150mm Takumar/Super Takumar Design

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In my field test of this lens I had suspected that the design was a common six element Double Gauss type. I was informed that it was a five element design by one of our members. It was described by him and I concluded it was a modified triplet similar to the 200mm Takumar. It is not. It is a modified Double Gauss that is quite similar to the 105. It has three elements in front with two elements in the rear. The performance of the 150 is in no way similar to the 105 however, with the 150 being much superior wide open. Thanks for the cross section Peter. SR

-- Steve Rasmussen (srasmuss@flash.net), October 01, 2000

Answers

It is interesting to note that one of sharpest lenses ever tested by Photodo was a five element Double Gauss. It was a Leica 90mm f/2.8 Elmarit-R. The 150 Takumar/Super Takumar uses a very similar design. May explain why the 150 is so sharp.

-- Steve Rasmussen (srasmuss@flash.net), January 22, 2001.

Paul, the ultimate test of any lens is wide open performance since stopping down will decrease aberrations and only diffraction and field curvature will remain. The 150 does very well wide open. This five element Double Gauss design is long proven and little design work is necessary to build one. Also, the area of glass to be ground/finished is small. Because of this, the cost is low. The only thing I don't like is the f/22 stop. It really needs f/45 like the new 90-180 zoom.

-- Steve Rasmussen (srasmuss@flash.net), December 22, 2001.

I'm a long time Pentax collector/user in 35 mm, but I'm quite new to 6x7. In my search for affordable first lenses, i've noticed that prices on the 150/2.8 are quite reasonable. However, I've seen some disparaging comments in regard to its sharpness. i was pleased to see that you seem to disagree. Is there any reason why this lens is less expensive than most other 6x7 lenses? Does it have any serious drawbacks?

-- Paul Stenquist (pnstenquist@earthlink.net), December 21, 2001.

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