not documented in detail, so you can know when the numbers will be
massaged, or the flash change from fill-flash to direct-flash.

Why can't we have a GN mode for the flashes? The body can read the focus
from the lens, and set the appature. No notice of light/dark subject etc,
thats the users problem, BUT he does have a known starting point. 

My favorite was the old Nikor GN lens, but I was lucky enough to have a sharpish
one :-)

~Paul
From: ark@alice.att.com (Andrew Koenig)
Newsgroups: rec.photo
Subject: Re: Since when has programming been free? (was Re: Time to boycott Photo CD
Date: 3 Sep 92 00:56:19 GMT
Article-I.D.: alice.23621
Reply-To: ark@alice.UUCP ()
Organization: AT&T Bell Laboratories, Murray Hill NJ

In article <CMM.0.90.2.715441044.dash@gyda.ifi.uio.no> Dag Asheim <dash@ifi.uio.no> writes:

> The point is not really about money, it is about freedom.  It is unfortunate
> that this discusion takes place in gnu.misc.discuss, because this isn't a
> GNU issue (directly), it is a LPF issue.

Either way, it is not a photographic issue.  Please take this discussion
out of rec.photo.

-- 
				--Andrew Koenig
				  ark@europa.att.com
Newsgroups: rec.photo
From: steve@oceania.com (Steve Dakin)
Subject: Re: Recommend slide labelling program?
Reply-To: steve@oceania.com
Organization: Oceania Health Care Systems
Date: Wed, 2 Sep 1992 21:50:41 GMT

In article <1992Sep1.172634.19221@athena.mit.edu> smcguire@eagle.mit.edu (Scott  
McGuire) writes:
> Can anyone recommend a program for labelling/cataloging slides that runs on
> the Macintosh?

The information in this post is from a floppy disk I ordered from Popular  
Photography which lists computer/photography product sources.

For the Mac, they only list one labelling program (and I am assuming it is for  
slides -- no guarantee):


Product:   Lableware                       Price:not specified
Category:  Labeling                        Platform: P M
Description:

Company:  Multiplex Display Fixture Company
Address:  1555 Larkin Williams Rd.
          Fenton, MO  63026
Phone #:  (800) 325-3350


platforms are: M = Macintosh, P = IBM PC.

There was about a dozen others that ran only on the PC.  I ommitted them since  
the original poster was asking specifically about Mac software.

Cheers,

Steve
-- 
    Steve Dakin                      Oceania Health Care Systems 
 steve@oceania.com (NeXT mail)       Palo Alto, CA (415) 322-0127
 jester@oceania.com                  "That one deserves a...WOW!"
Newsgroups: rec.photo
From: weinstoc@sei.cmu.edu (Chuck Weinstock)
Subject: Canon F-1 Questions
Organization: The Software Engineering Institute
Date: Tue, 25 Aug 1992 18:26:06 GMT


I wonder if any of the regular readers of rec.photo are in a position to help
me?  I have a Canon F-1 (newer version) with the AE head.  I find that it is
so heavy that I don't enjoy taking it on trips.  I'm not a serious
photographer, and the F-1 is more camera than I need.  So I'm thinking of
selling it (and some lenses) and purchasing a newer, lighter, camera.  Here
are my questions:

1. What is a reasonable price to ask for the F-1 with the AE head?
2. What is a reasonable price to ask for the 35-105 f3.5 zoom?
3. What is a reasonable price to ask for the 50mm f1.8 lens?
4. What is a good camera to consider?

Thanks for your help.



Chuck Weinstock				weinstock@sei.cmu.edu
Software Engineering Institute		(412) 268-7719
Carnegie Mellon University		(412) 268-5758 (Fax)
Pittsburgh, PA 15213
From: bjs@uts.amdahl.com (Barry Sherman)
Newsgroups: rec.photo
Subject: Re: selenium wash
Date: 28 Aug 92 19:32:50 GMT
Followup-To: rec.photo
Organization: Amdahl Corporation, Sunnyvale CA

Serge Oligny writes:

>are after one of the two following effects:
>
>    a) get archival characteristics for their prints,
>    b) get a color change in their prints.
>
>A) In the case of archival characteristics, I use Kodak Selenium Toner
>   diluted 1:20.  I pour the solution in a tray and simply agitate each
>   print for 6 minutes.  I then wash them for 15-20 minutes in running
>   water (I use RC papers).  This procedure gives the prints a very slight
>   purple cast and deepens the blacks a bit.  

It might be worth noting that toning characteristics vary from paper
to paper.  I've found that with Oriental Seagull VC Select, toning
goes very quickly.  I usually yank them after 30-60 seconds in fresh 
Kodak Selenium Toner diluted 1:15.  This time can expand considerably
as the toner gets exhausted.  And I have to be careful as they'll
quite quickly take on a noticibly pinkish hue if left in too long.

Ilford Multigrade Fiber Base, on the other hand, seems to require 
more in the range of 5 minutes or so before the (to me) objectionable
warm-greenish hue of the untoned paper changes to the pleasing purple-
black color of the toned paper.

Barry

-- 


|----------------------------------------------------------------------------|
| Barry Sherman, Amdahl Corp.       | "Any fool can face a crisis - it's     | 
| bjs@ruts.ccc.amdahl.com           |  this day-to-day living that wears you |
|                                   |  out." - Anton Chekhov                 |
|----------------------------------------------------------------------------|
| Amdahl, being a corporation, is a legal fiction.  Therefore it is incapable|
| of holding, let alone expressing, opinions.  Unfortunately, this has been  |
| said of me as well.                                                        |
|----------------------------------------------------------------------------|
Newsgroups: rec.photo
From: gsm@mendelson.com (Geoffrey S. Mendelson)
Subject: Re: Needed info on Sigma 90mm macro as a standard
Organization: Mendelson Computer Consulting
Date: Thu, 3 Sep 92 10:16:11 GMT

sawicki@src.dec.com (Filip Sawicki) writes:

>I am looking for a good lightweight standard lens for my Minolta 9000.
>Standard means 85-100mm of course (50mm is good for ... well, what?). 
>Minolta products (100mm and 100mm macro) are _huge_, to big co carry
>around.
>
>   If you have any experience with Sigma 90mm macro lens (in any
>mount, with any camera), please let me know. Last issue of PP does not
>say to much, and I could't find reviews in other magazines. I am a
>poor student, so I have to know what I get for my money.
>
>   How this lens performs at longer distances is my main concern. As
>far as I know, real macro lenses used to be corrected for close-ups,
>what somehow degraded their quality at infinity. What about Sigma? I
>will use this lens for portraits (where color rendition at wide-open
>aperture is very important) and for mountain landscapes on slides
>(where the resolution does matter).

I don't have any experience with that Sigma lens, but I have used many
different macro lenses (e.g. Nikon, Cannon, Tamron).

Some of the early macro lenses were enlarging lenses in camera mounts and
performed poorly at long distances. This is where they got their reputation
for being bad at infinity. Zoom lenses with a macro setting are mostly 
disapointing (except for flowers where the poor edge focus is desirable).

The recent (say last 20 years) macro lenses are perfectly fine at infinty,
the lenses I have personally used include the 55mm f3.5, f2.8 and f2.8af
micro nikor. The 50mm(? I'm not sure it's been a while) EOS macro,
and the Tamron 90mm macro. 

The one Sigma lens I have owned is an 18mm f2.8. It is a little fuzzy at
the edges at f2.8 and perfectly fine at f5.6 or smaller. The Nikon 18
I have is sharp corner to corner at f2.8, but it was 4 times the price.

I suggest that you find a camera store that will let you try the lens. Most
good stores will let you put the lens on your camera, point it out the door,
(or even take it outside) and let you shoot a few frames.

Geoff.
-- 
Copyright (C) 1992, Geoffrey S. Mendelson.              All Rights Reserved.
Except for usenet followups, may not be reproduced without permsission.
----------------------------------------------------------------------------
|                   |  Computer Software Consulting    |                   |
----------------------------------------------------------------------------
Geoffrey S. Mendelson        Ask me about UNIX(tm) based imaging systems.
geoffrey@mendelson.com            
(215) 242-8712
From: CCGM@MUSICM.MCGILL.CA (Glen Matthews)
Newsgroups: rec.photo
Subject: RE: T-Max films
Date: 31 Aug 92 01:41:48 GMT
Organization: McGill University Systems Inc (MUSIC/SP)

.. and my 2 cents worth, as well ...
Newsgroups: rec.photo
From: badboy@netcom.com (Jay Keller)
Subject: San Jose, CA Photo Fair 8/29-8/30
Date: Fri, 28 Aug 92 23:57:39 GMT
Organization: Netcom - Online Communication Services (408 241-9760 guest)
Distribution: CA

There will be a Photographic Swap meet tomorrow (Saturday 8/29) and the day
after at the Santa Clara County Fairgrounds in San Jose.
 
I believe it starts at 10 AM (it could be 11, look in the classified section
of the newspaper).
 
This is an excellent fair, usually, it's held about 4 times a year and there's
usually lots of sellers (maybe 150 or so on average).  All kinds of photo
stuff.  
 
Admission in the past has been $5, and $3 to park across the street from the
fairgrounds.

Take highway 101 to Tully Road, then west to the Fairgrounds.
 
Regards,
 
Jay Keller
badboy@netcom.com

(Not connected with the fair, just a regular customer)


Newsgroups: rec.photo
From: ka1gt@cbnewsm.cb.att.com (robert.m.atkins)
Subject: Re: Rechargable type of lithium batteries?
Organization: AT&T
Distribution: na
Date: Fri, 28 Aug 1992 19:18:21 GMT

In article <1992Aug28.171143.28603@gallant.apple.com>, chuq@gallant.apple.com (Chuq Von Rospach) writes:
> konkkola@jyu.fi (Markku Konkkola) writes:
> 
> >About 6 rolls in my EOS 10 with EF 2.8/300 - is it a long time??
> 
> No, but I'm averaging 45 rolls per battery on my Maxxum 7xi, so perhaps it
> isn't the lithium battery in itself, but the power efficiency of the camera
> and the quality/freshness of the batteries? 
> 

Note that the 300/2.8 has the type of USM motor that draws a lot of current
EVEN WHEN USED IN MANUAL FOCUS MODE. Canon specifically say that the rolls
per battery figures they give do not apply when using the big heavy USM "L"
series lenses. The small "consumer" grade USM lenses draw the same amount
of power as the regular Canon EF series lenses.


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

Newsgroups: rec.photo