Can't reduce the size, sure sony B) A biotar can perform better than a distagon (and vice versa) - it just depends on the skill of the designer.
Quote:Can't reduce the size, sure sony B) A biotar can perform better than a distagon (and vice versa) - it just depends on the skill of the designer.
Small M lenses don't work so well with mirrorless digital cameras because of the glass in front of the sensor. Leica's workaround is to use very thin glass (<1mm), Canon/Nikon/Sony are around 2mm. The solution seems to have a larger exit pupil.
http://www.lensrentals.com/blog/2014/06/...-it-matter
On the other side, the new Zeiss Loxia aren't that much bigger than ZM lenses but don't have that issue.
http://flickr.com/ephankim
Beg your pardon, but leave the "small lenses" to Leica owners who make it their holy grail to manual focus. I don't know of any "small" decent, fast AF lens, do you? For at least APS-C size?
A very lazy but very effective solution to fixing issues based on the coverglass is to complete the design then vary every radius of curvature with the new coverglass thickness. The optical path is very similar but the balance of astigmatism and spherical must be adjusted - often the optical design software will "smash" the new aberration and recover 90%+ of the old performance.
Quote:Beg your pardon, but leave the "small lenses" to Leica owners who make it their holy grail to manual focus. I don't know of any "small" decent, fast AF lens, do you? For at least APS-C size?
I have no problems with manual focus for static subjects on the A7 because of the focus peek.
Here are examples of my photos with Contax G lenses in Havana
https://www.flickr.com/photos/ephankim/s...216825095/
Back in the days when I had a Nex-6, I had good results with Sony 24/1.8 ZA, Sony 50/1.8 OSS & Sigma 19/2.8.
Reviews of the Sony 35/1.8 OSS, Sigma 30/2.8 & 60/2.8, Zeiss 12/2.8 & 32/1.8 are quite good too.
http://flickr.com/ephankim
Quote:A very lazy but very effective solution to fixing issues based on the coverglass is to complete the design then vary every radius of curvature with the new coverglass thickness. The optical path is very similar but the balance of astigmatism and spherical must be adjusted - often the optical design software will "smash" the new aberration and recover 90%+ of the old performance.
Who cares if it's lazy as long as it works
http://flickr.com/ephankim
Well in lens design the biggest questions are always:
* can it be done better
* can it be done simpler
and one related to the last one:
* can it be done cheaper
Designing e.g a 50mm f/1 autofocus-ready lens is reasonably doable, designing one with higher performance and that is economical for all parties involved is hard. Typically when someone says they want a design for _____________ complex/special lens (e.g 50/1) the answer is not "can't do" it's "you can't afford it."