07-04-2014, 09:12 PM
Your "lawn sprinkler test" has two serious problems. fast moving drops and different light situations - some drops are in bright light, others in shadow. The third problem is only mine. Shooting a sprinkler at f/1.4 is a kind of testing which doesn't say much about the quality of a lens. Especially with a narrow DoF. Also we don't know about the shutter speed, I couldn't read the EXIF.
But maybe the Sigma is just not the best for shooting your sprinkler wide open, maybe you just need to get a very decent sprinkler lens ^_^ I'm sorry, I don't belong to the sprinkler-fanclub, I was just taking this one because I found the water surface nice. But even at 1/4000 the drops are not perfectly round. And I wouldn't expect from a lens which costs 23% (!) of the reference to be equal wide open. This is what the hype's about: it is close in some aspects, to me close enough, but it is not apochromatic. I do find it a bit weird: First get the top of the top notch lens and then compare any competitor. Do you need reasons to buy the Otus?
<p style="margin:0px 0px 0px 0px;">![[Image: _DSC4804-M.jpg]](http://sojujo.smugmug.com/Street-Scenes/River-cities/It-started-with-a-rainbow/i-VSHg5jh/0/M/_DSC4804-M.jpg)
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<p style="margin:0px 0px 0px 0px;">For drop-peepers larger version
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<p style="margin:0px 0px 0px 0px;">Could you show us the drops of the Otus, please?
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<p style="margin:0px 0px 0px 0px;">Here's another one from the same series showing the same phenomenon as yours. If the drops are very close to the camera, they show a rhomboid - so what? Important thing is, what does the lens show in the proper focus plane.
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<p style="margin:0px 0px 0px 0px;">I think the rhomboids are easy to explain. Same effect like in the old days when we found it creative to turn a zoom ring while the shutter was open. The drops out of the sprinkler come in a ballistic curve and are moving in space, not in a plane. So there are different "blur sources": the speed, the curve shape of the movement and the approach towards the camera which by itself increases the bokeh not constantly but increasingly faster. Most of us have seen the picture with the race car with oval wheels because of the shutter curtains movement, a bit of that we see here, too. Next time I visit those sprinklers here I'll take some different shutter speeds to see if my guess is completely off or not.
But maybe the Sigma is just not the best for shooting your sprinkler wide open, maybe you just need to get a very decent sprinkler lens ^_^ I'm sorry, I don't belong to the sprinkler-fanclub, I was just taking this one because I found the water surface nice. But even at 1/4000 the drops are not perfectly round. And I wouldn't expect from a lens which costs 23% (!) of the reference to be equal wide open. This is what the hype's about: it is close in some aspects, to me close enough, but it is not apochromatic. I do find it a bit weird: First get the top of the top notch lens and then compare any competitor. Do you need reasons to buy the Otus?
<p style="margin:0px 0px 0px 0px;">
<p style="margin:0px 0px 0px 0px;">
<p style="margin:0px 0px 0px 0px;">For drop-peepers larger version
<p style="margin:0px 0px 0px 0px;">
<p style="margin:0px 0px 0px 0px;">Could you show us the drops of the Otus, please?
<p style="margin:0px 0px 0px 0px;">
<p style="margin:0px 0px 0px 0px;">Here's another one from the same series showing the same phenomenon as yours. If the drops are very close to the camera, they show a rhomboid - so what? Important thing is, what does the lens show in the proper focus plane.
<p style="margin:0px 0px 0px 0px;">
<p style="margin:0px 0px 0px 0px;">I think the rhomboids are easy to explain. Same effect like in the old days when we found it creative to turn a zoom ring while the shutter was open. The drops out of the sprinkler come in a ballistic curve and are moving in space, not in a plane. So there are different "blur sources": the speed, the curve shape of the movement and the approach towards the camera which by itself increases the bokeh not constantly but increasingly faster. Most of us have seen the picture with the race car with oval wheels because of the shutter curtains movement, a bit of that we see here, too. Next time I visit those sprinklers here I'll take some different shutter speeds to see if my guess is completely off or not.