Schneider 28mm f2.8 Componon Perf Stacked is Extremely Good

RobertOToole · Post by **RobertOToole** » Sun Dec 30, 2018 4:12 pm

soldevilla wrote:Hi. What is the optical design of your assembly, Robert?
Macro Symmar is focusing to infinity and then you superimpose the Componon? It is assumed that an enlarger lens works best when the distance to the focus from the front and back is short ...
I already have some tests to do next year.

Makro-Symmar 120 at infinity and the 2.8/28 reversed and almost touching the front of the lens.

Its sharp at f2.8 but a tiny bit better at f3.1, half way between 2.8 and 3.5. f3.5 is softer. Corners are perfect at f2.8-3.1.

BR,

Robert

dmillard · Post by **dmillard** » Sun Dec 30, 2018 5:20 pm

ray_parkhurst wrote:Looks like that "Apo" lens will have some strong red hues when focused 200um high.

And even more in this "Apo" lens!

ray_parkhurst · Post by **ray_parkhurst** » Sun Dec 30, 2018 5:30 pm

dmillard wrote:
ray_parkhurst wrote:Looks like that "Apo" lens will have some strong red hues when focused 200um high.
And even more in this "Apo" lens!

Yes indeed. You can see real-world hue shifts at coinimaging.com:

http://coinimaging.com/lens_tests_new.html

Select repro/duplication lens pulldown and then the 75ARD1, and "miscellaneous" page, where the LoCA is shown. The lens shows a strong red hue OOF high, and strong green OOF low.