Originally posted by UlrichSchiegg I don't understand your comment, how it relates to what I have written.
Digital and film lens design and "recording" have principle design differences. Digital lenses are constructed more towards "telecentric" beam of light guidance and longer exit pupil compared to film lenses. Lenses designed towards telecentric optic get longer. Microlens-shifting in front of digital sensors is done to improve the edge performance, which wasn't needed for film because it could take light at an angle.
There is not much that can be read in the open literature about lens design, but this is some of the basics that you can find. Also that it is used for DSLR and not just the compacts.
I tend to look at what the lens does, not what it's designed for.
My favourite story as a point of illustration.
Al Cooper was hired as studio musician for Bob Dylans Hwy 61. He was hired to play guitar but Micheal Bloomfield was there and he was absolutely outclassed. So he sat down at one of the studio organs and started fooling around. He laid down a track that eventually became the lead riff in one of the songs. One of the other musicians complained "he's not even an organist". To which Dylan replied "Don't tell me who is and who isn't an organist."
So basically, unless you have some pretty convincing evidence of the superior performance of digital lenses over lenses designed for film, I see no useful purpose for such differentiation.
In a previous post I mentioned that the FA 50 macro outperforms the DFA 50 1.4 for edge to edge performance, even though it's a "designed for film" lens. If the notion you posted above is true, then I would assume you have some kind of empirical evidence showing it to be the case. After all, no one cares if designs have been altered for digital based on some special design criteria, if it makes no difference to the recording characteristics of a digital camera system,
I also don't pay much attention to the manufacturers resolution numbers, that are based not on testing but on running the designed lens through a computer analysis. I really don't care what they are designed for. I only care about how the lens performs in the field.
A good lens is a good lens. Most of us are still waiting for the digital lenses that will replace the 31 ltd and 77 ltd. That those lenses were designed for film, really doesn't cut is as photographic criticism. Who cares if they were designed for film, if digital designs haven't surpassed them? And in the comparisons I've seen, nothing in the big heavy Sigma art series that are designed for digital surpasses or even equals them.
Last edited by normhead; 01-13-2019 at 10:02 AM.