07-06-2014, 05:00 PM
JoJu,
The shutter speed of the intial posted samples was 1/1600.
I believe that the diamond shape has nothing to do with shutter speed though. The diamond orientation rotates wrt. the center of the image (approximately) and I can't imagine how this should be related to shutter speed or the speed and direction of the drops.
I also did some further tests with different lenses. Interestingly, I also found that a different f1.4 lens shows simliar results like the sigma lens, both in terms of diamond-shaped bokeh in the field and magenta and greenish colors of drops in the center. Unfortunately I didn't find any good explanation (in the posts of this thread) for the diamonds. I wonder if it's just the shape of heavily vignetted ouf-of-focus spots or if the refractive power of the drops has something to do with it.
Attached is, what I'd have expected as "usable" bokeh btw. -- 70mm f2.8 1/4000. There's a little vignetting but apart from this it's quite usable.
The shutter speed of the intial posted samples was 1/1600.
I believe that the diamond shape has nothing to do with shutter speed though. The diamond orientation rotates wrt. the center of the image (approximately) and I can't imagine how this should be related to shutter speed or the speed and direction of the drops.
I also did some further tests with different lenses. Interestingly, I also found that a different f1.4 lens shows simliar results like the sigma lens, both in terms of diamond-shaped bokeh in the field and magenta and greenish colors of drops in the center. Unfortunately I didn't find any good explanation (in the posts of this thread) for the diamonds. I wonder if it's just the shape of heavily vignetted ouf-of-focus spots or if the refractive power of the drops has something to do with it.
Attached is, what I'd have expected as "usable" bokeh btw. -- 70mm f2.8 1/4000. There's a little vignetting but apart from this it's quite usable.