Surprising STEINHEIL f2.8/50mm lens for reflected UV photography V - Lewisia

I got this mentioned older lens, which was made decades ago by famous lens maker STEINHEIL . It is a possibly single coated, well made 2.8/50mm lens which attracted me, since it showed some good UV transmission which I have previously shown. Now today some outdoor shots at f11, light source was overcast sky. Target was a Lewisia cotylodon flower.

[click on image gets you a larger image]

VIS image using UV/IR Cut filter:
 

UV image using Baader-U filter:
 

Simulated butterfly vision:
 

Simulated bee vision:
 

Quadryptich of human vision, reflected UV, simulated bee and butterfly vision (left to right, top to bottom):
 


Lewisia has a visible UV pattern, its petal tips are UV bright around 385nm, its center is UV dark, so this gets quite nicely visible, also in simulated butterfly and bee vision using this astonishing lens.

I have written more about that flower HERE 

I have written about that used lens HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Surprising STEINHEIL f2.8/50mm lens for reflected UV photography IV

I had mentioned in my previous thread, that a few years ago I got an older lens, which was made decades ago by famous lens maker STEINHEIL . It is a possibly single coated, well made 2.8/50mm lens which attracted me, since it showed some seemingly good UV transmission when shining an 365nm UV LED beam through it. The surprise came when I had it under my spectrometer, revealing its high and deep reaching UV transmission.  I have already shown that it performs quite well using the Baader-U filter, and here now its performance using some even deeper reaching UV filters, using a 340nm shortpass and the IDAS 330nm filter.

[click on image gets you a larger image]

VIS image using UV/IR Cut filter:
 

UV image using IDAS UV filter (approx. 330-370nm) at f5.6:
 

UV image using IDAS UV filter (approx. 330-370nm) at f8:
 

UV image using IDAS UV filter (approx. 330-370nm) at f11:
 

UV image using IDAS UV filter (approx. 330-370nm) at f16:
 

UV image using 340nm UV filter (approx. 320-340nm) at f5.6:
 

UV image using 340nm UV filter (approx. 320-340nm) at f8:
 

UV image using 340nm UV filter (approx. 320-340nm) at f11:
 

UV image using 340nm UV filter (approx. 320-340nm) at f16:
 

VIS and UV (IDAS) image side-by-side both at f8:
 

VIS and UV (340nm) image side-by-side both at f8:
 

As I had mentioned before, it got pretty clear that this lens has a very high UV performance, as at 365nm it transmits around 75%. Its peak transmission with Baader-U filter attached is around 68% at 360nm. At shorter wavelengths it still has a very useful 56% transmission at 340nm and 22% at  320nm.

Before I had shown here, that stopping down has improved sharpness significantly, especially in reflected UV light using the Baader-U filter. Now it gets quite obvious, that this lens is also performing very well at even shorter wavelengths, making it a very useful lens for reflected UV down to 330-340nm at an optimal f8/f11 setting, especially since the image size deviation between visible and UV image is also only 1.3% there .

I have written about that lens more HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Surprising STEINHEIL f2.8/50mm lens for reflected UV photography III

I had mentioned in my previous thread, that a few years ago I got an older lens, which was made decades ago by famous lens maker STEINHEIL . It is a possibly single coated, well made 2.8/50mm lens which attracted me, since it showed some seemingly good UV transmission when shining an 365nm UV LED beam through it. The surprise came when I had it under my spectrometer, revealing its high and deep reaching UV transmission, no other normal lens so far showed. But some outdoor images taken with it revealed, that it cannot be used fully open at f2.8 due to lacking sharpness and definition. So here now some indoor shots done in a controlled environment, using a modified Xenon flash for high UV output.

[click on image gets you a larger image]

VIS image using UV/IR Cut filter:
 

UV image using Baader-U filter (approx. 320-395nm) at f4:
 

UV image using Baader-U filter (approx. 320-395nm) at f5.6:
 

UV image using Baader-U filter (approx. 320-395nm) at f8:
 

UV image using Baader-U filter (approx. 320-395nm) at f11:
 

UV image using Baader-U filter (approx. 320-395nm) at f16:
 

VIS and UV image side-by-side both at f8:
 

As I had mentioned before, it got pretty clear that this lens has a very high UV performance, at 365nm it transmits around 75%, very close to the Kuribayashi 35mm which has 80%. Its peak transmission with Baader-U filter attached is around 68% at 360nm.

At f2.8 however the resulting images did not look as sharp as wished for, but stopping down has improved sharpness significantly, especially in reflected UV light, which by its shorter wavelength in theory resolves approx. 1.6x more. It gets quite obvious, that this lens is a clearly excellent and very useful lens for reflected UV at optimal f8/f11, especially since the image size deviation between visible and UV image is a bare 1.3% only.

I will in the next thread show the deep(er) UV performance of this lens...

I have written more about this lens HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Surprising STEINHEIL f2.8/50mm lens for reflected UV photography II

I had previously mentioned that a few years ago I got an older lens, which was made decades ago by famous lens maker STEINHEIL. It is a possibly single coated, well made 2.8/50mm lens which attracted me, since it showed some seemingly good UV transmission when shining an 365nm UV LED through it. The surprise came when I had it in my spectrometer, revealing its high and deep reaching UV transmission, no other normal lens so far showed. Now some outdoor images taken with it, all at f2.8 to see if that lens speed could be used. Light was overcast sunlight.

[click on image gets you a larger image]

VIS image using UV/IR Cut filter:
 

UV image using Baader-U filter (approx. 320-395nm):
 

UV image using Baader-U filter (approx. 320-395nm) and 340nm shortpass filter stacked:
 

VIS image using UV/IR Cut filter:
 

UV image using Baader-U filter (approx. 320-395nm):
 

UV image using Baader-U filter (approx. 320-395nm) and 340nm shortpass filter stacked:
 

It got pretty clear that this lens has a very high UV performance, at 365nm it transmits around 75%, very close to the Kuribayashi 35mm which has 80%. Its peak transmission with Baader-U filter attached is around 68% at 360nm. Using that deeper 290-340nm UV filter which peaks at 334nm with 68% transmissing, it still has a 32% total transmission at its peak at 338nm.

At f2.8 however the resulting images do not look as sharp as wished for, so another test will have to reveal if stopping down will improve sharpness considerably.

I have written about this lens more HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Surprising STEINHEIL f2.8/50mm lens for reflected UV photography I

Quite a few years ago I got an older lens, which was made many years ago by famous lens maker STEINHEIL. It is a possibly single coated, well made 2.8/50mm lens which attracted me, since it showed some seemingly good UV transmission when shining an 365nm UV LED through it. The surprise came when I had it under my spectrometer, revealing its high and deep reaching UV transmission, no other normal lens so far showed.

[click on image gets you a larger image]

Today now the spectrometric results as one of the best performing "normal" lenses for UV, slso showing the transmissing with the Baader-U filter, as well as a 290-340nm filter:



It gets pretty clear that this lens has a very high UV performance, at 365nm it transmits around 75%, very close to the Kuribayashi 35mm which has 80%. Its peak transmission with Baader-U filter attached is around 68% around 360nm. Using that deeper 290-340nm UV filter which peaks at 334nm with 68% transmission, it still has a 32% total transmission at its peak at 338nm.

 A very useful lens for reflected UV this seems to be, but photographic tests still needs to be done...

I have written about this lens more HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Steinheil Cassarit 105mm vs UV-Nikkor 105mm for reflected UV photography

Today a comparison between the well known UV-Nikkor 105mm lens and the lesser known Steinheil Cassarit f4.5/105mm enlarger lens. I'm using a patterned Phalaenopsis flower for that comparison and my work horse UV filter, the Baader-U filter. Light source was an UV enhanced Xenon flash as well as a Nichia 365nm UV LED. All shots done at f8.

[click on image to see a larger one; UV-Nikkor is on the left, Steinheil Cassarir is on the right]

UV-Nikkor vs Steinheil 105mm: VIS image using UV/IR Cut filter and Xenon flash:
 

UV-Nikkor vs Steinheil 105mm: UV image using Baader-U filter (approx. 320-395nm) and Xenon flash:
 

UV-Nikkor vs Steinheil 105mm: UV image using Baader-U filter (approx. 320-395nm) and UV LED:
 


That Steinheil lens transmits down to about 330nm and at 365nm has about 65% transmission. It needs refocussing when used for UV and the focus difference VIS-UV is just 1.2%, which the corrected UV-Nikkor lens does not need.

This comparison shows, that the UV-Nikkor 105mm is very hard to beat, but this Steinheil lens does very well, especially when used with an UV LED, considering it being a simple triplet lens. Finding a longer focal length UV-capable lens is a hard thing to do, so that Steinheil seems to be rather useful!

I have written about other Steinheil lenses HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

Steinheil Quinon 152mm vs UV-Nikkor 105mm for reflected UV photography

Today a comparison between the well known UV-Nikkor 105mm lens and the hardly known Steinheil Quinon f2.8/152mm lens (this lens seems to be a prototype as a f2.8 Quinon is not known, not even in the Steinheil production list). I'm using a white Phalaenopsis flower for that comparison and my work horse UV filter, the Baader-U filter. Light source was an UV enhanced Xenon flash as well as a Nichia 365nm UV LED. All shots done at f11.

[click on image to see a larger one]

Steinheil 152mm: UV image using Baader-U filter (approx. 320-395nm) and Xenon flash:
 

UV-Nikkor 105mm: UV image using Baader-U filter (approx. 320-395nm) and Xenon flash:
 

Steinheil 152mm: UV image using Baader-U filter (approx. 320-395nm) and UV LED:
 

UV-Nikkor 105mm UV image using Baader-U filter (approx. 320-395nm) and UV LED:
 

Comparison, UV-Nikkor image scaled to fit Steinheil:
 


That Steinheil lens transmits down to about 340nm and at 365nm has about 35% transmission.

This comparison shows, that the UV-Nikkor 105mm is very hard to beat, but finding a longer focal length UV-capable lens is a hard thing to do, so that Steinheil seems to be rather useful!

I have written about other Steinheil lenses HERE.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos