Rolleicord Vb - pristine condition, but the Xenar is very soft in the corners.

[albireo]

I really shouldn't buy more TLRs. I have a 3.5F III which is currently being CLAd. I also have a Rolleicord Va - which is one of my favourite cameras. It is sharp corner to corner at f/8 or above.

However it so happens that a Rolleicord Vb popped up on the local ads. The asking price was right. The condition seemed incredible. I thought I would go for it, given the condition and given some of the supposed (minor) ergonomic advantages over the Va. I decided I could always sell my Va at a later stage. And so I went for it.

Upon opening the box I was speechless. The Vb was not simply in excellent condition. It was stone cold mint. I have never seen a TLR with the leatherette in such perfect condition. No wear at all. Everything clicks and pops into place nicely. Both lenses are pristine. The viewfinder pops open with the satisfying fresh springy action that whoever has owned a 3.5F or 2.8F will know very well. It's one of those 'time machine' cameras we sometimes stumble upon.

So I went ahead and shot and developed a couple of rolls of Delta and Foma to test it. I went with a range of apertures, as usual, fully prepared that this is a Xenar, and that a certain amount of 'character' in the rendering around the edges was to be expected.

To my surprise, sadly, the edges are very blurry even at f/8. The blurriness is *noticeably* worse than with my Va. Things are better f/11 and above though something is still off. I should say focus appears to be spot on, and centre performance is fine AFAICS. I seem to get reasonably sharp negatives in the centre even at f/3.5.

So what might determine the poor corner performance? A few thoughts:
1. sample variation - is it possible that the Xenar, being a non-professional (so I'm told) lens, was on occasions poorly matched or poorly aligned to the body? Is it possible I was just spectacularly lucky with my Va in that it has a perfectly matched Xenar?
2. Tampering - is there any sort of tampering that might have happened and would have affected lens performance? Could it be that an unscrupulous former owner might have taken apart the lens and replaced some of the components with lower quality elements? If so, is there a way to detect if the Xenar is intact?
3. Nothing to do with the lens itself. Could it be that the lens is fine, but something else is off? I cannot see any body misalignment anywhere. The lens plate appears to be perfectly parallel to the body. The film cover has no dings, bumps etc I can detect. The pressure plate perhaps? Could a worn out pressure plate exert differential pressure across the film surface within the frame, in such a way the the corners are warped but the centre is in focus?

Any thoughts appreciated.

 

[Dan Daniel]

Remove the back and put the shutter on B, open shutter, and sign a light through from the back. Haze? Spots? Oil from the shutter can gas off over the years and get deposited on the lens surfaces.

Your questions- 1) Unless the lens is defective and made it through Rollei quality control undetected, no, it should not be obviously unsharp. Sample variation exists but within a far smaller range than you describe. 2) Possible. Look at the metal mounts front and back for signs of removal. Shine a light on the front group to see if there are any signs of air spacing in the mount, as if it was opened up and the elements not remounted properly (back group is one cemented pair). You can take a finger and lightly see if the rear group is loose in the mount and can be screwed down tighter (or use a screwdriver or spanner wrench if you are certain that you won't slip and scratch the lens). 3) Alignment would lead to tilted focus plane, not spherical focus plane.

 

[gone]

Might be that someone was in there, and something is not right. I've never encountered this problem. The only thing to do is put it on a tripod w/ the lens wide open and see if you can see what the issue is. Dan has the right idea, it's such a crazy problem, I'd sell the camera. Drastic step, you say? No, it might be expensive and time consuming to figure this out yourself or send it to a shop. This reminds me of buying FSU cameras, never buy a pretty one, buy a beat up one. The shiny, pretty ones don't work, that's why they're so nice.

 

[flavio81]

I really shouldn't buy more TLRs. I have a 3.5F III which is currently being CLAd. I also have a Rolleicord Va - which is one of my favourite cameras. It is sharp corner to corner at f/8 or above.

However it so happens that a Rolleicord Vb popped up on the local ads. The asking price was right. The condition seemed incredible. I thought I would go for it, given the condition and given some of the supposed (minor) ergonomic advantages over the Va. I decided I could always sell my Va at a later stage. And so I went for it.

Upon opening the box I was speechless. The Vb was not simply in excellent condition. It was stone cold mint. I have never seen a TLR with the leatherette in such perfect condition. No wear at all. Everything clicks and pops into place nicely. Both lenses are pristine. The viewfinder pops open with the satisfying fresh springy action that whoever has owned a 3.5F or 2.8F will know very well. It's one of those 'time machine' cameras we sometimes stumble upon.

So I went ahead and shot and developed a couple of rolls of Delta and Foma to test it. I went with a range of apertures, as usual, fully prepared that this is a Xenar, and that a certain amount of 'character' in the rendering around the edges was to be expected.

To my surprise, sadly, the edges are very blurry even at f/8. The blurriness is *noticeably* worse than with my Va. Things are better f/11 and above though something is still off. I should say focus appears to be spot on, and centre performance is fine AFAICS. I seem to get reasonably sharp negatives in the centre even at f/3.5.

So what might determine the poor corner performance? A few thoughts:
1. sample variation - is it possible that the Xenar, being a non-professional (so I'm told) lens, was on occasions poorly matched or poorly aligned to the body? Is it possible I was just spectacularly lucky with my Va in that it has a perfectly matched Xenar?
2. Tampering - is there any sort of tampering that might have happened and would have affected lens performance? Could it be that an unscrupulous former owner might have taken apart the lens and replaced some of the components with lower quality elements? If so, is there a way to detect if the Xenar is intact?
3. Nothing to do with the lens itself. Could it be that the lens is fine, but something else is off? I cannot see any body misalignment anywhere. The lens plate appears to be perfectly parallel to the body. The film cover has no dings, bumps etc I can detect. The pressure plate perhaps? Could a worn out pressure plate exert differential pressure across the film surface within the frame, in such a way the the corners are warped but the centre is in focus?

Any thoughts appreciated.

I would like to know how are you assesing corner performance. Are you looking at film scans? That's a no no.

You should, ideally, be looking at the negative itself with a strong loupe or with a microscope.

So let's assume you're doing that. You meantion that the lens is "pristine". There's a high chance this camera was serviced (the lenses, thus cleaned) and something of the following happened, in most likely to least likely:

1. The alignment of taking lens to shooting lens is off, so the focus point isn't correctly sync wth the taking lens.

2. The alignment fo taking lens to shooting lens has been done for max center sharpness wide open, while these kind of lenses (Xenar) exhibit a focus shift and if you want good corners at f8, in theory some compensation should be made for better whole-frame sharpness at middle apertures in detriment to max center sharpness. There's a web page where you can see the effects of such misplacement. , check out https://web.hevanet.com/cperez/MF_testing.html and take a look at the Rolleiflexes, some of them were misadjusted giving max center performance and poor corners, and others the other way around.

3. The position of the focusing screen is off, maybe it wasn't put correctly or with the original shims in place, if there were any.

4. The lens elements, on reassembly, aren't fully tightened or some shim that should be there was lost or misplaced.

I would advise you to pick a moderate aperture as f8 and shoot many shots of the same scene, for example something at 5m or 10m distance, and vary the focus point slightly. It's likely that one of the frames will have the best overall performance.

 

[Cinema]

is the lens board aligned? observe the metal frame from the side of the camera body, with the lens just slightly protruding. make sure the body is straight and aligned with the metal frame that holds the lens

 

[Sirius Glass]

I suspect an alignment issue. Given the camera is in such good condition, the problem, once found, should be easily remedied.

 

[albireo]

is the lens board aligned? observe the metal frame from the side of the camera body, with the lens just slightly protruding. make sure the body is straight and aligned with the metal frame that holds the lens

Thanks. It is, as far as I can see. Also would a misaligned lens board result in excellent central, but poor peripheral, sharpness?

 

[albireo]

I would like to know how are you assesing corner performance. Are you looking at film scans? That's a no no.

You should, ideally, be looking at the negative itself with a strong loupe or with a microscope.

Thanks. I'm doing both. Checked via scans and via an 8x loupe on the backlit negative. Scans are not a no-no: it is easy for me to assess the problem via scans by the way. Film planarity issues due to film holder slackness (which I believe is what you're hinting at) would result in out of focus grain. What I see instead is perfectly focused grain but poor resolution.

I can also exclude scanning as the source of the issue because, as stated, I own other TLRs. Using the same scanner, the same process, the same film brands and the same film holders, other TLRs (notably, my old Rolleicord Va) are capable of much better sharpness as a function of aperture.

2. The alignment fo taking lens to shooting lens has been done for max center sharpness wide open, while these kind of lenses (Xenar) exhibit a focus shift and if you want good corners at f8, in theory some compensation should be made for better whole-frame sharpness at middle apertures in detriment to max center sharpness. There's a web page where you can see the effects of such misplacement. , check out https://web.hevanet.com/cperez/MF_testing.html and take a look at the Rolleiflexes, some of them were misadjusted giving max center performance and poor corners, and others the other way around.

3. The position of the focusing screen is off, maybe it wasn't put correctly or with the original shims in place, if there were any.

4. The lens elements, on reassembly, aren't fully tightened or some shim that should be there was lost or misplaced.

I would advise you to pick a moderate aperture as f8 and shoot many shots of the same scene, for example something at 5m or 10m distance, and vary the focus point slightly. It's likely that one of the frames will have the best overall performance.

This is excellent advice, thanks - especially your point 2. I didn't know about the focus shift issue. I will do some more testing and report back.

 

[albireo]

Remove the back and put the shutter on B, open shutter, and sign a light through from the back. Haze? Spots? Oil from the shutter can gas off over the years and get deposited on the lens surfaces.

Your questions- 1) Unless the lens is defective and made it through Rollei quality control undetected, no, it should not be obviously unsharp. Sample variation exists but within a far smaller range than you describe. 2) Possible. Look at the metal mounts front and back for signs of removal. Shine a light on the front group to see if there are any signs of air spacing in the mount, as if it was opened up and the elements not remounted properly (back group is one cemented pair). You can take a finger and lightly see if the rear group is loose in the mount and can be screwed down tighter (or use a screwdriver or spanner wrench if you are certain that you won't slip and scratch the lens). 3) Alignment would lead to tilted focus plane, not spherical focus plane.

Will do many thanks Dan. I currently have a roll of Delta 400 in camera so the above will have to wait a little.

 

[BrianShaw]

Will you please tell us how you are assessing the image quality? Also, it would help to understand the degree of blurriness... if you could post sample of a blurry negative.

Many years ago I bought a pristine Vb. The shutter release was a bit sticky so I took to a local Rollei factory trained technician. He was a bit amazed because the film tensioner showed almost no wear, meaning that the camera had hardly been used. In addition to a need for cleaning the film wind/release mechanism he noted that the focusing was a bit wonky. It seems that although rarely used it had taken a blow to the front of the camera. I didn't see that until he pointed it out and demonstrated the focus. I tend to doubt that would cause an even "fuzziness" on the peripherie but it could, I suppose, cause a fuzzines that is not even across the lens' entire image circle, which is greater than that seen in the image frame.

 

[albireo]

Will you please tell us how you are assessing the image quality? Also, it would help to understand the degree of blurriness... if you could post sample of a blurry negative.

Many years ago I bought a pristine Vb. The shutter release was a bit sticky so I took to a local Rollei factory trained technician. He was a bit amazed because the film tensioner showed almost no wear, meaning that the camera had hardly been used. In addition to a need for cleaning the film wind/release mechanism he noted that the focusing was a bit wonky. It seems that although rarely used it had taken a blow to the front of the camera. I didn't see that until he pointed it out and demonstrated the focus. I tend to doubt that would cause an even "fuzziness" on the peripherie but it could, I suppose, cause a fuzzines that is not even across the lens' entire image circle, which is greater than that seen in the image frame.

Thank you for the insight Brian - I suppose the only way to properly test the issue I'm reporting and share a usable result would be to load both my Va and the Vb with a roll (same film), place both cameras on tripod, pick a scene (perhaps a full frame printed test target and/or a a scene with high frequency minute detail?) then expose develop and scan both rolls identically. I will readily confess I have not done this test - I will see if I can put myself to it this weekend. Many thanks.

 

[BrianShaw]

Thank you for the insight Brian - I suppose the only way to properly test the issue I'm reporting and share a usable result would be to load both my Va and the Vb with a roll (same film), place both cameras on tripod, pick a scene (perhaps a full frame printed test target and/or a a scene with high frequency minute detail?) then expose develop and scan both rolls identically. I will readily confess I have not done this test - I will see if I can put myself to it this weekend. Many thanks.

It isn't quite that complicated. Comparison is nice but not necessary at all. Just post an example of your negative that you observed peripheral fuzziness.

Are you examining the negatives with a loupe?

 

[Dan Daniel]

Can you post a scan showing the issue? Maybe 1200x1200 pixels so that there is some detail. There might be something in the way the focus is shifting that rings a bell with someone.