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View Full Version : Computars, Apo-Kyvytars, puffery and confusion - how quickly we forget



Dan Fromm
6-Nov-2016, 08:26
This archived listing popped up in the For Sale section today: http://web.archive.org/web/20161106151556/http://www.largeformatphotography.info/forum/showthread.php?134590-FS-three-Computars-for-ULF-240-270-305mm The seller claims that the lenses he offers have enormous coverage.

His listing referred to this old discussion http://www.largeformatphotography.info/forum/showthread.php?10255-The-Computar-lens-and-ULF-coverage/page10 (this link goes to p. 10 of the discussion, not to its start). It is safely put away on archive.org. See the Burleigh Brooks propaganda that the seller kindly put up in post #97 of the discussion.

The propaganda disagrees strongly with the coverage claims in the for sale listing. It also says that two of the three lenses the seller offers are plasmat types. The third lens on offer is an f/6.8er and there seems to be no solid information on the type. I calculated that the seller claims the lenses cover ~95 degrees. I could be mistaken, but I don't believe there are any 95 degrees plasmat types.

Also read the discussion from the beginning. Its very interesting. Starts out with extravagant coverage claims and great enthusiasm, peters out in confusion and disappointment over coverage claims not met.

Randy Moe
6-Nov-2016, 08:38
Thank you

jnanian
6-Nov-2016, 10:57
i photographed a 8x10 ground glass using my cellphone and while you can't see it well in the photograph
the 150f6.3 illuminates ( i would hate to say "covers" ) it without a problem.
i use this lens on 5x7 without any coverage problems and ive wanted to put it on a larger camera and measure
the image circle because while i have heard it has a large image circle, ( and expereinced no issues )
ive also been told it doesn't have a large image circle at all. the lens was on a 8x10 sinar board when i i bought it
and the person who sold it to me said the guy who had it before me used to use it all the time on his 8x10
( product close ups? macro work? who knows ) i've talked to people who know more then me often about this lens
because i've heard conflicting info, and was told by jim at mepex that there were supposedly some of these lenses
that had "large coverage" but he had never come across any, ..
while the attached photo is of the ground glass and is kind of dark ( sorry its from a big box i use to expose retina prints )
originally i used a huge sheet of waxed paper and even though i got a massive image on it, ( the box is 11x14+ ) there was
a huge glare spot so i went ahead and put a 8x10 glass+ its frame on box and a book inside the "camera".
i could easily move the ground glass frame around without loss of image .. but unfortunately the image is dark
so you really can't see what i saw ...
all i can say is its bigger than 5x7, how much bigger i don't want to say.

neil poulsen
6-Nov-2016, 12:09
My questions regarding the thread were, whether or not the negatives would stand up to enlargement and queried some of the participants about this. I think that the claims related to contact printing only.

BrianShaw
6-Nov-2016, 12:43
This message has been deleted by BrianShaw

Dan Fromm
6-Nov-2016, 13:50
My questions regarding the thread were, whether or not the negatives would stand up to enlargement and queried some of the participants about this. I think that the claims related to contact printing only.

Neil, what was posted was mostly fuzzy and vague. Many hands were waved.

Lachlan 717
6-Nov-2016, 14:01
My experience:

I have had three 240mm lenses in this class. A Graphic Kowa locked in its barrel, and two Computars in Copal 3s shutters.

All easily cover 7x17" with movements. My current Computar maxes out the rise on my camera (approx3").

All have been sharp in the corners.

The GK was sharper than my first Computar, so I kept the GK.

I just got the second Computar and put it in a like-new Copal 3s. It is sharper than the GK, so the GK will be going.

Oh, and they all easily cover wide open, although I would never shoot them as such.

Corran
7-Nov-2016, 08:27
Potential buyers should look first for direct experience from the seller, not "should" or "could" claims. Secondly they should investigate claims made by people who've actually photographed with said lenses (see above). Finally, they should investigate any changes made over the years on said lenses and what exactly the serial numbers are to get a sense of production timeline.

The lenses in question are expensive. I would love to know if the 240mm could come close to covering 8x20, and if it could I would buy it. I have a 240mm GK like Lachlan above which doesn't quite cover but would cover 7x17 - so if the Computar has a bit more coverage then it could stretch to 8x20...but that is a supposition. If it was cheap enough I would buy it to try it out.

My 305mm G-Claron lens, older Dagor design, covers 8x20 but off-hand one might be "dubious" of that claim. Since I've used it...I can state more firmly. I will have to re-read the ad and see what claims were made and which were actual tested.

Taija71A
7-Nov-2016, 09:20
12-Sep-2014, 11:34 #101

http://www.largeformatphotography.info/forum/showthread.php?10255-The-Computar-lens-and-ULF-coverage/page11


Thanks for posting this John. I've added a link to this page to my list of useful lens-related links...

Some people... Forget more quickly than others.

Randy Moe
7-Nov-2016, 09:30
Potential buyers should look first for direct experience from the seller, not "should" or "could" claims. Secondly they should investigate claims made by people who've actually photographed with said lenses (see above). Finally, they should investigate any changes made over the years on said lenses and what exactly the serial numbers are to get a sense of production timeline.

The lenses in question are expensive. I would love to know if the 240mm could come close to covering 8x20, and if it could I would buy it. I have a 240mm GK like Lachlan above which doesn't quite cover but would cover 7x17 - so if the Computar has a bit more coverage than it could stretch to 8x20...but that is a supposition. If it was cheap enough I would buy it to try it out.

My 305mm G-Claron lens, older Dagor design, covers 8x20 but off-hand one might be "dubious" of that claim. Since I've used it...I can state more firmly. I will have to re-read the ad and see what claims were made and which were actual tested.

Bryan, Mine is untested. Is your 305 G-Claron like this one? I think this version does not fit a Copal 1 shutter, but I have not tried it. I have no idea about coverage.

157093

Corran
7-Nov-2016, 09:40
Bryan, Mine is untested. Is your 305 G-Claron like this one? I think this version does not fit a Copal 1 shutter, but I have not tried it. I have no idea about coverage.

Looks like mine. The older ones fit a Compur #2. However, they still used the #2 shutter for a bit after switching from the Dagor design to the Plasmat. My Dagor is a very late 10,995,xxx serial, while the Plasmat type is 11,838,xxx - but both fit the same shutter. Supposedly the switch is at 11 million serial but considering how close my Dagor is to the edge I'm not sure if it's a clean break.

The Plasmat just clips the corners on 8x20. Would be perfect for 7x17 or 11x14, or 8x10 with huge coverage. It sits on my shelf because I only bought it to steal the shutter from, to go on my Dagor.

Lachlan 717
7-Nov-2016, 10:09
Got to get me a 305mm G Claron soon...

Michael Kadillak
7-Nov-2016, 13:38
This archived listing popped up in the For Sale section today: http://web.archive.org/web/20161106151556/http://www.largeformatphotography.info/forum/showthread.php?134590-FS-three-Computars-for-ULF-240-270-305mm The seller claims that the lenses he offers have enormous coverage.

His listing referred to this old discussion http://www.largeformatphotography.info/forum/showthread.php?10255-The-Computar-lens-and-ULF-coverage/page10 (this link goes to p. 10 of the discussion, not to its start). It is safely put away on archive.org. See the Burleigh Brooks propaganda that the seller kindly put up in post #97 of the discussion.

The propaganda disagrees strongly with the coverage claims in the for sale listing. It also says that two of the three lenses the seller offers are plasmat types. The third lens on offer is an f/6.8er and there seems to be no solid information on the type. I calculated that the seller claims the lenses cover ~95 degrees. I could be mistaken, but I don't believe there are any 95 degrees plasmat types.

Also read the discussion from the beginning. Its very interesting. Starts out with extravagant coverage claims and great enthusiasm, peters out in confusion and disappointment over coverage claims not met.

I have the 305mm f9 Computar lens that exhibits tremendous coverage and I have serious reservations that the f6.8 quasi version of the lens has anywhere near the circle of effective illumination. When you look at the front elements of the two lenses and where they are in relation into the lens body and you see immediately why one would cover 8x20 with too to spare and the other one cannot.

sepiareverb
7-Nov-2016, 19:02
Until actual manufacturer specs are posted I think this will need to remain an open question.

Dan Fromm
7-Nov-2016, 19:04
Until actual manufacturer specs are posted I think this will need to remain an open question.

They are posted. Follow the second, I think, link in post #1 in this discussion.

Lachlan 717
8-Nov-2016, 01:04
Until actual manufacturer specs are posted I think this will need to remain an open question.

You don't believe me?

WGAF what the specs are? They were process lenses. The specs would refer to an area of critical quality. Usually, this is not required for Ulf photography.

Many process lenses have a massive area outside this specification. G Clarons exemplify this. As do my GK and Computar.

So, the proof is in the eating, not in the specs.

Dan Fromm
8-Nov-2016, 06:30
Lachlan, sepiareverb, before we go farther into chest beating and perhaps rock throwing, let's pause for a moment to think about what coverage means. The generally accepted definition is "puts good enough image quality at the edge of the image circle."

And then let's stop to think what "good enough image quality" means. Contact printing needs less image quality than projection printing (enlargement).

Keep all this in mind, explain what you mean when you say "lens x has lotsa coverage for my purposes" and these silly quarrels just might evaporate.

Lachlan 717
8-Nov-2016, 18:18
Dan,

This is not chest beating.

It is someone using the lens who is reporting their experience with it being questioned/dismissed by someone with unsubstantiated (if any) experience with the lenses.

So, to settle this once and for all, I recorded my evidence here:

http://www.largeformatphotography.info/forum/showthread.php?134659-240mm-Graphic-Kowa-on-ULF-images-from-the-corner-(a-k-a-coverage)

Jim Galli
8-Nov-2016, 21:03
Some of the claims are true. Some of the 210, 240 270mm lenses are 6 glass 6 group and really do perform stellar. The 270 f9 with that construction covers a whopping 520mm circle. And they are some of the sharpest lenses I've ever used. The 210 covers 8X10 with nice movements. People used to claim they would cover 1114 but I couldn't get there. Not with 210.

What happens is people assume that the family is identical in characteristics. But the need for giant coverage goes away after 270 which was competing for small shop, large picture work with W. A. G-Claron etc. So by 305mm they didn't use the 6-6 construction and the 305 f9 Graphic Kowa as well as the 360 both actually cover less than the comparative G-Claron does.

150's covering 8X10 is a pipe dream. Like the 210 ~ 1114 myth. Been there, tried that. I wish they had made a 6-6 180mm though. It would have gotten the job done on 8X10.

So, don't throw the baby out with the bath water. Some of them really are niche lenses. I have 11X14 Deardorff and that 270 is an imortant part of that kit. Rather like a 28mm on 35mm format. A nice wide field. And the 210 is go-to on 5X12, 7X11 and 8X10. It would work on 10X12 if I had one.

jnanian
9-Nov-2016, 12:56
150's covering 8X10 is a pipe dream.

maybe ...
i stuck it on a 8x10 camera about 1hour ago ( couldn't photograph the ground glass )
the lens wasn't centered, was wide open, and it barely clipped 2 corners but covered the other 2 corners had room to spare.
if i get a chance i will stick it on a 11x14 get a tape measure and point it across the bay.

Jim Galli
9-Nov-2016, 13:40
maybe ...
i stuck it on a 8x10 camera about 1hour ago ( couldn't photograph the ground glass )
the lens wasn't centered, was wide open, and it barely clipped 2 corners but covered the other 2 corners had room to spare.
if i get a chance i will stick it on a 11x14 get a tape measure and point it across the bay.

Somewhere I have a similar negative of our town from a high hill with a 150mm G-Claron on 8X10. The corners go dark, but sure, most of it is there. I could maybe cut a 6X10 out of it if pressed. If that's good enough for general photography, I concede, but for most of us, it isn't.

jnanian
9-Nov-2016, 14:04
Somewhere I have a similar negative of our town from a high hill with a 150mm G-Claron on 8X10. The corners go dark, but sure, most of it is there. I could maybe cut a 6X10 out of it if pressed. If that's good enough for general photography, I concede, but for most of us, it isn't.


hi jim
if i could have figured out a way to center it or use rise/fall to get the image circle centered on the ground glass
it might have been able to cover even better, BUT i was using a lensboard ( 8x8"? 8x8" ?) made from a federal express shirt box
and a hole cut in the middle and blue painter's masking tape holding the speed graphic board in place. the lensboard itself was taped on the front standard
so i couldn't use the movements i wanted to, and it is a "portrait" camera so no back rise-fall movements for me... oh well .. im guessing the legendary commercial guy
who used this legendary lens on his 8x10 used it for portraits or product work/macro work so he really didn't care 1 iota about coverage at infinity.
and you hit the nail in the head, i'm not one who really cares too much if the lower corners are a tiny bit dark as it sits taped to a fed ex box, taped to the front of the camera.
i'll concede too, it probably barely "illuminates" a 8x10, probably works OK with 6x8, i know it works great wtih 5x7 ... and it will be going back on the speeder and toyo and szabad
after i click "post quick reply" ///have a nice nite !