Lenses to evaluate for UV-Lens Technical Data

[ulf]

I am slowly populating the UV-Lens Technical Data section.

 

The slow speed is due to that each lens demands a lot of work to reach a minimum level I consider OK.

I want to have the general information, transmission data, with graphs and pictures of the tested lens in place before I temporarily leave the post and proceed to next lens or lens group.

Eventually I hope to come back and add more important different characteristics for each lens.

 

There are many lenses I can or have begun testing and I want to ask if any of them are more interesting for any of the forum's members.

If so please leave a comment to this post.

I might for practical reasons not obey requests completely, but will try to do so if it is reasonably possible.

 

Here is an incomplete list in no particular order, beside grouping of the brands.

This is what I have in the testing pipe:

1. Steinheil München, Cassaron 40mm f/3,5
   
2. Steinheil München, Cassarit 45mm f/2,8
   
3. Steinheil München, Cassar S 50mm f/2,8
   
4. Steinheil München, Cassarit 135mm f/4.5
   
5. Steinheil München, Cassar 55mm f/3,5 enlarger lens
   
6. Enna München, Lithagon 28mm f/3.5
   
7. Novoflex, Noflexar 105mm f/3,5 bellows lens
   
8. Canon, EF 40mm f/2.8 STM
   
9. Canon, FDn 50mm f/3.5 Macro
   
10. Canon, FDn 100mm f/4.0 Macro
    
11. Canon, 20mm Macro Photo Bellows Lens
    
12. Leitz Wetzlar, Focotar 50mm f/4.5 from 1954
    
13. Leitz Wetzlar, Focotar 50mm f/4.5 from 1964
    
14. Leitz Wetzlar, Focotar 50mm f/4.5 from 1969
    
15. Leitz Wetzlar, Focotar 50mm f/4.5 LFE
    
16. Leitz Wetzlar, Focotar 60mm f/4.5
    
17. Leitz Wetzlar, Focotar II 100mm
    
18. Carl Zeiss, Luminar 16mm f/2.5
    
19. Carl Zeiss, Luminar 25mm f/3.5
    
20. Carl Zeiss, Luminar 40mm f/4.5
    
21. Carl Zeiss, Luminar 63mm f/4.5
    
22. Carl Zeiss, Zoom Luminar
    
23. Carl Zeiss Jena, Mikrotar 100mm
    
24. Nikon, EL-Nikkor 50mm f/2.8 old metal version
    
25. Nikon, EL-Nikkor 50mm f/2.8 new plastic version
    
26. Kuribayashi, Petri Orikkor 105mm f/3.5
    
27. Kyoei Optical Co, Acall 135mm f/3.5
    
28. Soligor, 135mm f/3.5
    
29. Galaxy, 135mm f/3.5
    
30. Industar, 50-2 50mm f/3.5
    

These will keep me occupied for quite some time.

Then I have more lenses from Novoflex and some different 35mm f/3.5 lenses, but no Kuri or Kyoei variants.

[StephanN]

Given the latest threads, perhaps the Steinheil München, Cassar S 50mm f/2,8 would be of particular interest

 

I'd like to see how the Canon, EF 40mm f/2.8 STM fares, I've got one at home and my gut-feeling tells me it's similar to the Cassar, at least in the upper UV-region. Would be instructive to see if I can trust my intestines.

 

 

 

[Edit]

I don't suppose you have access to one of the MTO mirror lenses? I got a 500 and 1000 years ago in order for compact reach (well, the 1000 is not that compact, but the 500 is pretty small for a 500mm-lens), and the 500 does transmit some UV.

[/Edit]

[StephanN]

P.S.: Great work Ulf !!!!!!

[dabateman]

StephanN,

Jonathan ran a complete spectrum of the Canon 40mm STM. I can't find it but I do see his first test here:

https://www.ultravioletphotography.com/content/index.php/topic/3406-lens-transmission-in-the-uv-latest-update/page__hl__%2Bcanon+%2B40mm__fromsearch__1

 

Mine is here, but this data only indicates the UV cut off of about 354nm:

https://www.ultravioletphotography.com/content/index.php/topic/3897-spectroscopy-fun-with-some-lens-tests/page__view__findpost__p__35575

 

 

Ulf,

Excellent I look forward to your analysis. I picked up a Milar 50mm f4.5 in RMS based on your data. Mine looks similar cutting off about 315nm ish. May not work for UVB but is strong into UVA.

[ulf]

Thanks Stephan,

 

I have done something even better for this comparison with a quick dual graph for those both lenses.

Eventually there will be comparison posts too in the UV Lens Data section, but these two are really not similar.

Obviously the EF 40mm is the red curve.

 

[ulf]

In general a proper formal comparison post in the UV Lens Data section is easier to compile than one for the individual lens, but I have not yet decided how to format such a post.

Consider this comparison above as a quick and dirty preview.

 

When formats are better established I might do comparison posts on request, but I would like to populate the section more first.

I will let you know when I am open for such requests.

[StephanN]

StephanN,

Jonathan ran a complete spectrum of the Canon 40mm STM. I can't find it but I do see his first test here:

https://www.ultravio...__fromsearch__1

 

Mine is here, but this data only indicates the UV cut off of about 354nm:

https://www.ultravio...dpost__p__35575

 

Thanks, so my gut feeling is so-so

 

In general a proper formal comparison post in the UV Lens Data section is easier to compile than one for the individual lens, but I have not yet decided how to format such a post.

Consider this comparison above as a quick and dirty preview.

 

When formats are better established I might do comparison posts on request, but I would like to populate the section more first.

I will let you know when I am open for such requests.

 

Wow, that would be swell, you know like the Schott-Excel file filter-comparisons, to have something similar with lenses. Of course, not expecting you to hand out all the detailed data, but talking interface, then you wouldn't have to compile comparisons by hand. As a matter of fact, thinking about it, should you ever consider self-publishing a simple booklet with your findings, single lens data and perhaps some comparisons, I'd be more than happy to shell out for it; well, one can dream, right?

[ulf]

Wow, that would be swell, you know like the Schott-Excel file filter-comparisons, to have something similar with lenses. Of course, not expecting you to hand out all the detailed data, but talking interface, then you wouldn't have to compile comparisons by hand. As a matter of fact, thinking about it, should you ever consider self-publishing a simple booklet with your findings, single lens data and perhaps some comparisons, I'd be more than happy to shell out for it; well, one can dream, right?

 

I have plans to export decimated lens transmission data in a format that could be posted into the Schott calculator as a custom filter.

That would help evaluation different lens - filter combinations.

[StephanN]

I have plans to export decimated lens transmission data in a format that could be posted into the Schott calculator as a custom filter.

That would help evaluation different lens - filter combinations.

 

[Andy Perrin]

Number 24 and 25, the EL-Nikkor 50mm/2.8 pair, would be of interest to me! I just got one of them. I am actually not sure which one. Mine has a black ring but it feels like anodized aluminum rather than plastic. The lens is labeled EL-Nikkor 1:2.8 f=50mm Nippon Kogaku with serial number 892144.

[ulf]

Number 24 and 25, the EL-Nikkor 50mm/2.8 pair, would be of interest to me! I just got one of them. I am actually not sure which one. Mine has a black ring but it feels like anodized aluminum rather than plastic. The lens is labeled EL-Nikkor 1:2.8 f=50mm Nippon Kogaku with serial number 892144.

Yours is an old style lens.

 

I think the Nippon Kogkau designation is the eldest variant of the old metal lenses. I have not tested the same version as you have, but next generation.

If you compare the two posts for the 80mm f/5.6 you'll see that there is a difference in transmission there too, even if both are rather good.

I do not intend to buy a Nippon Kogkau 50/2.8, just for testing

 

This is how the plastic version looks like:

https://www.ebay.com...T8AAOSw-JBgJiY~

That is really bad for UV, while the metal version is acceptable, but not sa good as the 80mm.

[Andrea B.]

I'm always interested in those 35/3.5 lenses, whatever you have even if they are not Kuri.

 

An ongoing Thank You to Ulf for undertaking this measuring effort. We will all benefit from it and I'm sure the information will be enjoyed and used by many hundreds of readers around the world.

 

(OK, I might be just a tiny little bit optimistic about that "hundreds of readers".... )

[bvf]

Given the latest threads, perhaps the Steinheil München, Cassar S 50mm f/2,8 would be of particular interest

 

 

I don't suppose you have access to one of the MTO mirror lenses? I got a 500 and 1000 years ago in order for compact reach (well, the 1000 is not that compact, but the 500 is pretty small for a 500mm-lens), and the 500 does transmit some UV.

 

 

Probably not much point doing the Cassar S - we all know it's going to be the best ...

 

As it happems, last week I bought a 500mm mirror lens to experiment with. I thought about the MTO, but decided to go for the Tamron SP500 instead (I think it's smaller and lighter, and reviews indicate it has better IQ - or I should probably say less bad IQ). I had thought about seeing trying it out in UV, but unfortunately it needs huge filters for the front (82mm) and there's not enough room to mount my UV filters at the rear. So for me it looks like visible and IR only (luckily I already had a set of cheap-from-China IR 82mm filters).

[dabateman]

Bernard,

I may have the same mirror as you. I think I have the first adaptall version, which was not optimized for macro. I don't remember it working that well for UV. But I never really got around to testing it properly. The back filter I think is 30.5mm and the front I have stepped down from 82mm to 72mm.

[OlDoinyo]

Some of those Maksutov-Gregorian type mirror optics have rear filter trays in addition to the front threads. They accept small drop-in filters.

[StephanN]

My MTO-500 has a front filter thread of 77mm,but no filter tray. I have wondered a couple of times whether it would be worth trying to get rid of all the lenses in the back because I've read that this the part where most of the UV is lost. Does anyone have experience with this? I've never done it because of my two left hands, I'll either break the lens or my fingers

[bvf]

Bernard,

I may have the same mirror as you. I think I have the first adaptall version, which was not optimized for macro. I don't remember it working that well for UV. But I never really got around to testing it properly. The back filter I think is 30.5mm and the front I have stepped down from 82mm to 72mm.

 

Sounds like you have the earlier version, the 55B. Mine is the later version, the 55BB, which has close-focus capability and nearish-macro capability of 1:3. It's also engraved for use with a 2x teleconverter to give near-macro of 1:1.5 - but the thought of trying to do anything realistic with a 1,000 mm lens (using the 2x) and en effective aperture of f/22 (allowing for the blocking effect of the front mirror) boggles the mind. And yes, the rear filter amount is 30.5mm screw-in: I had a quick look around for some suitable UV filters that might be cheap enough for an experiment but couldn't find any.

 

I haven't had a chance to try it out properly because the weather is not ideal, but initial tests indicate less than stellar IQ. The bokeh, which is not normally something I get excited about, is pretty horrible. But then all these drawbacks are well publicised, and for £100 I thought I'd have some fun with it.

[StephanN]

see https://www.ultravioletphotography.com/content/index.php/topic/3974-uv-at-the-zoo/ for some uv-shots with the 500

[bvf]

Some of those Maksutov-Gregorian type mirror optics have rear filter trays in addition to the front threads. They accept small drop-in filters.

 

I think that might apply to the MTO, but the Tamron is a Schmidt-Cassegrain design. The rear filters are 30.5mm screw-ins. Looks like you could stack a couple of these, but the Adaptall-2 converter prevents use of larger filters with stepping ring.

[ulf]

I will change the format of the names of lenses in the list in the first post to italic underlined ,when the data is submitted in the UV Lens Data section.

 

The only super-tele lenses I have suitable for UV are the long Novoflex-lenses.

They ate physically very long as they are true tele lenses. That gives extra inertia that helps stabilise the lens mechanically like a line dancer's pole.

Those lenses are really good for UV.

 

I have no mirror lenses that you have started to discuss above, to evaluate.

[dabateman]

I also have 200mm, 300mm and 500mm single fused silica elements. I tried the 500mm as a single element, but yes I needed a pole to focus it, but the image quality was quite horrible. Its much better in combination with the 200mm and 300mm to give a 112mm equivalent view. I should test others on their own. But my birds in UV idea has been derailed, as I don't have great place anymore to set up a tripod.

 

Ulf,

Sorry to shift the conversation around. We are excited to see the data values. Thank you for taking this on. I don't have the ability to properly scan a lens. I just get a general idea about its character.

[ulf]

No problem at all.

If there is an interest for UV-super tele lenses I could measure the absolute transmission for my long Novoflex lenses, but I already did an extended evaluation without that two years ago:

https://www.ultravio...__fromsearch__1

 

I have the graphs and pictures of the lenses ready, for many of the lenses in the list in the top post.

I just have to complete the texts to publish.

That alone is at least 1 - 2 hours of research and writing, for each lens.