Alf Beharie
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 p.1 #8 · Sigmatel Scalematic 135mm f1.8 test... | |
bob_dodds wrote:
Surprisingly sharp and yet soft, the impossible combination needed for flattering portraits.
I have a Spiratone, and two Raynox Polaris, all YS MC versions of that Sigma 135mm f1.8. I removed the mount parts down to the T2 42mm x .75mm thread and use either T2-to-M42 or T2-to-SA(Sigma). If we run into an older CS M42 ring, replacing the CS M42 part would have those older version lenses focus a little beyond infinity, I think, due to 0.16mm longer CS ffl. They frequently come with weird diameter T2 flanges, too, so I take that off and attach conventional T2 mount flanges to the T2 thread. One of them did not have an M/A switch so I superglued the aperture pin down, and then the aperture was fully manual(versus not working!).
Proprietary Sigma CS vs M42: http://photo.net/classic-cameras-forum/00QGou probably the basis for later ffl diff between PK and SA though again the mounts are otherwise the same.
http://www.pbase.com/pganzel/samigon_135mm_f18_on_maxxum_7d
"Named after the founder of the Sigma Optical Co, Michihiro Yamaki. Short for (Y)amiki (S)igma. An innovation of Sigma, lenses with the YS mount were imported under the Spiratone, Samigon, Rokunar, Accura and other brands"
Are there any preset versions with front diaphragm? http://photo.net/pentax-camera-forum/00PLY0 "Kent Gittings , Jun 10, 2008; 11:02 a.m...It[105 not 135!] is not a great lens. If it is a 1965 lens and preset it will NOT be a YS lens, just a T-mount one. All YS lenses have the aperture assembly in the rear so that those YS mounts with aperture control can function properly. The Vivitar series 1 105/2.5 Macro on the other hand is one of the finest lenses ever made. As a macro it will hold it's own against the best OEM lenses from any maker. And unlike some older lenses with inferior coatings it works superbly with DSLRs also. No noticable CA and sharp edge to edge with either FF or APS-C. For cameras with mounts compatible with older lenses, meaning Pentax and Nikon, I would choose it first over any other. This lens was built to Vivitar's design specs by Kiron who later sold it under their own brand as a 105/2.8 macro lens. It might have a pinch less resolution than the even more famous Vivitar series 1 90mm F2.5 Macro (Tokina built)(Photodo 4.0 vs. 4.1) but unlike the 90mm it goes to 1:1 without an adapter or the 2x macro-focusing teleconverter...As for the Spiratone lens the one bright feature is the preset diaphagm. These have superior bokeh to rear diaphragm lenses of similar quality. As a collector of older M42 and YS mount lenses (also the guru of the YS mount according to the official 3rd party lens site) I have a really old Pentax Takumar preset of 200/3.5 that has stunning bokeh in out of focus objects due to the front mounted 18 blade aperture. If you are interested I have a Spiratone 135/1.8 in YS mount with either a regular YS M42 or a Pentax ES version (open aperture meteing with a Spotmatic F, ES or ES II). This lens was made by Sun Optical for various marketing brands like Spiratone, Polaris, Acura, and others, with a YS mount. I have a Polaris one also. They are a little soft wide open so they make a decent portait lens. Has a huge 82mm filter size. Also have a 135/1.8 in Sigma XQ series which is also a YS but it is in Pentax K-mount. This lens is sharper with a 77mm filter. This lens was also available in a Spiratone model and one sold recently in M42 on Astromart. -Kent Gittings"
For a guru on YS lenses he does'nt seem to know much about the history of them 
I'm not sure about the older preset versions with 82mm filter threads but I'm sure that all the 135mm f1.8 lenses branded Spiratone, Polaris, Acura, Sun, Sigmatel and others with rear aperture dials and 77mm filter threads were all made by Sigma. I use a 3" deep Sonia brand 77mm metal lenshood on my Sigmatel as its the perfect hood for it. 
BTW, the YS mount is actually named after the creater of Sigma optical in Japan (the Y stands for Yamaki and the S stands for Sigma).
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