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Some strange UV lens...
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PostPosted: Wed Jul 22, 2020 10:58 am    Post subject: Some strange UV lens... Reply with quote
Well, there is a special story behind this lens I am going to present here. I got a lens donated for my work by a member here, a very kind and actually very touching story, as I never would have expected that...

So now on to this f4.3/172mm lens, which has a built in blue (?) filter in it [these are not my images, but from the donating member here...]



Now these are some quick test shots hand-holding filters in front of the lens: the blue image is what seemingly it was made for (projecting images to a fluorescent screen I'm guessing), then I took that internal filter out and did an UV shot using a 365nm UV LED (quite sharp image) plus using the Baader-U filter and then a visible light image with suitable VIS-filter (which shows the lens was not computed for that) - all shot wide open at approx f4.

#1


#2


#3


Here now the transmission of that lens: The RED line is the filter alone, the GREEN the lens alone, the BLUE as it came assembled with filter inside. Most likely it was designed to project images onto a fluorescent screen. That built in short pass filter makes me believe that. It is not really UV, but short wave blue, enough to stimulate visible fluorescence.




Again, I am very thankful for the thoughts and donating this lens to me! The one who this goes to knows...


PostPosted: Wed Jul 22, 2020 1:49 pm    Post subject: Reply with quote
Very nice. Enjoy Like 1 .


PostPosted: Wed Jul 22, 2020 2:00 pm    Post subject: Reply with quote
Like 1 Like 1 Congrats

Hey! That's my American Optical Co. #651 ruler! Oh, wait, mine is here! LOL

Edit: PS -- is there more information about your spectrum graph equipment on your web site?


PostPosted: Wed Jul 22, 2020 2:07 pm    Post subject: Reply with quote
Thanks guys!

visualopsins wrote:
Like 1 Like 1 Congrats

Hey! That's my American Optical Co. #651 ruler! Oh, wait, mine is here! LOL

Edit: PS -- is there more information about your spectrum graph equipment on your web site?


You mean the spectrometer system I do lens measurements with? It consists of an Ocean Optics USB4000 UV-VIS-NIR spectrometer, a UV-VIS Xenon stabilized Hamamatsu light source, an apochromatic condensor system (to get a thin parallel beam) and an Ocean Optics integration sphere to collect really all light exitinf the measured lens


PostPosted: Wed Jul 22, 2020 2:16 pm    Post subject: Reply with quote
kds315* wrote:
Thanks guys!

visualopsins wrote:
Like 1 Like 1 Congrats

Hey! That's my American Optical Co. #651 ruler! Oh, wait, mine is here! LOL

Edit: PS -- is there more information about your spectrum graph equipment on your web site?


You mean the spectrometer system I do lens measurements with? It consists of an Ocean Optics USB4000 UV-VIS-NIR spectrometer, a UV-VIS Xenon stabilized Hamamatsu light source, an apochromatic condensor system (to get a thin parallel beam) and an Ocean Optics integration sphere to collect really all light exitinf the measured lens


Nice! Oh no! Now my GAS is acting up...

Thank you!


PostPosted: Wed Jul 22, 2020 2:31 pm    Post subject: Reply with quote
Interesting lens Klaus, thanks for sharing.


PostPosted: Wed Jul 22, 2020 5:55 pm    Post subject: Reply with quote
kds315* wrote:
Thanks guys!

visualopsins wrote:
Like 1 Like 1 Congrats

Hey! That's my American Optical Co. #651 ruler! Oh, wait, mine is here! LOL

Edit: PS -- is there more information about your spectrum graph equipment on your web site?


You mean the spectrometer system I do lens measurements with? It consists of an Ocean Optics USB4000 UV-VIS-NIR spectrometer, a UV-VIS Xenon stabilized Hamamatsu light source, an apochromatic condensor system (to get a thin parallel beam) and an Ocean Optics integration sphere to collect really all light exitinf the measured lens


Sounds very intriguing! If you had some comparable lenses (such as 50mm F1.4's) from different brands of the same period, and also any early coated lenses (thinking just post-WW2) - or even early coated binoculars - it would be very interesting to see if any understanding could be gained from comparing their results on the spectrometer, to see the transmission curves of their coatings. Even tests of different polarising filters could be interesting as most people assume them to work the same and be of equal quality.
I guess such a system runs into several thousands of dollars quite quickly. Are there any affordable units that would be suitable for a hobbyist?


PostPosted: Wed Jul 22, 2020 9:19 pm    Post subject: Reply with quote
Teemō wrote:
kds315* wrote:
Thanks guys!

visualopsins wrote:
Like 1 Like 1 Congrats

Hey! That's my American Optical Co. #651 ruler! Oh, wait, mine is here! LOL

Edit: PS -- is there more information about your spectrum graph equipment on your web site?


You mean the spectrometer system I do lens measurements with? It consists of an Ocean Optics USB4000 UV-VIS-NIR spectrometer, a UV-VIS Xenon stabilized Hamamatsu light source, an apochromatic condensor system (to get a thin parallel beam) and an Ocean Optics integration sphere to collect really all light exitinf the measured lens


Sounds very intriguing! If you had some comparable lenses (such as 50mm F1.4's) from different brands of the same period, and also any early coated lenses (thinking just post-WW2) - or even early coated binoculars - it would be very interesting to see if any understanding could be gained from comparing their results on the spectrometer, to see the transmission curves of their coatings. Even tests of different polarising filters could be interesting as most people assume them to work the same and be of equal quality.
I guess such a system runs into several thousands of dollars quite quickly. Are there any affordable units that would be suitable for a hobbyist?


This IS the affordable solution!! Wink Well, a little less if using a USB2000 (which I had before)...


PostPosted: Wed Jul 22, 2020 10:22 pm    Post subject: Reply with quote
Congratulations on the lens, and thanks to the benefactor.


PostPosted: Wed Jul 22, 2020 10:56 pm    Post subject: Reply with quote
kds315* wrote:
Teemō wrote:
kds315* wrote:
Thanks guys!

visualopsins wrote:
Like 1 Like 1 Congrats

Hey! That's my American Optical Co. #651 ruler! Oh, wait, mine is here! LOL

Edit: PS -- is there more information about your spectrum graph equipment on your web site?


You mean the spectrometer system I do lens measurements with? It consists of an Ocean Optics USB4000 UV-VIS-NIR spectrometer, a UV-VIS Xenon stabilized Hamamatsu light source, an apochromatic condensor system (to get a thin parallel beam) and an Ocean Optics integration sphere to collect really all light exitinf the measured lens


Sounds very intriguing! If you had some comparable lenses (such as 50mm F1.4's) from different brands of the same period, and also any early coated lenses (thinking just post-WW2) - or even early coated binoculars - it would be very interesting to see if any understanding could be gained from comparing their results on the spectrometer, to see the transmission curves of their coatings. Even tests of different polarising filters could be interesting as most people assume them to work the same and be of equal quality.
I guess such a system runs into several thousands of dollars quite quickly. Are there any affordable units that would be suitable for a hobbyist?


This IS the affordable solution!! Wink Well, a little less if using a USB2000 (which I had before)...


The light source costs $$$-$$$$ too! Whole system about same as good camera. Folks with access to university and/or corporate labs may find comparable equipment.


PostPosted: Thu Jul 23, 2020 3:38 am    Post subject: Reply with quote
Bravo, Klaus! Glad to see the great images you pulled out of this lens! BTW, the ruler was my father-in-law's. He worked his whole life in the research optical shop at AO in Southbridge, MA. He recently passed away.

All the best,

Paul


PostPosted: Thu Jul 23, 2020 7:34 am    Post subject: Reply with quote
visualopsins wrote:

The light source costs $$$-$$$$ too! Whole system about same as good camera. Folks with access to university and/or corporate labs may find comparable equipment.

Yes the source for the UV/vis spectrometer at work cost ~£450 an lasts on average about 18 months.
I make use of the spectrometer for looking at some of my photographic kit it works well for most filters (the sample beam is partly polarized so it's not ideal for polarizing filters) but as it lacks an integrating sphere it's not so good for lenses.


PostPosted: Thu Jul 23, 2020 8:00 pm    Post subject: Reply with quote
pdccameras wrote:
Bravo, Klaus! Glad to see the great images you pulled out of this lens! BTW, the ruler was my father-in-law's. He worked his whole life in the research optical shop at AO in Southbridge, MA. He recently passed away.

All the best,

Paul


Thanks again Paul for your generous donation and my sincere condolences to the passing of your father-in-law!
I'm sure he would have been a wealth of information on lenses!
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