HDTenEightyP/NetNews huggingface dataset:
From: johno@sdd.hp.com (John Ongtooguk)
Newsgroups: rec.photo
Subject: Re: Resolution of Lens ???
Date: 20 Nov 1992 20:55:49 GMT
Organization: Hewlett-Packard, San Diego Division
Distribution: na
NNTP-Posting-Host: hpsdlg10.sdd.hp.com

In article <1992Nov20.182843.11017@cbnewsm.cb.att.com>, ka1gt@cbnewsm.cb.att.com (robert.m.atkins) writes:
|> 
|> Taking the observation that I can get no more than about 80 lp/mm from
|> my diffraction limited f5 lens on Velvia as a starting point: 
|> (1) The USAF target requires about 20% modulation to be "resolved" in an
|> image according to an old copy of "Modern Photography"
|> (2) The MTF curve of Velvia (from Fuji literature) suggests that the MTF
|> at 80 cyc/mm is MAYBE 25% (from an optimistic extrapolation of their data
|> which only goes to about 60 cycles/mm).
|> (3) At 80 cycles/mm the MTF of a perfect f5 lens is about 70%
|> 
|> The modulation in the image is the product of the MTF of the film and the
|> MTF of the lens, so at 80 cycles/mm = .25 x .7 = .175 (17.5%) which is
|> right on the threashold of visibility.

   Isn't Fuji claiming 160 lp/mm for Velvia ? 80 lp/mm is what I usually
   hear being the accepted limit for high quality 35mm color images and
   it seems to be the case per your tests. 160 lp/mm also seems kind of
   high as while people agree that it is finer grained than Kodachrome 25 
   which is rated at 100 lp/mm some have stated that the Kodachrome 'edge
   definition' can still produce as much detail in an image. 

   It still seems that you should be able to get more than 100 lp/mm
   with your 500 f5 (Genesis as I recall) and Tech Pan, as even with 
   the above situation there still should be adequate margin at about
   200 lp/mm (?) if Tech Pan can resolve to 320 lp/mm. 200 lp/mm is
   5 microns per lp or about 0.0002in, a small distance. I'm guessing
   that most (all ?) of your testing has been performed with a tripod
   and that you might get some better numbers by using an inspection
   surface plate or laser mounting table. While you're in an inspection
   area you could also check for vibration of your setup. A microscope
   that takes a camera could also be pressed into service. 
    
   John Ongtooguk (johno@sdd.hp.com)
Newsgroups: rec.photo
From: kting@cse.unl.edu (Kea Ting)
Newsgroups: rec.photo
Subject: Re: Nikon N90, 28-70D lens - HELP
Date: 20 Nov 1992 06:11:48 GMT
Organization: University of Nebraska--Lincoln	
Distribution: world
NNTP-Posting-Host: cse.unl.edu
Keywords: Vignetting, N90/F90, 28-70/3.5-4.5D AF lens

krish@leland.Stanford.EDU (venkatraman) writes:

>Well, it's a great camera and quite happy with it but I do have a
>problem that I'm hoping that someone can explain.  I seem to be experiencing
>a whole lot of vignetting at 70mm when I use larger apertures.  It
>seems to start at about f16 and is very pronounced by f5.6 and f4-f3.5.
>I shot a bunch of test slides and it's just too obvious to ignore.

>BTW, I have a Nikon UV filter on the lens, I've tried both with and without
>the Nikon hood recommended for the lens and it does not seem to be be
>that pronounced at shorter zooms but then I haven't really tested for
>it.

>(Note the phenomenon I'm describing is a noticeable darkening of the
>corners and I'm assuming that that's vignetting, do (!) correct me if
>I'm wrong)

    Try to take off the UV filter and do some test ,
the UV filter ring might be too thick. Try to test it withoud the filter
and with the filter both at the 28mm and 70mm. If it is vignetting, the slide
corner darkening at 28mm should be a lot more when compare with slide that
take at 70mm.  
     Good luck.

--
soon

University Of                  Disclaimer :
Nebraska-Lincoln               I always speak for myself.
From: jwhitnell@cup.portal.com (Jerry D Whitnell)
Newsgroups: rec.photo
Subject: Re: Seeking Advice on Camera Vendors
Date: Thu, 19 Nov 92 20:58:28 PST
Organization: The Portal System (TM)

Vijay Kashyap writes...
|I am planning to buy from Beach Camera. I have already ruled out
|Cambridge Camera Exchange, New York based on info from this news
|group. Please advise. Thanks.

One suggestion is that you spend the extra money on 2-day delivery (UPS
blue).  This will give you a guranteed date on which the package shows
up on your door step.  With ground, it shows up any old time, so you have
to wait three weeks to report it missing.

Jerry Whitnell (speaking with the voice of experience).
Newsgroups: rec.photo
From: jacobson@cello.hpl.hp.com (David Jacobson)
Subject: Re: Depth of field equations
Date: Tue, 17 Nov 1992 17:14:33 GMT
Organization: Hewlett-Packard Laboratories

In article <1992Nov14.200535.17240@cs.rit.edu> kar@cs.rit.edu (Kenneth A Reek) writes:
>
>	In "The Camera", Ansel Adams gives the following formulas which, he
>says, will "be sufficiently accurate for use when the subject distances are
>large, but not for close-ups."  I'll venture an opinion on the disclaimer
>later.
>
>F = lens focal length
>f = f/ number
>c = diameter of circle of confusion (in same units as F)
>u = subject distance (in same units as F)!!
>
>                        FF    <- that's F squared
>Hyperfocal distance H = --
>                        fc
>
>                                Hu
>Near limit of depth of field = -----
>                                H+u
>
>                               Hu
>Far limit of depth of field = -----
>                               H-u
>
>	The formulas for both near and far depth of field differ from the
>previous poster's; I think that his formula for the far limit is just wrong.
>I will venture a guess that his formula for the near limit (same as this one
>except that F is subtracted from u in the denominator) is correct, but assumes
>that you are measuring distance from one of the nodal points of the lens
>instead of the film plane.
>
>	My speculation on Adams' disclaimer is related to this.  The
>difference between measuring from the film-plane and from the nodal point is
>insignificant for large subject distances, but not for small ones.  My
>guess is that Adams simplified the real formulas to produce these simple
>approximations; they are close enough for most work and less threatening to
>math-o-phobes.

Adams' formula is exact, even for macro work, under the following
conditions: 

1.  The circle of confusion is small compared with the aperture.
(Almost always true.)

2.  You are not doing macro work OR the diaphragm looks the same size from
front and rear.  (Usually true.  The diaphragm on ultra-wide angle
lenses often appears to be different from front and rear, but you
would seldom use such a lens for macro work.)

3.  You interpret f as the *effective* f-stop, in other words, it is
already corrected for bellows factor.

4.  The subject distance is measured from the front *focal* point.
That is one focal length in front of the front nodal point.  (You can
find it by turning the lens around and observing where the image of a
distant object is sharp.)  Most physics texts display formulas
assuming distances are measured from the nodal points.  The focusing
scales on most cameras are calibrated from the film plane.

  -- David Jacobson
From: philg@zurich.ai.mit.edu (Philip Greenspun)
Newsgroups: rec.photo
Subject: Re: Picture matting/framing
Date: 23 Nov 92 18:02:12
Organization: M.I.T. Artificial Intelligence Lab.
Reply-To: philg@martigny.ai.mit.edu
NNTP-Posting-Host: zug.ai.mit.edu
In-reply-to: bmahler@javelin.sim.es.com's message of 19 Nov 92 05:49:58 GMT


Real fine art photographs are seldom mounted at all.  You'll see them
taped to the back of the window mat along the top edge.  The rest is
left free for wrinkling and thermal expansion.

Annie Liebowitz's museum show was done this way.  I do my pictures
this way and although it would be nice if they were flatter, I just
look at them straight-on.


--

      -- Philip Greenspun

-------------------------------------------------------------
MIT Department of Electrical Engineering and Computer Science
545 Technology Square, Rm 433, Cambridge, MA 02139
(617) 253-8574
Newsgroups: rec.photo
From: tse@ra.nrl.navy.mil (Anthony Tse)
Subject: Re: Camera Feature Wars - Photo Getting Like Video
Organization: Naval Research Lab, Washington, DC
Date: Tue, 17 Nov 1992 19:29:27 GMT

In article <1992Nov17.181239.22048@noao.edu= lytle@noao.edu (Dyer Lytle  CCS) writes:
=In article <13850@texsun.Central.Sun.COM> dbernard@clesun.Central.Sun.COM writes:
=>The other beneficiary, beyond the fast snapper (and I mean no slam) and the
=>battery-maker and the neophyte, is the camera vendor.
=
=Indeed, but the experienced camera user can also benefit from the introduction
=of new models since the older models, once superceeded by the new models,
=often find their way to the used market and can be picked up for quite a bit
=less than their new price.  Because of this, one can probably pick up a
=Nikon N8008, (by all accounts a fine, modern, AF camera), for quite a bit less
=than the new price 2 or 3 years ago.  Just don't buy the newest model, always
=wait a couple of models, you probably won't lose much in the process but
=you will save quite a bit of money.

	I wish this is true for outdated MF camera.  The price for a F1
has gone way out the roof.  I got mine for $600 a few years back new,
now an used one cost about the same.  And Canon don't even make FD
lens anymore.

-Anthony
Newsgroups: rec.photo
From: robertw@bmerh654.bnr.ca (Robert Williams)
Subject: EOS Rebel IIs vs competitors
Organization: Bell-Northern Research Ltd., Ottawa
Date: 20 Nov 92 09:40:17

I'm interested in buying an autofocus SLR, and am looking for some
advice.  I'm looking for a camera that is very simple to use, with
good AF, built-in flash.  My budget is in the $500-600 (Cdn) range, so
my list of cameras looks like this (all with 35-70 or 35-80 zoom lens
from the manufacturer):
    Canon EOS Rebel IIs
    Pentax PZ10
    Minolta Maxxum 3xi
    Nikon F-401 (a bit expensive, though)

To be honest, I didn't like the power zoom on the Maxxum 3xi -- it was
too hard to stop it where I wanted.  I prefer a manual zoom.  Are
there any big differences between the AFs on these four?  I'm worried
in particular about tracking rapid movement (like my 4-year old
running around the yard).  How about metering?  Any other opinions?
Any cameras I've missed?

Thanks.    . . . Rob Williams
--
Robert R. Williams    Bell-Northern Research Ltd.,   Innovative ideas often
Ph:  (613) 763-2513   P.O. Box 3511, Station C,      meet with violent opposit-
Fax: (613) 763-2202   Ottawa, Ontario, Canada.       tion from mediocre minds
Email: robertw@bnr.ca K1Y 4H7                            ... Albert Einstein
Newsgroups: rec.photo
From: parry@yoyo.cc.monash.edu.au (Tom J Parry)
Subject: Help: Color compensation of photos
Originator: parry@yoyo.cc.monash.edu.au
Organization: Monash University, Melb., Australia.
Date: Tue, 24 Nov 1992 01:48:06 GMT

Can anyone tell me the nature of the compensation which is done
to color photos when they are printed?  Is there any literature
which describes this?

Thanks in advance for any help.

-- 
Tom J Parry.
Your reality is a figment of my imagination.
From: jspirer@rain.next.com (Jeff Spirer)
Newsgroups: rec.photo
Subject: Re: Nikon 6006 advice
Date: 15 Nov 92 23:35:21 GMT
Article-I.D.: rosie.5877

In article <1992Nov15.021032.3582@dartvax.dartmouth.edu>  
Jimmy.Tung@dartmouth.edu (Jimmy Tung) writes:
> Sounds like the photofinisher screwed up.... So the end result
> is that a careful photofinisher should be able to get good prints if
> they put the time and effort into it.  Don't know if you're paying for
> it though...
> 
Which is why I always get contact sheets instead of prints when I shoot  
print film.  I am surprised that this is so rarely suggested when there  
are so many complaints about sloppy photofinishers. 

I have a custom lab make a contact sheet.  I use that as a reference when  
I go to a reasonably low cost local photo shop to get the right prints.   
This has never once resulted in a problem with the final result. 

Jeff
Newsgroups: rec.photo
From: "martin tai" <martin.tai@canrem.com>
Subject: toronto 110 developer
Reply-To: "martin tai" <martin.tai@canrem.com>
Organization: Canada Remote Systems
Distribution: rec
Date: 21 Nov 92 08:38:28 EST

Any one can recommend  good  110  developer for  4x5 size
prints ?  I  got  the first set of print from one
developer  for  Rollei E110.  The  prints  are very poor
quality, out of color and  focus.  Using  20x  magnifier
I can see the  image on  the  negative is tack sharp,
as expected  of  a Zeiss Tessar.  There would be no problem
to enlarge to 8 x10,  not to mention 4 x5. But this developer
even screw up 4x5.
   Any good  developer in Toronto area, who can handle
run of the mill  110  print size of 4x5  consistantly,
preferably using  automated machine like the one used in
35mm ?
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044
From: feltman@hpscit.sc.hp.com (Robert Feltman)
Date: Mon, 16 Nov 1992 22:18:46 GMT
Subject: Re: Need help selecting a truly compact camera
Organization: Hewlett-Packard, Santa Clara, CA
Newsgroups: rec.photo

Re:, Olympus Stylus. I just purchased the Stylus as a back-up camera
and took it out on its "maiden voyage" last week-end, shooting T-max 100.

I was quite pleased with sharpness (compaaring to my view camera results),
and contrast. I am not sorry i bought it. I was not able to try the lens
before I bought. As you know it is truly "compact", which may be its
biggest weakness. I found it difficult to hold steady enough in low light,
where the shutter speed is reduced. In open shadowed forest (fairly dark),
it would have produced excellent results on a pogo stick that drinks de-caf:-
metering was great, I was too shakey.

For those who may want to know, it will focus to 14", there is a flash-off
mode as well as reg., no-redeye, and backfill mode. It will EASILY fit in a
shirt pocket.

Bob
Newsgroups: rec.photo
From: denny@view (Denny Page)
Subject: Labs in the SF Bay Area
Organization: Views.
Distribution: ba
Date: Thu, 19 Nov 1992 17:56:56 GMT

In a article on Chrome printing Barry mentions a bay area lab, "Calypso",
which reminded me that I have been wanting to try a different lab than the
one I have been using.

I have been using JP labs in Mountain View, and have found their service to
be generally ok, but not extreemly satisfying for me.  It may just be my
type of photography - JP seems oriented toward wedding photographers, which
I am not one of.  JP also does not do Cibachrome, which I have occasionally
wanted.

Does anyone have any BA labs that they would recommend?  I am interested in
a professional lab capable of handling 4x5 negatives.  Reasonable pricing
is of interest :-).

Denny
Newsgroups: rec.photo,misc.forsale
From: bremner@cs.sfu.ca (David Bremner)
Subject: 4 sale: Canon Autowinder A & Screw Mt. Bellows REPOST
Summary: make me an offer
Reply-To: bremner@cs.sfu.ca (David Bremner)
Organization: CSS, Simon Fraser University, Burnaby, B.C., Canada
Distribution: na
Date: Sat, 21 Nov 1992 18:08:30 GMT

The Graflex Optar is sold. 

I still have:

1) A Canon Autowinder for A series. In very good condition. With soft case
and instructions manual.  I am under the impression that this is 
worth around $50 U.S.

2) A screw mount bellows that says ASAHI bellows unit.  Has a nice geared
monorail marked with f=58mm and 0.6 to 2.2x.  This is in even better 
condition.  I think this is worth around $25 U.S.

As the tentative pricing may have indicated, I'm open to offers, and or
trades of K/mount stuff/cable releases/tripods/clamps/other must have stuff.

David
-- 
bremner@cs.sfu.ca 				          ubc-cs!fornax!bremner
Xref: sparky rec.photo:20172 rec.scuba:6133
From: falk@peregrine.Eng.Sun.COM (Ed Falk)
Newsgroups: rec.photo,rec.scuba
Subject: Address for Southern Nikonas?
Date: 19 Nov 1992 23:46:55 GMT
Organization: Sun Microsystems Inc., Mountain View, CA
NNTP-Posting-Host: peregrine

Hi all; anybody have an address/phone # for Southern Nikonas?  All I
know is that they're in Texas.

--
		-ed falk, sun microsystems
		 sun!falk, falk@sun.com
To be loyal to rags, to shout for rags, to worship rags, to die for rags 
-- that is a loyalty of unreason, it is pure animal (Mark Twain).
Newsgroups: rec.photo
From: acs@csri.toronto.edu (Alvin Chia-Hua Shih)
Subject: Re: Changing N8008 for the new Canon?
Date: 18 Nov 92 19:24:39 GMT

In <1992Nov18.154643.10186@sequent.com> blue@sequent.com (Gil Delavous) writes:

>To conclude, I think Nikon has made a really big marketing error with the N90
>D lenses. They should have realized that if people have to change all their
>equipment, it's easier for them to look for another constructor. 

I don't follow.  Isn't the N90 compatible with the SB-24?

Also, by not having "D" lenses, all you lose is "3D matrix metering".
I was under the impression that with non-D lenses, you'd just get
"classic" matrix metering--which was pretty good.

ACS
-- 
 ___ ___ ___ ______________________________________________________________
|   |   | __|      Democracy is not a way of getting better solutions.     |
| - | --|__ |           It's just a way to spread the blame.               |
|_|_|___|___|______________________________________________________________|
Alvin_C._Shih____________________acs@csri.utoronto.ca______________________|
From: robert@sys.sweden.dg.com (Robert Claeson)
Newsgroups: rec.photo
Subject: Re: different camera names in US - why ?
Date: 16 Nov 92 08:30:43 GMT
Organization: Data General AB, Akalla, Sweden

In article <1992Nov6.120549.28716@spider.co.uk>, mikec@spider.co.uk (Mike Coren) writes:

> I think it has more to do with deterring high-volume grey market importers
> than individuals who purchase the cameras outside the US (or outside Europe
> or outside Asia, depending on your frame of reference).  I recently bought
> an EOS-100 in the UK, which is the EOS-ELAN in the US, and with it came a
> list of Canon's world-wide service network, along with a statement to the
> effect that any Canon camera could be serviced anywhere in the world.
> 
> When you look in the ads in Popular Photography, and they show the same item
> costing $30 more with a US warrantee, you know you're getting grey market
> merchandise.

Yes, but if the camera comes with a world-wide warranty, why would one
need a U.S. warranty?

-- 
------------------------------ END OF MESSAGE ------------------------------
Robert Claeson                Internet: robert@sys.sweden.dg.com
Data General AB                         robert@sys.dg.se
Box 28                             CEO: robert@sys.sweden.dg.com:dg-smtp
S-164 93 KISTA                     Tel: +46 (0)8-92 55 00
Sweden                             Fax: +46 (0)8-751 36 22
From: moreaux@litsun22.epfl.ch (Michel Moreaux)
Newsgroups: rec.photo
Subject: Need advice : what about Cambridge for e-mail order ?
Date: 23 Nov 92 13:36:01 GMT
Distribution: rec
Organization: Laboratoire d'informatique technique


I plan to buy a large format camera. I decided to deal with Cambridge for
the buying of the lenses. When reading this newsgroup, I have found a lot of
people having trouble with Cambridge. Is it really a pain in the ... to treat
with them ? Is there any valuable alternative ?

_Michel Moreaux
--
------------------------------------------------------------------------------
Michel Moreaux,                           | "Ceux qui ne savent rien en savent
Ecole Polytechnique Federale de Lausanne  |  toujours tout autant que ceux qui
Departement d'Informatique                |  n'en savent pas plus qu'eux"
Laboratoire d'Informatique Technique      |                  P. Dac.
EL-Ecublens                               |___________________________________
CH-1015 Lausanne                           
Phone # : (21) 693-46-72,   e-mail : moreaux@litsun.epfl.ch
------------------------------------------------------------------------------
From: tonyp@mcs213j.cs.umr.edu (Tony Phillips)
Newsgroups: rec.photo
Subject: Re: Turning photos into jig-saw puzzles
Date: 16 Nov 92 16:57:38 GMT
Article-I.D.: umr.1992Nov16.165738.1463
Organization: University of Missouri - Rolla

In article <1992Nov16.041719.23724@dartvax.dartmouth.edu> Jimmy.Tung@dartmouth.edu (Jimmy Tung) writes:
>It's on the wrong side of the country, but Vermont Color provides this
>service.  I think that the photomug, photopuzzle, photocalendar, photo
>T-shirt, photo statue-doodads, etc. business must be booming because it
>seems that many 60 minute places out here offer these services.
>
>e-mail for the number.  They have a mail-order service also, but I use
>one of the local shops.

York Photo Labs also offer these services.

I didn't see the original post, but since the prior message says that Vermont
is on the wrong side of the country, I'll post York's West Coast address(es):

P.O. Box 7685
San Francisco, CA  94120

P.O  Box 38850
Denver, CO   80238

P.O. Box 3715
Seattle, WA  98124

I don't have any affiliation with York, just passing along the info.


-- 
|  Tony Phillips-  University of Missouri CS Dept.  |  Programming: A noun   |
|                                                   |  meaning 'The Art of   |
|  Reply to:  tonyp@cs.umr.edu                      |  debugging a blank     |
|  Prefered Address:  S102066@UMRVMA.UMR.EDU        |  sheet of paper'       |
Newsgroups: rec.photo
From: sli@athena.mit.edu (Sheung L Li)
Subject: Using a Polaroid back
Organization: Massachusetts Institute of Technology
Date: Wed, 18 Nov 1992 15:55:57 GMT

What are the differences between the various types of Polaroid film?

Does anyone have any experiences with NPC backs?  Specifically, I'm 
interested in the difference between the NPC back and the various 
incarnations of the Mamiya RZ Polaroid back.


Newsgroups: rec.photo
From: prodger@leland.Stanford.EDU (phillip prodger)
Subject: How to remove cloth tape
Organization: DSG, Stanford University, CA 94305, USA
Date: Wed, 18 Nov 92 20:32:19 GMT

I recently sent an M.A. Bravo print that I had matted to be framed.

I used corner mounts when I mounted the print to avoid any residue
on the back of the image - especially as Bravo signs the backs of
his prints.  I gave very explicit instructions to my framer that he
should not use any additional adhesives and that I would live with
any shifting/bowing of the image that resulted.

Well, sure enough, I just opened the frame and found that the shop
added two cloth adhesive hinge mounts to the print.  

Question:  How can I completely safely, completely invisibly, 
remove the cloth tape from the print?  Is this a conservation job?

The image is on standard, commercially manufactured silver print paper.
From: yavor@acpub.duke.edu (Yavor B. Parashkevov)
Newsgroups: rec.photo
Subject: Re: FM & FE + MD11 or MD12
Date: 20 Nov 92 22:54:37 GMT
Organization: Duke University; Durham, N.C.

In article <7127@news.duke.edu> yavor@acpub.duke.edu (Yavor B.
Parashkevov)
writes:
>The manual for FM2 describes MD12 as the only drive to use. It also says
>that when attached and turned on, the MD12 will supply power to the
>meter in order to conserve the camera's battery.

Crap, crap, crap! I take all that back. Sorry, I must have been
sleeping while writing this or maybe even worse. I apologize for the
misinformation. Guess I have been thinking about the F3 and the MD-4.
Still, I'd like to know how usable is the MD-11 with an FM2. Ah, could
anyone tell me how noisy/quiet it is and how much vibrations it
produces (the MD-11 or MD-12 that is). I own a generic brand which is
so noisy, animal photography is out of the question   :-(  It's OK for
shooting candids during a party or a rock concert, though  ;^)

Regards,


Yavor Parashkevov

e-mail: yavor@acpub.duke.edu
snail:  2422 W Club Blvd
        Durham, NC 27705-0325
        USA