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overmywaders
Joined: 27 May 2009 Posts: 49
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Posted: Tue Jul 07, 2009 1:25 pm Post subject: Non-SMC triplets |
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overmywaders wrote:
I have been using some old triplets for UV work. In comparing them to SMC modern lenses, I find that they pass more visible light as well as more UV. Since coatings often increase the passage of light, I suppose the fewer glass interfaces account for the triplets' efficacy.
I use the following:
Schneider-Kreuznach Jsogon 40mm 4.5
Ludwig Meritar 50mm 2.9
CZJ Triotar 13.5cm 4.0
Isco-Gottingen Isconar 100mm 4.5
The Meritar and Isconar take in so much light that at night most of the town suffers a temporary brown out as incandescent bulbs yield to the Meritar's momentary black hole. At midday the street lights come on for a moment in a three-block radius of my camera, whenever I click the shutter. I've tried stopping the lenses down until they scream, but with no measurable effect. As I type, the town council is drafting an anti-triplet ordinance - restricting the use of triplet lenses to the hours of 1:00 am to 5:00 am.
Have others also encountered these problems. |
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Spotmatic
Joined: 18 Aug 2008 Posts: 4045 Location: Netherlands
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Posted: Tue Jul 07, 2009 1:31 pm Post subject: |
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Spotmatic wrote:
Yes, I think that walking in the sun without applying sunscreen could cook your brains. _________________ Peter - Moderator
Pentax K-5 + Pentax 645 + Canon 5D + Bessa RF 10,5cm Heliar, and a 'little' bag full of MF lenses. The lens list is * here *.
My fast 80s: Asahi-Kogaku Takumar 83mm f/1.9 - Super-Takumar 85mm f/1.9 - FA 77mm f/1.8 Limited - Cyclop 85/1.5 (Helios-40 innards) - Komura 80mm f/1.8 - Meyer Görlitz Primoplan 7,5cm 1:1.9 - Carl Zeiss Jena 80mm f/1.8 Pancolar - Canon 85mm f/1.8 S.S.C. - Canon 85mm f/1.2 S.S.C. Aspherical |
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kds315*
Joined: 12 Mar 2008 Posts: 16634 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Tue Jul 07, 2009 1:51 pm Post subject: |
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kds315* wrote:
Well, Reed,
no many here will understand what you talk about ....
An uncoated lens surface takes about 4% of light, so for a triplet (uncoated) that would be 6 x 4% = 24% so I honestly doubt the lights went off...
SMS shoudl reduce that to ca 0.3% per surface, so that would theroretically be 1.8% - BUT you won't hardly see any UV anymore...
Welcome here btw.! _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
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overmywaders
Joined: 27 May 2009 Posts: 49
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Posted: Wed Jul 08, 2009 10:57 am Post subject: |
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overmywaders wrote:
Klaus,
I am new here. Six months ago, if someone said "Manual Focus", I'd have assumed they were discussing a Mexican revolutionary. Now, after having to manually focus daily, I am a deep well of ignorance.
I do like the triplets, though. BTW, if I have a faux triplet (4 elements/3 groups) does the resin cement interface for the rear group require light transmission calculations for eight surfaces, six surfaces, or ten surfaces? |
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kds315*
Joined: 12 Mar 2008 Posts: 16634 Location: Weinheim, Germany
Expire: 2021-03-09
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Posted: Wed Jul 08, 2009 12:40 pm Post subject: |
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kds315* wrote:
overmywaders wrote: |
I do like the triplets, though. BTW, if I have a faux triplet (4 elements/3 groups) does the resin cement interface for the rear group require light transmission calculations for eight surfaces, six surfaces, or ten surfaces? |
The problem is the cement to glue the elements, it BLOCKS efficiently UV! _________________ Klaus - Admin
"S'il vient a point, me souviendra" [Thomas Bohier (1460-1523)]
http://www.macrolenses.de for macro and special lens info
http://www.pbase.com/kds315/uv_photos for UV Images and lens/filter info
https://www.flickr.com/photos/kds315/albums my albums using various lenses
http://photographyoftheinvisibleworld.blogspot.com/ my UV BLOG
http://www.travelmeetsfood.com/blog Food + Travel BLOG
https://galeriafotografia.com Architecture + Drone photography
Currently most FAV lens(es):
X80QF f3.2/80mm
Hypergon f11/26mm
ELCAN UV f5.6/52mm
Zeiss UV-Planar f4/60mm
Zeiss UV-Planar f2/62mm
Lomo Уфар-12 f2.5/41mm
Lomo Зуфар-2 f4.0/350mm
Lomo ZIKAR-1A f1.2/100mm
Nikon UV Nikkor f4.5/105mm
Zeiss UV-Sonnar f4.3/105mm
CERCO UV-VIS-NIR f1.8/45mm
CERCO UV-VIS-NIR f4.1/94mm
CERCO UV-VIS-NIR f2.8/100mm
Steinheil Quarzobjektiv f1.8/50mm
Pentax Quartz Takumar f3.5/85mm
Carl Zeiss Jena UV-Objektiv f4/60mm
NYE OPTICAL Lyman-Alpha II f1.1/90mm
NYE OPTICAL Lyman-Alpha I f2.8/200mm
COASTAL OPTICS f4/60mm UV-VIS-IR Apo
COASTAL OPTICS f4.5/105mm UV-Micro-Apo
Pentax Ultra-Achromatic Takumar f4.5/85mm
Pentax Ultra-Achromatic Takumar f5.6/300mm
Rodenstock UV-Rodagon f5.6/60mm + 105mm + 150mm
Last edited by kds315* on Wed Jul 08, 2009 6:46 pm; edited 1 time in total |
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Laurence
Joined: 26 Mar 2007 Posts: 4809 Location: Western Washington State
Expire: 2016-06-19
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Posted: Wed Jul 08, 2009 5:17 pm Post subject: |
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Laurence wrote:
overmywaders - I think you went in over your waders to cause the street lights to change.
In any case, funny story! Good to see you here! _________________
Assent, and you are sane;
Demur,—you ’re straightway dangerous,
And handled with a chain.
Emily Dickinson
Cameras and Lenses in Use:
Yashica Mat 124 w/ Yashinon 80/3.5,
CV Apo-Lanthar 90/3.5SL, (Thank you Klaus),
Pentax 645,
Flek 50,
Pentax-A 150
Pentax-A 120 Macro
Voigtlander Vitomatic I w/Color Skopar 50/2.8
Konica TC and zoom lenses (thanks Carsten)
Contax AX
Yashica ML 50/2
Yashica ML 35/2.8
Carl Zeiss Contax 50/1.4
Tamron Adaptall SP 17/3.5
Tamron Adaptall 28/2.5
Tamron Adaptall SP 300/2.8 LD (IF)
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overmywaders
Joined: 27 May 2009 Posts: 49
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Posted: Wed Jul 08, 2009 7:56 pm Post subject: |
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overmywaders wrote:
Laurence,
Great inventions and discoveries are often met with skepticism. I recall that my invention of the Pisscalator raised similar problems. See http://www.overmywaders.com/cblog/archives/89-The-Pisscalator-Illustrated.html
Klaus,
I did some checking. The 4 element/ 3 group lens I am referring to is old, and probably cemented with Canada Balsam, so transmission for my purposes - 340-400nm - should be excellent. Canada Balsam has approx. 90% transmission at 340nm+; but plummets almost straight down in the shorter wavelengths, reaching 0% transmission by 290nm.
I'm thinking that, since optical crown glass has an index of refraction of 1.5339 at 435.8nm and Canada Balsam has an index of refraction of 1.54; and they share almost the same transmission rate in high UVA, I can just consider the faux triplet as a true triplet, ignoring the additional interfaces. Does that make sense?
Thanks.
Regards,
Reed |
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