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Explore the world of vintage lenses through repair notes, real test shots, and detailed archive threads packed with images.

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What is this spot?
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Posted: Mon Feb 07, 2022 5:25 am
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Posted: Mon Feb 07, 2022 5:25 am
Post subject: What is this spot?
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I recently acquired this lens that looks pretty dusty. With my eyes I can see a spot but couldn't figure out what it is. I read that fungus could be round and doesn't always have to branch out. So I took some pictures with a macro lens.

What is this spot?



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Posted: Mon Feb 07, 2022 5:20 pm
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Posted: Mon Feb 07, 2022 5:20 pm
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Hard to see (and hard to say for sure), but this looks like the edge blackening of the lens may have become detached there.

If so, I very much doubt you will ever notice this in any images.

Google "Schneideritis", but don't be alarmed; with only a couple of spots here and there the problem is more cosmetic than that it really affects lens performance. If the problem is more wide-spread, you may see a loss of contrast & more flare.


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Posted: Mon Feb 07, 2022 11:11 pm
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Posted: Mon Feb 07, 2022 11:11 pm
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Thank you for the response. From the pictures I have taken it does look to be Schneideritis. There is only a single spot of it. It has no impact on image quality that I can tell. This lens is blistering sharp and very contrasty. It may have just beaten my previous sharpest lens.

I was hoping it wasn't fungus so I wouldn't have to take it apart as I figure I can only make this particular lens perform worse if I do.


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Posted: Tue Feb 08, 2022 12:38 am
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Posted: Tue Feb 08, 2022 12:38 am
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cbass wrote:
. . . This lens is blistering sharp and very contrasty. It may have just beaten my previous sharpest lens. . .


Tell us more, please? Smile


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Posted: Tue Feb 08, 2022 1:34 am
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Posted: Tue Feb 08, 2022 1:34 am
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55 wrote:
cbass wrote:
. . . This lens is blistering sharp and very contrasty. It may have just beaten my previous sharpest lens. . .


Tell us more, please? Smile


It's nothing exotic. Also this one is pretty dusty.
Topcor 58/3.5 macro. The one which is just the optics and you need a variable extension tube or bellows to use.
Xenotar optical design which is known for high resolution.
Very similar if not exactly the same as Micro Nikkor 55/3.5

It has limits. It's good for close and mid distances. It does ok at infinity but will not be a top performer at infinity.

This is my second copy and I think it's slightly sharper than my first copy, but I would have to do a controlled test.

Sample picture from 16MP APS-C Fuji with lens mounted on Lens Turbo II speed booster. ISO 2000.



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Posted: Tue Feb 08, 2022 5:11 am
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Posted: Tue Feb 08, 2022 5:11 am
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cbass wrote:


It's nothing exotic. Also this one is pretty dusty.
Topcor 58/3.5 macro. . .


Thank you!
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