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UltravioletPhotography

Opinions on the UKA optics quartz lenses


dabateman

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I know at least two members here have or had these uncorrected lenses. I could not find comments on them, but some images. Based on cost, these are almost affordable and was wondering what people thought when they used them or moved up from them.

I am thinking about maybe getting the 78mm one. The 25mm f2.8 is "cheap" but would only work on my Em1. The 50mm f3.5, 60mm f 3.5, 78mm f3.8 and 105mm f4 are t-mout and would work on my Sigma SD14, Olympus E510 full spec and even my SLR/n.

I know they are best for single wavelengths, but I would mainly only use them for uv anyways.

I think my ideal lens would be the Pentax 85mm m42 quartz lens. But that seems to be extremely rare.

I look forward to any experiences.

Thank you.

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Hi Da Bateman. I have the 78 mm version, and it is certainly more UV transparent than any non-quartz lens I've used. While it is very good for UV imaging, by design it changes magnification of the subject/image when adjusting focus - which does not work well with focus-stacking. Also on account of its uncorrected design, it does suffer focal shifts which are very strong in normal VIS imaging (so much so that I refuse to use it for VIS). This also means that (for me at least), it is not a good lens to use for shooting multispectral image sets (which include UV up to IR). I also wish I got a shorter focal length.
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Thank you Mark,

Your most critical comment about not being good for focus stacking, really makes me pause. I think focus stacking would be one of my primary uses for the lens.

Thank you.

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Also these kind of lenses are not chromatically corrected so you could see fringing or other aberrations.
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Hi Da,

I started out way back in 2013 with the 105 mm UKA. There was a significant amount of chromatic fringing on my visible light images and if you looked closely enough on the UV shots through a Baader U filter and of course there was a significant focus shift going from visible to UV. So I pawned the family jewels and went for the 105 mm Rayfact and have never regretted that.

Dave

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I have the 25mm and 50mm and can offer that both, while uncorrected, can produce usable UV images. I was always impressed with Dave's work with his. I recall some time back, somewhat jokingly, commenting that I did not think that through a Baader U there was much "chroma" to "abberate" :D but clearly an uncorrected lens is never going to compare to a fully corrected lens.

 

One thing they excel at is narrow band imaging, 365nm LED reflected UV for example.

 

I can also add the 50mm and 78mm are built like tanks and the T-mount leaves lots of space for rear mounting filters on mirrorless cameras. The c-mount 25mm UV3528B has an image circle larger than spec at infinity and is usable on micro four thirds. The new 35mm C-mount looks better for µ4/3.

 

Correction: Looking again at the diagram of the UKA UV3528B it appears to fat to fit into the recess of a c-mount to µ4/3 adapter.

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Thank you all for the comments.

I had not seen the 35mm before, but you're correct its too fat. The cmount to M43rds adapter I got needs 37.2 for infinity. I don't even think it would mount on mine as I remember the maximum diameter must be less than 50. This is 57.5, so very fat.

 

Based on Jonathan, sensor sensitivity tests, It looks like less than 360nm, is not so good anyways. Compared to what I know, which has been published for the Sigma sensor, this seems nearly universal.

 

So instead of getting a cheaper quartz, I got some other lenses to play with. The Wollensak 25mm f1.5, the sigma 30mm f2.8 art and the El-Nikkor 80mm f5.6. All much much cheaper together than the cost of the 25mm f2.8 quartz I was considering.

Also I got a cmount to M42 mount adapter to see how macro the Wollensak becomes on my Sigma SD14 and Olympus E510. If not too bad I may reconsider the 25mm quartz. But I think I would need to wait and get a Monochrome full spectrum camera to really reap the benefits of a quartz lens.

Thanks, David

 

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Andy Perrin
The Wollensak I own, but it can’t really be described as sharp, at least on my APS-C sensor. If you want a lens that makes pics that look kind of old timey then it’s nice. The lens itself was only produced up to the 1940s I think? At least if we are talking about the same one.
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Yes I did see your foot picture. Mine is not bad. You may need to screw the front section all the way in, to see if it improves sharpness. I thought my Yus 135mm f2.8 lens was horribly soft. But then one day noticed the front section of the lens was not tight. It similarly to the Wollensak, un screws into 2 sections. Once tight, I now find it to be quite acceptable. For the Wollensak, see if the copper "hood" section is loose. If so then tighting it may improve sharpness. Otherwise, just maybe I am lucky, as mine was in mint condition in box with original daylight filter. I don't think it was used much. I did pay $120 for it, so was not cheap.
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Andy Perrin
Nah, the very center part of my lens is okay sharpness, but it softens fast toward the edges. It is just not that great a lens. As you say, it might be my particular copy, but keep in mind I am using it on APS-C, so my sensor is even larger than the image circle, with lots of vignetting. Could be okay on a different smaller sensor.
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I haven't critically looked at images in the corners yet, maybe I shouldn't. I typically print 8x10 or square. So that is not usually an issue.

The APS-C sensor is only 2mm larger vertical than 43rds, so not huge if you print 8x10 or square. The extra width is usually cropped out. But if you like 4x6 or 8x12 prints, then I could see a possible issue.

What I did first off notice is that its not very UV permissive. I was hoping to use it for UV video at f1.5. But did not get great settings at midday uv levels. At 4pm Eastern, was at 1sec, iso 1600, f2 with Baader venus filter. Not great at all, my 35mm f3.5 can do almost the same at f4.

But I will need to test with my convoy flash lights, once the batteries arrive. The flash lights came fast, but batteries I have been waiting extra 2 weeks.

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But I will need to test with my convoy flash lights, once the batteries arrive. The flash lights came fast, but batteries I have been waiting extra 2 weeks.

 

I can recommend this battery supplier (not affiliated)

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