Originally posted by Jimfear I'm interested, how is this supposed to work? Now stopped down there could theoretically be a difference in sharpness caused by number of aperture blades, though I doubt it (but if you have some test or physics that can back it up I'm interested).
But in the example of the K50/1.2 and the A50/1.2 shot wide open they would have to be identical as the aperture blades are fully retracted, optically it is like shooting without aperture blades.
Came to think of one further question. Does this also apply to other focal lengths than 50mm's? That is that around 6-7 aperture blades produce sharper pics. than an 8-9 aperture blade lens?
I did some further contemplation and observation regarding that observation before. from what I had observed further, I don't think that it is not only a matter of number of aperture blades, but also optic design and coating as well. with these factors affect light transmission and rendering altogether.
I understand that when lenses are wide open, is the general notion that it is shooting without aperture blades, or is it? it does look like it if we are going to look at it using our naked eye. my feeling is, that inspite of the fact that both lenses are 1.2 and could had been similar in optical design, I do somehow doubt it due to the number of blades and quite shorter and lighter design of the other lens. such number of aperture blades would had been needed for that particular optical design in the area of light transmission and part necessity. I don't believe it was only left there just for bling or spinal tap connotation. I do think that at stop down, this added extra would have some different subjective rendering as well (probably around the sharpness and bokeh level).
it's too bad that I don't have the K version to make the comparison and I'm quite curious to find something unique or different in the images (similar subject) produced by the 2 lenses as well.
I do somehow hope I could find someone who has a "K" copy just for comparison and testing purposes. if not, maybe buy 1 for 50-100 bucks (200 I still might consider).
p.s. I might do some more extensive testing between 4 types of 50mm lenses under controlled setting.