HDTenEightyP/NetNews huggingface dataset:
From: peltz@cerl.uiuc.edu (Steve Peltz)
Subject: Degrees Kelvin
Organization: Computer Based Education Research Lab - University of Illinois
Date: Mon, 23 Nov 1992 23:21:59 GMT

Okay, stupid question time, and maybe this should be in sci.physics, but
I couldn't find a FAQ list.

What is the basis for defining different light temperatures by degrees
Kelvin?

Can you recommend a decent book for understanding light/optics/photochemistry
that doesn't require a major theoretical background?
-- 
Steve Peltz
Internet: peltz@cerl.uiuc.edu	PLATO/NovaNET: peltz/s/cerl
From: eugene@briar.lle.rochester.edu (Eugene Kowaluk)
Newsgroups: rec.photo
Subject: Pen ink on a negative
Date: 20 Nov 92 19:36:32 GMT
Distribution: na
Organization: UofR Laboratory for Laser Energetics


Tom Epperly writes:
> I have a small dot of blue ball point pen ink on one of my negatives.
> A pen dropped on the negative while I was filling out a form to get an
> enlargement of it.  Is there a safe way to remove ink from the
> negative?  The ink is on the side opposite of the emulsion.


I mark all my scientific films after processing.  This amounts to upwards
of dozens of images per day.  When errors occur I use ethyl alcohol USP 200
proof with a low-lint cloth like Kaydry.

However, all my inks are indelible (i.e., waterproof), and alcohol is an
easy cleanup.  Your's might be water soluble.

I would have a concern more from the indent your pen made than a way to
clean up the ink.


eugene kowaluk
Newsgroups: rec.photo
From: rspeirs@javelin.sim.es.com (Ron Speirs)
Subject: Re: Contrast mask for Ciba's 
Organization: Evans & Sutherland Corp.
Date: Fri, 20 Nov 1992 19:36:09 GMT

In article <b4eP02CY2bJo01@JUTS.ccc.amdahl.com> bjs@RUTS.ccc.amdahl.com (Barry Sherman) writes:
>Anthony Tse writes:
>
>>> Much about masking ciba deleted.
>>
>>	What kind of masking film do you use?  I tried TMAX100 and that
>>plain doesn't work.  The film shrank after drying and the registration
>>became way off, not to mention the boulder size grain.  
>
> [Barry Sherman's decription of using Bob Pace's book and Pan Masking Film]

Another article about masking with Pan Masking film appeared in Darkroom
Techniques Magazine:  "Cibachrome Masking for Contrast Control", 
March/April 1984, Page 18.

Has anyone had any experience with the "Minit-Mask" glass device used for
contrast control?

Ron Speirs, Evans & Sutherland Computer Corp., Salt Lake City, Utah

Newsgroups: rec.photo
From: kavka_mb@indtech.it.ilstu.edu (Mike Kavka)
Subject: Re: photography in ice rinks
Date: Fri, 20 Nov 92 01:16:16 EST
Reply-To: kavka_mb@indtech.it.ilstu.edu (Mike Kavka)
Organization: Illinois State University

I shoot ice skating pics all the time.. my suggestion is to use ektar 1000asa film from kodak w/ a FLD filter.. the FLD corrects the mercury vapor lights to a daylight balance wich print film is.. that will correct your problem.
Mike


********************************************************************************Michael Kavka                               kavka_mb@indtech.it.ilstu.edu
The Phantom
********************************************************************************

   "Who's more foolish?
        The fool or the fool who follows him?"
From: Gen.M.Kanai@dartmouth.edu (Gen M. Kanai)
Newsgroups: rec.photo
Subject: Re: Opinions on Nikkor 50/1.2 AIS vs 50/1.4 AIS
Date: 15 Nov 92 15:16:33 GMT
Article-I.D.: dartvax.1992Nov15.151633.19028
Organization: Dartmouth College, Hanover, NH
X-Posted-From: InterNews1.0a5@newshost.dartmouth.edu

In article <MULLINS.92Nov14140628@media-lab.media.mit.edu>
mullins@media.mit.edu (Atty Mullins) writes:

> 
> Anyone out there have any opinions on these in terms of optical
> quality, i.e., sharpness ? I'm considering buying one and can't
> justify the extra $$ for the 1.2 unless it is also sharper.
> 
> Also, does anyone have any opinions regarding AIS lenses and their AF
> "equivalents", e.g., the 35/2 AIS vs. 35/2 AF ? In my experience the
> AIS lenses seem to be of much sturdier construction than the AF
> lenses. Is there also a difference in sharpness, max F-Stop, etc.
> 
> Thanks, Atty

Atty,

All my lenses are Nikkor AIS lenses and I use an F3 (which seems to
becoming obsolete as I type), so my bias is such.  I do not yet like
Nikon's newer equiptment because I knew that up until the N90, Nikon's
AF system just did not match Canon's or Minolta's.  

I have the 50/1.2 and I love it.  I have read that it is marginally
sharper, but I like it because I find it easier to focus with and I
wanted the fastest lens.  You might not be able to justify the extra
cost, and that's cool, but if you are planning on buying either the 35,
85, or 105, I suggest that you seriously look at spending more for the
fastest lenses.  The difference in sharpness is more significant in
these lenses.  IMHO.

I really haven't taken a serious look at the AF lenses so max f-stop I
don't know about, but in terms of sturdiness, there can be no question.
 My two photographer friends both eschewed the AF lenses because of the
plastic construction and the feel of the focus rings.  One of my
friends has an ancient 50/1.4 that he had modified AI and it is an
incredible lens.  Almost 25 years old and I really doubt that a plastic
lens will last that long.

My vote is such: if you are serious, I really do not think AF in these
mm is an option.  I feel that AF has its uses (zooms etc.) but if you
cannot focus almost as quickly on an MF as the F4 can on AF, then you
have some work to do.  The AIS lenses will last for the long haul, this
has been proven.  I suppose it's the age old "you get what you pay
for," or, "buy now, pay later."  

Another HUGE factor in my purchases of AIS lenses was the fact that
Nikon is discontinuing the whole line of AIS lenses.  !!!  Think about
that.  In 2-3 years, all you will be able to buy will be AF or used
AIS.  I hate the process and work that goes into buying a used lens, so
I buy mine new.  So, there is that to consider as well.  In fact,  you
will very soon have a hard time finding the slower versions of the
lenses.  The fast lenses of each mm will be the last to go.

Hope this helped,  e-mail for any other questions...
gen
From: elau@berlioz.nsc.com (Eugene Lau)
Newsgroups: rec.photo
Subject: Re: putting photos on a wall.. (?)
Date: 15 Nov 92 21:42:54 GMT
Organization: National Semiconductor Corporation, Santa Clara

In article <Bxq0Jp.G5G@cs.dal.ca> graham@ug.cs.dal.ca (Michael Graham) writes:
>I want to put a whole bunch of my B&W 8x10's and 5x7's on my *plaster*
>wall. Is there a way to do this without ruining the photos or the wall?
>2 way tape? Is there anything else? Does the tape come off the photos?
>
>mike

unless you can get archival 2-way tape, the tape will eventually yellow, and
you will find your print on the floor.  I assume your main concern is the 
fact that your wall is plaster, which means you don't want to hang a frame.
you can mount your prints using gatorfoam, which is brittle foam sandwiched
between two pieces of cardboard.  mount print on gatorfoam, mount gatorfoam
on wall.  the result is a professional looking display that is cheap, child
and earthquake safe, and will have your in-laws saying "WOW".

eugene
Newsgroups: rec.photo
From: mhoesing@cwis.unomaha.edu (Michael Hoesing)
Subject: Re: Idiot Mistakes
Organization: University of Nebraska at Omaha
Distribution: rec
Date: Tue, 17 Nov 1992 04:23:40 GMT

jimc@tau-ceti.isc-br.com (Jim Cathey) writes:

>In article <1e8j6iINN7gu@crcnis1.unl.edu> kting@cse.unl.edu (Kea Ting) writes:
>>a few small spot on the edge of the frame. The reason is the film have a
>>layer that prevent the light to go thought it when it is not processed,
>>after the processing the layer will be removed by the chemical.

>I think only some films have this opaque backing layer.  Kodachrome and
>movie films come to mind.

 It's probably not related at all, but I opened the back of my camera
for about five seconds (Of shock, before I slammed the back shut :-)  )
in bright sunlight.  I got the negatives back, expecting the worst,
but not a single frame was bad.  The only way that I knew which frame
I opened it on was a thin line on the edge of the negative.  This
was with a 8008s and Vericolor 400.  I was VERY happy that they came
out, and I have never made the same mistake again.


Newsgroups: rec.photo
From: accwai@math.uwaterloo.ca (Andy Wai)
Subject: Re: Jobo CPE2 CPP2
Organization: Math Faculty Computing Facility, University of Waterloo
Date: Mon, 23 Nov 1992 17:37:21 GMT

In article <ALC.92Nov23095254@gdstech.GRUMMAN.COM> alc@gdstech.GRUMMAN.COM (Al Chang) writes:
>
>CPE2 - Lowest cost but doesn't go as large as the CPP/A 2. I have the
>CPP(?)2. It is the middle one of the three. The CPP/A goes to 20X24
>size print while the CPE2 only to either 16x20 (or 11x14). Thats the
>only difference betweem the two lower models.

The CPE has fixed rotation speed.  I think the older version has two
speeds while the new version can do 70rpm only.  That's way too fast
for film processing.  And as I recall, the CPE doesn't have  a pump
to circulate water between the upper and lower trough.  That slows
down temperature correction and creates local hot spots in the bath.

>The higher of the three 
>support allows a water hookup for rapid water cooling and a more  
>accurate digital temperature control. The accuracy is more important
>when you develope film which I don't plan on doing.

Actually, the convenience of digital temperature setting is far more
important than anything else.  Dial in the processing temperature,
throw in water a couple degrees below, go away for half an hour and
you're all set.  The cold water intake is also quite handy if you do
b&w film in the summer.

Andy Wai
From: v101gwud@ubvmsb.cc.buffalo.edu (Urth tones)
Newsgroups: rec.photo
Subject: need advice on buying a Crown Graphic
Date: 15 Nov 92 23:25:00 GMT
Distribution: na
Organization: University at Buffalo
News-Software: VAX/VMS VNEWS 1.41


	I've an offer of a "Crown Graphic 45" for $250 and I think it's a steal
but know nothing about it really.  If you're reading this before 25 November 
1992 then please send your advice.
	Will Kennedy -- State University of New York at Buffalo
	[my own opinions]
Newsgroups: rec.photo
From: CARDOSO <CARD@UNB.CA>
Subject: *FOR SALE*: KODAK's PRISM SYSTEM
Organization: The University of New Brunswick
Date: Wed, 18 Nov 1992 13:13:23 GMT

KODAK's PRISM XL SYSTEM
Kodak's best instant photography previewing studio system.
Complete with camera, player, monitor and 80 data disks.
Optional second player and monitor also available.
This system is about 1 1/2 years old, and its original
price was CAN$25,000.
Reasonable offers will be considered.
Please contact me at my email address.
John Cardoso
(email: cardoso@unb.ca)

Newsgroups: rec.photo
From: tse@ra.nrl.navy.mil (Anthony Tse)
Subject: Re: Contrast mask for Ciba's (was Re: Chrome prints other than Ciba's)
Organization: Naval Research Lab, Washington, DC
Date: Tue, 17 Nov 1992 21:02:49 GMT

> Much about masking ciba deleted.

	What kind of masking film do you use?  I tried TMAX100 and that
plain doesn't work.  The film shrank after drying and the registration
became way off, not to mention the boulder size grain.  Then I tried
TechPan, that doesn't shrink and has good grain size, but I ran out
of time before I actually have a chance to make a print with it.  Then
there is the heat developed masking film, but I didn't want to buy a
100' roll before trying it first.  What is the Kodak masking film?
What are the advantage and disadvantage of these different masking
film?

-Anthony
From: elf@ohstpy.mps.ohio-state.edu
Newsgroups: rec.photo
Subject: zoom lenses
Date: 15 Nov 92 20:36:50 EST

Hello everyone, 
this is my first post so I hope everything turns out o.k..


Need some info regarding "Samyang" lenses, more specifically the 100mm to 500mm

Thanks in advance,
Eric
From: Jimmy.Tung@dartmouth.edu (Jimmy Tung)
Newsgroups: rec.photo
Subject: Re: Advice on Canon 50 mm/f1.8 wanted
Date: 18 Nov 92 22:31:21 GMT
 <BxKAxH.Byw@news.cso.uiuc.edu> 
 <1992Nov13.012756.12780@dartvax.dartmouth.edu>  
 <92322.015711KCHAN@ESOC.BITNET>
Organization: Dartmouth College, Hanover, NH
X-Posted-From: InterNews1.0a5@newshost.dartmouth.edu

Khee Chan asks:

>In article <1992Nov13.012756.12780@dartvax.dartmouth.edu>,
>Jimmy.Tung@dartmouth.edu (Jimmy Tung) says:
>>
>>I agree it's a good, solid lens.  But it's suspiciouslly
>>nonmetallic-like (maybe anodized aluminium?) compared to the old FD
> !!!!!!!!!!!!!!!        !!!!!!!!!!!!!!!!!!
>
>Wow!! Is aluminium a plastic?

Well, I realize that plastic and aluminum are not the same (some
esoteric arguments arise here about aluminum-oxide polymers existing
and plastic being a mostly carbon-based polymer, but that's avoiding
the real issue ...;-) ).  But other than the fact that I am not going
to try to dent or scratch my lens to see if the frags are plastic or
metal, the material of the case is antiferromagnetic.  The generic lens
specs says something about the lens being composed of metal and
polycarbonate, but do not specify exactly which parts of made of what.

Hope that makes things alittle more clear.
From: sog@craycos.com (Steve Gombosi)
Newsgroups: rec.photo
Subject: Re: Looking for reference material on Hasselblad
Date: 23 Nov 92 18:44:25 GMT
Organization: Cray Computer Corporation

In article <vessey.6.722537512@UPEI.CA> vessey@UPEI.CA (Blair Vessey) writes:
>
>I recently got a good deal on a used Hasselblad 500C with a 80mm 2.8 planar 
>and other assorted goodies for my wife's birthday.  I'm looking for a good 
>book(s) on Hassies, specifically dealing with available accessories and 
>perhaps the history behind the brand.  Shutterbug has some info on what 
>pieces folks have for sale, but I'd like to come close to a "comprehensive" 
>listing of all the bits and pieces.
>
>I have seen references to a book by Wildi (sp?).  Can anyone tell me what it 
>covers?

Everything ;-). Ernst Wildi is a consultant to Hasselblad - his book covers
just about every camera, lens, back, and accessory made by Hasselblad
since the old 1600F. There's a brand new edition out (adds coverage of the
TCC line).

It's published by Focal.

Steve
From: pd@sics.se (Per Danielsson)
Newsgroups: rec.photo
Subject: Re: Major advances in camera technology (was Re: Camera Feature Wars - Photo Getting Like Video)
Date: 22 Nov 92 15:40:31 GMT
	<1992Nov20.180516.28628@noao.edu> <98631@netnews.upenn.edu>
Organization: Swedish Institute of Computer Science

In article <98631@netnews.upenn.edu> liang@saul.cis.upenn.edu (Chuck Liang) writes:

>1960's.  TTL exposure metering.  I'm not sure when exactly this was
>invented and which was the first camera in incorporate it (Pentax
>Spotmatic?).  This feature really made SLR's a favorite.

It was a Topcon camera. I don't recall the model name.

>Around 1975(?).  The Olympus OM2n introduced TTL-OTF flash metering.

Nope, not the OM2n. The original OM2 had OTF flash metering.
--
Per Danielsson				pd@sics.se
Swedish Institute of Computer Science, PO Box 1263, S-164 28 KISTA, SWEDEN
Newsgroups: rec.photo
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Disclaimer on Photos
Date: Mon, 23 Nov 1992 17:36:09 GMT
Distribution: usa
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Nov20.170012.21673@samba.oit.unc.edu> rslugg@med.unc.edu (Robert Slugg) writes:

>In addition to marking roll# and frame # on the backs of proofs, most labs
>are starting to add some sort of copywrite message with your name and
                                  ^^^^^^^^^

You mean copyright message.

There is a difference.
From: tommy@pool.Eng.Sun.COM ()
Newsgroups: rec.photo
Subject: Any used OM4/OM4T for sale ?
Date: 17 Nov 1992 20:56:57 GMT
Organization: Sun Microsystems, Inc.  Mt. View, Ca.
Distribution: usa
Reply-To: tommy@pool.Eng.Sun.COM ()
NNTP-Posting-Host: pool


I am interesting in buying a used OM4 or OM4T.  Does anybody out there 
like to get rid of his/hers ?  Please reply me via the e-mail.


-tommy
From: sog@craycos.com (Steve Gombosi)
Newsgroups: rec.photo
Subject: Re: Resolution of Lens ???
Date: 19 Nov 92 21:47:25 GMT
Distribution: na
Organization: Cray Computer Corporation

In article <1992Nov19.180913.3777@cbnewsm.cb.att.com> ka1gt@cbnewsm.cb.att.com (robert.m.atkins) writes:
>In article <1992Nov19.025409.2162@walter.bellcore.com>, jchen@wind.bellcore.com (Jason Chen) writes:
>> In article <1992Nov18.192154.236@cbnewsm.cb.att.com> ka1gt@cbnewsm.cb.att.com (robert.m.atkins) writes:
>> >since the resolution made by the latter technique is also influenced by the
>> >film resolution (and maybe by camera shake!). This is clearly seen by the fact
>> >that it is almost impossible to get more than 100 lp/mm when testing any lens
>> >using normal film (including K25, Velvia, or Tech Pan), wheras almost any
>> >lens shows higher resolution than this in the film plane. I have a 500mm f5
>> >that clearly resolves over 250 lp/mm in the film plane and yet I have never
>> >measured better than 80 lp/mm on film (Velvia), despite using the bigest
>> >tripod I can carry (Bogen 3051) and mirror lock-up.
>> >
>> Indeed, I found the film resolution to be the most limiting factor in most
>> cases. However, I don't think 100 lp/mm is hard to achieve. With a good 
>> microscope (not those found in Toys'r Us), TMAX-100, and well saturated 
>> exposures, you should be able to resolve close to 125 lp/mm.
>> 
>
>Jason,
>     Do you speak from experience or theory? I know from published film
>specs that I SHOULD be able to resolve 125lp/mm, but I can't. I use a 
>Zeiss microscope (not available form Toys'R Us!) to examine negatives and
>slides. The resolution just isn't there. There was an article which I have
>somewhere at home, in which Modern Photography tried to resolve >100 lp/mm
>using every trick they could. Flash exposure, the best (Nikon, Canon, Zeiss,
>Leica) 50mm lenses, the sharpest (Tech Pan, K25 and a bunch of other) films
>they shot at all apertures to get the best possible results etc... They found
>that the BEST lens at its BEST aperture on the BEST film could only just
>squeak by with 100 lp/mm (maybe 101 or 102 lp/mm). They could easily get
>numbers in the high 80's to low 90's but 100 lp/mm was very, very hard.
>Even then these numbers were only in the center of the field.
>If you have test slides or negatives showing 100 lp/mm resolution (vertical
>and horizontal patterns resolved) I'd really like to see them and try to
>figure out what I'm doing wrong!

Maybe I don't understand how this all works, but aren't the resolutions
of the lens, film, and system (lens *and* film) related in this way:

	1/Rs = 1/Rl + 1/Rf

If that's true, and Rs = 100lp/mm and Rf = 320 lp/mm (for Tech Pan),
that means that your lens has to resolve better than 145 lp/mm.

That ain't too shabby.

What does Kodak claim for TMX resolution?

Isn't it around 160 lp/mm?
If so, then your lens has to resolve 267 lp/mm to get 100 lp/mm
reolution on the final negative. I don't think you're doing 
anything wrong - I think you're a victim of algebra.

I've probably misremembered the formula...donl or David J. will
probably straighten this all out for us.

Steve
From: philg@zurich.ai.mit.edu (Philip Greenspun)
Newsgroups: rec.photo
Subject: Re: Konica Infrared 750 B&W Film
Date: 20 Nov 92 07:14:39 GMT
Reply-To: philg@martigny.ai.mit.edu
Organization: M.I.T. Artificial Intelligence Lab.
NNTP-Posting-Host: zug.ai.mit.edu
In-reply-to: castellano_joe@Tandem.com's message of Wed, 18 Nov 1992 21:16:59 GMT


Here's some advice:

Konica IR film is good stuff, but bracket if you aren't in standard
lighting conditions and use a big camera.  I find the grain to be only
marginally acceptable when enlarging to 8x10 from a 6x6cm camera.  I
wouldn't plan on going over 8x10 if you are shooting 35mm.


--

      -- Philip Greenspun

-------------------------------------------------------------
MIT Department of Electrical Engineering and Computer Science
545 Technology Square, Rm 433, Cambridge, MA 02139
(617) 253-8574
From: ark@alice.att.com (Andrew Koenig)
Newsgroups: rec.photo
Subject: Re: Nikon N8008S vs. N90 - opinions wanted
Date: 16 Nov 92 18:22:29 GMT
Article-I.D.: alice.24208
Reply-To: ark@alice.UUCP ()
Organization: AT&T Bell Laboratories, Murray Hill NJ

In article <1992Nov16.092722.10638@ulrik.uio.no>  writes:

> The 28-70 is the better of the two lenses going down to 28mm.

How do you know?  (I'm not challenging your statement, but would like
to know your source(s)).
-- 
				--Andrew Koenig
				  ark@europa.att.com
Newsgroups: rec.photo
From: sbertsch@magnus.acs.ohio-state.edu (Steve Bertsch)
Subject: Re: candid photo lens? is there such a thing?
Organization: University Systems
Date: Sat, 21 Nov 1992 02:10:09 GMT


Porters Camera Store has a right angle mirror gizmo for $39.95.
Call (800) 553-2001 for the free catalog.

I have no vested interest in Porters, just thought I'd pass this along.
-- 
bertsch.3@osu.edu
Newsgroups: rec.photo
Subject: canon EOS 1000FN (or Rebel IIS)
From: jenny@gphs.vuw.ac.nz (Jenny Rollo)
Date: Mon, 23 Nov 1992 20:27:04 GMT
Organization: Institute of Geophysics, Victoria University of Wellington, NZ

Hi,

Recently I posted a request for people's suggestions on good 35mm SLR cameras, as
I am considering buying one.  I have been very grateful for the response, and hopefully have replied to everyone who sent me e-mail...

Since sending my request I have been reading every book on photography I can lay my hands on, and looking around all the camera shops.  The two cameras I am tossing up between are the Canon EOS1000FN (equivalent to the Canon Rebel IIS) or the Canon EOS100 (equivalent to the Elan).  The price of both these cameras (which both come with a 35-80mm lens) is $995 and $1600 respectively (NZ dollars).  It seems that cameras are a lot more expensive in NZ than they are in the U.S in particular.  This brings me to 



my point.  I am goint to Surfers Paradise and Brisbane at the end of next week and want a camera for this trip.  I would be very grateful if anybody living in Australia (especially this area) could give me a price on both these cameras (Australian dollars), and I can see if it is worth waiting until I get over there or buying it before I leave.  Unfortunately they don't sell Canons at duty free shops in Wellington.

Thanks in advance.

Jenny Rollo.
From: mlindholm@cc.helsinki.fi
Newsgroups: rec.photo
Subject: Re: Camera Feature Wars - Photo Getting Like Video
Date: 20 Nov 92 14:23:05 GMT
Organization: University of Helsinki

(This message is not to anyone personally, just thoughts which have risen
lately, so don't flame.  Otherwise, comments are welcomed.)

Our whole technological culture is based on the idea that everything must be
made to work ever more perfect.  If a machine can be built, that is enough a
justification to build it.  No concern is given to whether it is needed at all
or even whether it is downright bad for people (or nature).  Engineering is our
new religion: we have to make progress.  No one knows why, but we just have to. 
And we want all those marvellous new technological advancements.  No one knows
why, but we just want.

And the more technological and the more artificial the world we live in is, the
more stressing our life becomes, because we are not living in a world for which
we were meant to.  Our abilities are not needed.  Machines do everything
better.  And there comes the inevitable frustration.  Not perhaps individually,
but on a collective level.

If we think of a hobby photographer, which I think most of the readers of this
list are, I see no reason why every shot should be perfect.  Isn't he joy in
photography in gambling?  That you can never be quite sure what the outcome is. 
To appreciate the successful photos, one must also experience failures.


Mikko Lindholm
mlindholm@cc.helsinki.fi
Newsgroups: rec.photo