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50mm: AF Nikkor 1.8; SMC Pentax-A 1.7; Super-Takumar 1.4
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PostPosted: Fri Nov 09, 2012 5:26 am    Post subject: Reply with quote

copy and paste from camerapedia...
http://camerapedia.wikia.com/wiki/Radioactive_lenses

Lenses Tested Radioactive (by the author)Edit

Kodak Ektar 101mm f/4.5 (Miniature Crown Graphic camera) lens mfg. 1946
Kodak Ektar 38mm f/2.8 (Kodak Instamatic 814 camera) lens mfg 1968-1970
Kodak Ektanar 50mm f/2.8 (Kodak Signet 80 camera) lens mfg. 1958-1962 (3 examples)
Kodak Ektanar 90mm f/4 (Kodak Signet 80 camera) lens mfg. 1958-1962
Kodak Ektanar, 44mm f/2.8 (Kodak Signet 30, Kodak Signet 50, Kodak Automatic 35/Motormatic 35 cameras) lenses mfg. 1959-1969
Kodak Ektanon 50mm f/3.9 (Kodak Bantam RF camera) lens mfg. 1954-1957
Kodak Ektanon 46mm f/3.5 (Kodak Signet 40 camera) lens mfg. 1956-1959
Kodak Anastar 44mm f/3.5 (Kodak Pony IV camera)
Kodak Color Printing Ektar 96mm f/4.5 lens mfg. 1963

Lenses Reported Elsewhere As RadioactiveEdit

Canon FL 58mm f/1.2
Canon FD 35mm f/2.0 (versions from the early 1970's)
Canon FD 55mm f/1.2 S.S.C. Aspherical
Carl Zeiss Jena Pancolar 55mm f1.4 (measured at 2360 nSv/h)
Carl Zeiss Jena Pancolar 50mm f1.8 "Zebra"
Carl Zeiss Jena Biometar 80mm f2.8 "Zebra" "(Only P6 mount version )
Carl Zeiss Jena Flektogon 50mm f4 "Zebra" "(Only P6 mount version )
GAF Anscomatic 38mm f/2.8 (GAF Anscomatic 726 camera)
Industar 61 L/Z MC (L is for Lantan - radioactive element)
Kodak Aero-Ektars (various models)
Kodak Ektanon 50mm f/3.9 (Kodak Bantam RF camera)
Nikkor 35mm f/1.4 (early variant with thorium glass elements)
Olympus Zuiko Auto-S 1:1,2/55 mm (first version with thorium glass elements)
Olympus Zuiko Auto-S 1:1,4/50 mm (only first version "Silvernose" is Radioactive)
Pentax Super Takumar 35mm f/2 (Asahi Optical Co.)
Pentax Super Takumar 50mm f/1.4 (Asahi Optical Co.)
SMC Takumar 35mm f/2.0 (Asahi Optical Co.)
Super Takumar 35mm f/2.0 (Asahi Optical Co.)
SMC Takumar 50mm f/1.4 (Asahi Optical Co.)
Super Takumar 50mm f/1.4 (Only latest Version 2)
SMC Takumar 55mm f/1.8 (Asahi Optical Co.)
Super Takumar 6x7 105mm f2.4 (Asahi Optical Co.)
Yashinon-DS 50mm f1.7 (Yashica)
Yashinon 55mm f1.2 (Tomioka)
Leitz Wetzlar Summicron 5cm f/2.0 (M39)
Vivitar Series 1 28mm F1.9

Lenses with elements made of contaminated glassEdit

Some lenses of the 1960s have elements made of glass sorts which include small traces of radioactive rare-earth elements. Sometimes this accidental radioactivity causes a significant yellowing of these lens elements. Some users of such lenses reported in camera blogs that they healed the yellowing by exposing these lenses to the ultraviolet light of the sun. The procedure needs several days of sunny weather to have a positive effect. Lens elements with such yellowing radioactive impurity are in the following lenses:

Minolta MC W. Rokkor-SI 1:2.5 28mm (early variant, before radioactive glass impurity could be banned)
Minolta MC Rokkor-PG 1:1.2 58mm (early variant, before radioactive glass impurity could be banned)

The healing of yellowing by sunlight is also reported for some lenses with thorium glass elements, for example for the Nikkor 35mm f/1.4 lens and the Super Takumar 50mm f/1.4 lens..


PostPosted: Fri Nov 09, 2012 10:20 am    Post subject: Reply with quote

RAART wrote:
copy and paste from camerapedia...
http://camerapedia.wikia.com/wiki/Radioactive_lenses

Lenses Reported Elsewhere As RadioactiveEdit
..
..
SMC Takumar 55mm f/1.8 (Asahi Optical Co.)
..

That surprises me. I have the Super-Takumar and S-M-C Takumar versions of the 1.8/55 and they're both perfectly clear and obviously of different makeup compared to the Super-Tak 1.4/50, which always has a very slight yellowish tint. Maybe the SMC version is different, but I haven't heard of that before.

The last paragraph of that article is strangely and less scientifically worded, I think it might have been added by someone else. The radioactivity is not "accidental". Using Thorium in the glass recipe would obviously induce radioactivity and the designers would have been completely aware of that and considered it negligible risk.


PostPosted: Tue Nov 13, 2012 2:45 pm    Post subject: Reply with quote

peterqd wrote:
RAART wrote:
copy and paste from camerapedia...
http://camerapedia.wikia.com/wiki/Radioactive_lenses

Lenses Reported Elsewhere As RadioactiveEdit
..
..
SMC Takumar 55mm f/1.8 (Asahi Optical Co.)
..

That surprises me. I have the Super-Takumar and S-M-C Takumar versions of the 1.8/55 and they're both perfectly clear and obviously of different makeup compared to the Super-Tak 1.4/50, which always has a very slight yellowish tint. Maybe the SMC version is different, but I haven't heard of that before.




http://www.youtube.com/watch?v=TVjhuN5Wy28
http://www.youtube.com/watch?v=oL3D7FQTHXo

Wink

There are many radioactive lenses that are NOT yellowed by time. Radioactivity mostly change the colour of the organic glue(canadian balsam) that bonds the cemented lenses not the glass per say ....
Canadian balsam was stopped used in middle to late 70s....


PostPosted: Tue Nov 13, 2012 5:24 pm    Post subject: Reply with quote

The only two pentax lenses Ive had the yellowed glass problem were the 50/1.4 and 35/2 supertakumars.
The 55/1.8 is one of my favorite normals but I havent seen yellowing on that in the SMC version.


PostPosted: Tue Nov 13, 2012 6:42 pm    Post subject: Reply with quote

Keysersoze27 wrote:
peterqd wrote:
RAART wrote:
copy and paste from camerapedia...
http://camerapedia.wikia.com/wiki/Radioactive_lenses

Lenses Reported Elsewhere As RadioactiveEdit
..
..
SMC Takumar 55mm f/1.8 (Asahi Optical Co.)
..

That surprises me. I have the Super-Takumar and S-M-C Takumar versions of the 1.8/55 and they're both perfectly clear and obviously of different makeup compared to the Super-Tak 1.4/50, which always has a very slight yellowish tint. Maybe the SMC version is different, but I haven't heard of that before.




http://www.youtube.com/watch?v=TVjhuN5Wy28
http://www.youtube.com/watch?v=oL3D7FQTHXo

Wink

There are many radioactive lenses that are NOT yellowed by time. Radioactivity mostly change the colour of the organic glue(canadian balsam) that bonds the cemented lenses not the glass per say ....
Canadian balsam was stopped used in middle to late 70s....

Thanks - something else I've learnt. Wink


PostPosted: Tue Nov 13, 2012 7:25 pm    Post subject: Reply with quote

peterqd wrote:
Keysersoze27 wrote:
peterqd wrote:
RAART wrote:
copy and paste from camerapedia...
http://camerapedia.wikia.com/wiki/Radioactive_lenses

Lenses Reported Elsewhere As RadioactiveEdit
..
..
SMC Takumar 55mm f/1.8 (Asahi Optical Co.)
..

That surprises me. I have the Super-Takumar and S-M-C Takumar versions of the 1.8/55 and they're both perfectly clear and obviously of different makeup compared to the Super-Tak 1.4/50, which always has a very slight yellowish tint. Maybe the SMC version is different, but I haven't heard of that before.





http://www.youtube.com/watch?v=TVjhuN5Wy28
http://www.youtube.com/watch?v=oL3D7FQTHXo

Wink

There are many radioactive lenses that are NOT yellowed by time. Radioactivity mostly change the colour of the organic glue(canadian balsam) that bonds the cemented lenses not the glass per say ....
Canadian balsam was stopped used in middle to late 70s....

Thanks - something else I've learnt. Wink


You are welcome.

Apparently the Super Tak 1.8/55 is not radiactive but the later S-M-C and SMC ones are 100% . Can't comfirm about the K-mount one...

By the way 14 of the http://camerapedia.wikia.com/wiki/Radioactive_lenses are updated by me in the list including the SMC 55/1.8 one Very Happy