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View Full Version : Weird Coverage with Wollensak 159mm Velostigmat ?



Cor
13-Feb-2011, 06:32
I mounted my (to me) new Wollensak Velostigmat Wide Angle Series III f9.5 8x10 6 1/4 inch (159 mm). Had some problems with the Betax no3 shutter (see other thread (http://www.largeformatphotography.info/forum/showthread.php?t=72111&highlight=cor)) but that is solved now.

So I mounted it and to my disappointment and surprise it does not cover 8*10, I would say perhaps only 5x7 or even just 4x5). The lens clearly states 8x10 as well as info I could find on this lens state that 8x10 should be covered with ease.. !

How can this happen? The front serial number is 274167, the back element reads 4167.

What does surprise me, not being familiar with these lenses is, when you look at an element from the front the element there is a grey rim of about 10mm making a smaller circle of the glass surface, if you screw out an element you can see from the back that this grey ring is caused by the mounting of the glass ( see photographs below..is this the way it should be? I guess so..


(I bought the lens form a friendly gentleman, who is currently in holiday, and upfront told me that I could return the lens if I did not like it..well I like it for it's compactness and the excellent state, a light WA lens for my 8*10..but if it does not cover it has no use off course)

Best,

Cor

eddie
13-Feb-2011, 06:57
what is your definition of cover?

i think it is within a couple of mm of the diagonal of an 8x10 sheet......not "with ease". the f12 version may cover slightly more.

maybe you should look at my lens here (http://www.largeformatphotography.info/forum/showthread.php?t=71340) if you are serious about covering 8x10 with a 165mm ish lens. a MUCH better choice.

i used my 159mm for serious pretzel like movements on 4x5.

Cor
13-Feb-2011, 07:26
He eddie,

Well with ease is perhaps exaggerated, but it should cover right ?

Now I only see a small circle (say 5 cm wide) sharp, and the rest of the view is very unsharp, that should not be, but why?

That Angulon sure is nice, but it is huge compared to this Wolly, and so is it's price..;-).. I am not really looking for massive coverage..

Best,

Cor

eddie
13-Feb-2011, 08:01
i think it is within a couple of mm of the diagonal of an 8x10 sheet......

Brian Ellis
13-Feb-2011, 08:11
I've owned two of these lenses, both covered 8x10 easily. I'd guess there's something wrong with your lens or something else along the line.

Jan Pedersen
13-Feb-2011, 08:13
Are you sure that you got the spacing correct? The wolly 159 will cover 8x10 period.

Louis Pacilla
13-Feb-2011, 08:16
How far are you stopping down the lens? I think you'll need f32 & down to f45-64 to get fairly sharp at corners .

No movement to speak of & No f 22 for less diffraction w/ these little wides.:( Ya just gotta stop 'em down when focused at infinity. If you focused much closer than that you can get away w/ f 16-22

Should work though.

BTW- it will "cover" at wider opening just a little soft @ f 16-22 in my experience.

Cor
13-Feb-2011, 08:17
Are you sure that you got the spacing correct? The wolly 159 will cover 8x10 period.

Well the elements are screwed in a Betax No 3 shutter, and cannot go in deeper, I guess this is the original combination, were could I find spacing info so I can check?

Best,

Cor

Jan Pedersen
13-Feb-2011, 08:29
Measured from the edge of the front rim to the edge of the back my f12.5 measure 32.85mm
My f9.5 Raptar measure 33.8mm
As Louis said, you will need to stop the lens down to get the entire 8x10 plane in sharp focus but there should not be any mechanical vignetting until at least 1.5" to 2" front rise.

eddie
13-Feb-2011, 08:59
http://greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=004VMm

http://www.apug.org/forums/forum44/5784-pick-n-mix.html

http://www.largeformatphotography.info/lenses-wide.html

http://photo.net/large-format-photography-forum/004fdX

http://www.allenrumme.com/lensdb/Wide%20Angle.html

Cor
13-Feb-2011, 09:02
Jan,

Thanks, I measured mine as accurate as I could with a vernier calliper, it is indeed 33.85mm, but 2 glass plates beneath and below to check if the lens is out of parallel, as far as I can see with that crude method: no.

I indeed stopped down to f45 and oddly did not see even the "sharp" part in the middle getting more Dof, although that is hard to judge a f42..defenatly the rest of the image did not get sharp..I do not understand..

Ps the 2 scans of the element look OK?

Thanks & best,

Cor

Cor
13-Feb-2011, 09:08
http://greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=004VMm

http://www.apug.org/forums/forum44/5784-pick-n-mix.html

http://www.largeformatphotography.info/lenses-wide.html

http://photo.net/large-format-photography-forum/004fdX

http://www.allenrumme.com/lensdb/Wide%20Angle.html

Thanks for the links, eddie..no mentioning of my problem though..the lens looks very nice but perhaps some of the groups/elements are out of place..

Brian Ellis
13-Feb-2011, 11:50
Thanks for the links, eddie..no mentioning of my problem though..the lens looks very nice but perhaps some of the groups/elements are out of place..

One thing to consider is that Wollensaks generally were inexpensive lenses and I doubt that their quality control was all that great. You may just have a lemon.

Brian C. Miller
13-Feb-2011, 12:03
Are you sure that you have that particular lens? I didn't notice any printing on yours, so I uploaded an image of mine.

John Kasaian
13-Feb-2011, 12:22
A Betax #3 is a large shutter for such a tiny lens. I'd be surprised if any 159 Wolly WAs came this way from the factory. Perhaps during the mounting somethingwasn't done quite right?

Chauncey Walden
13-Feb-2011, 12:46
The 1957 Wollensak catalog says that the lens came in a #4 barrel or a #3 Rapax or Alphax. And, the lens arrangement was (( (( )) )).

Chauncey Walden
13-Feb-2011, 13:14
Here's the construction of the various Wolly lenses.

Chauncey Walden
13-Feb-2011, 13:16
Well, try again.

c.d.ewen
13-Feb-2011, 13:17
Cor:

I have this lens mounted in a barrel, and a separate Betax 3. Measuring both, I note the barrel to be much shorter than the shutter. This really proves nothing, as my shutter was meant for another lens. I was just wondered about cell spacing, as too much distance might make it look like you're shooting through a tunnel. Hope this isn't a red herring.

On Brian Miller's shutter, and apparently yours, there's a chrome ring around the lens, with a single hole through it. This seems to be a lock ring for the front cell. The shutter has a central mount, which is threaded internally and externally. My best guess is that during assembly, the front cell is screwed into the middle the proper distance, then the chrome ring is unscrewed up behind the cell to lock it in place.

RE: that grey rim - I suspect it's easier to make a bigger lens than a small one, so Wolly made a bigger lens but only wanted you to use the sharper center, and thus mechanically vignetted it. If you were Jim Galli, you'd get rid of the rim and shoot the thing like an f/4 Verito. ;)

Charley

eddie
13-Feb-2011, 13:56
Thanks for the links, eddie..no mentioning of my problem though..the lens looks very nice but perhaps some of the groups/elements are out of place..

i was not trying to correct the problem. you asked about coverage.

your broken miss-matched shutter/lens issue is a different thing.

what is the problem again? maybe i am just not following.

Scott Davis
13-Feb-2011, 19:59
I've got mine (well, the f12.5 version) in an Alphax. No calipers to measure the spacing, but in that shutter, I've got sharp coverage on 8x10 or 5x12. If I apply any significant movements with it on 5x12, I do get perceptible loss of sharpness in the corners, but they remain illuminated within the range of rise/fall that my camera allows. It's one of my favorite lenses for large format. I'm pretty sure you've got a lens that's either mis-aligned or mis-configured internally for it to be that far out of whack.

Cor
14-Feb-2011, 03:11
First of all; thanks for your input its really nice to get all this feedback from the friendly people of LFPF! It is not that this lens is so valuable or something, and I can (and probably will) return it, but I would like to know/learn why this problem is occurring.

Probably I should re-phrase my problem. It is not so much that the lens does not cover, it does, it illuminates the whole 8*10 ground glass. But it is only sharp in a 5cm or so wide circle.

As if as Charley wrote: "I was just wondered about cell spacing, as too much distance might make it look like you're shooting through a tunnel."

So we all agree that the lens should cover 8*10 and stopping down did not help to improve or widen the sharp area..

My lens looks exactly the same as the one posted by Brian (thanks Brian, creative mounting btw..:) so the Betax No3 shutter is correct than.

Jan has measured his lens, and my lens seems to have exactly the same spacing (although there is some room for error in measurement).

Leaves me only the suggestions by Charley (thanks for the picture of the lens elements!) and Scott..some kind of misalignment. I looked at the 2 elements, they unscrew in 2 groups ) (is that the right way to call it like that), but I did not remove the glass from their housings. I seem to recall the inner surfaces (pointing towards the shutter were convex not concave as shown in the diagram..but I might be wrong, I'll check it tonight.

Best,

Cor

Vaughn
14-Feb-2011, 08:23
I have a Wollie 8x10 Series III EX.WA f12.5 6.25" Focus in a Alphax shutter (marked "Wollensak Rochester").

On 8x10, it is significantly dark and unsharp in all corners at f45. It should not be, so I assume that I got a dog -- one that perhaps bounced back and forth on eBay a bit..who knows... I guess I could unload it on someone for what I paid for it, but that would not be a nice thing to do.

The only saving grace is that I now have a 5x7 and it will make a great lens for that camera. And I have made some nice images with it on 8x10 on those very rare occasions that do not requite sharpness in the corners (some portraits of my boys in the landscape).

E. von Hoegh
14-Feb-2011, 11:25
Cor,
Your lens might be assembled incorrectly. I had the identical lens and shutter; it covered 8 x 10 with some movement possible at smaller stops. Also very sharp - my only issue was the lack of coating.



Good luck.

Brian C. Miller
14-Feb-2011, 14:06
creative mounting btw..:)

You can tell that it's a quality job because there aren't any wrinkles in the duct tape. ;)

(I need to get some more lens boards, is all. Three lenses are sharing that one.)

Cor
15-Feb-2011, 01:25
Mystery solved !

So last night I could check this lens again, and guess what: some genius had flipped around the 2 inner groups of both elements around! Thanks to the diagram Chauncey had kindly provided I knew that both inner surfaces should be concave, and they were installed convex!

So I flipped them around and now I have a sharp image over the whole 8*10 ground glass (the light was still dim at f9.5 it wasn't crystal clear, but it looked fine)!

Have to shoot some film at f22-f32 to really be certain..

The seller had never used the lens nor taken out the elements, still this exercise was a bit of a nuisance, so I hope my images will turn out fine.

Since this lens is uncoated how much of a problem is flare if you use a compendium, and have the sun in your back (shooting only B&W) ?

Best,

Cor

Louis Pacilla
15-Feb-2011, 06:51
Hi Cor

I figured it would cover. Glad you found the problem & worked it out. Great little lens that should produce fine results as long as you don't plan to do mural size printing.Contact prints will /should be fantastic.

You'll be fine as far as flare goes. Do use your shade & watch for strong direct light making it's way in.

Cor
15-Feb-2011, 07:57
Thanks Louis,

I'll only contact print, do not have a 8*10 enlarger (though access too through friendly dutch LF photographers..)

BTW I now understand why I was puzzled by the grey rim I saw (the pictures I posted do not show it very well). The flipped groups are painted grey on the back side, and when installed wrong as I got the lens the grey coating was facing towards the front of the lens.

Best,

Cor