Originally posted by lytrytyr By that token, transferred to our photographic discussion,
it seems as if Greg should be perceiving the FA 24-90 output as sub-standard,
since whatever its virtues, that lens is not noted for its build quality or superior feel.
I'm not saying all perceived differences are nothing more than perceptions. I'm just saying it is possible, that is all. And until you compare directly, you don't actually know. When I look at the same photo twice in a week, it may be that the first time I am content with the color or sharpness, but the second time, I am not. I don't think that has anything to do with my computer, I think it has something to do with the computer in my head.
By the way, judging lens performance from random photos posted by other people is hardly a reliable method. Differences in post-processing can also lead to visible differences, while the lenses themselves may not render so differently. Even the way the screens used by those respective users were calibrated at the time of PP can have an effect.
Originally posted by lytrytyr It is usually quantified by the 40 lp/mm MTF curve,
so resolution of very fine detail.
Ah, ok. Thanks for clarifying that.
Originally posted by lytrytyr The answer (I guess "no") matters to the relevance of Greg's argument.
Could be.
Originally posted by lytrytyr It's certainly not all physics.
Perception is closely tied to how human systems
(brains, ears, eyes, and the connections between them)
interpret physical signals,
so there is a lot of biology and psychology involved,
much of it not yet understood.
Several people have attempted to measure bokeh quality, for example,
but those attempts do not yet seem to be satisfactory.
I was talking about image quality, not the perception of image quality. My point is, everything that affects the image - and thus image quality - can be measured, in one way or another. It is light going through a number of glass pieces with certain refractive indexes and other properties (I'm no expert beyond the basics I got at high school, but I'm sure there are experts). Not everything that affects the
perception of image quality can be measured. Those are different domains.