Hello-
I just bought a Sony (Zeiss) vario-sonnar 24-70mm f/2.8 ZA SSM lens and have been putting it through the ringer to see if I have a good sample or not. It is awful sharp even wide open, but my questions concern the bokeh of the lens. Now, I bought it mostly for landscape use, so Bokeh was not my primary concern, however, I find myself using it around the house for portraits and documenting the growth of my children more than for landscapes, and for this reason I DO care about the bokeh.
I have seen reviews out there that show pretty decent bokeh with the lens. But pretty much all of those reviews are close up pictures with distant backgrounds, minimal specular highlights, etc. I can get good bokeh out of a mirror lens if I choose the background right. My real world shooting situations are usually NOT taking pictures from 2 feet away, but from around 15 feet away, and not watching the background so carefully, but just trying to get my kids doing whatever they are doing that i think is worthwhile taking a picture of (by the number of pictures I take of them you would think I want to document every breath). The problem is this- when I shoot the occasional closeup I get nice bokeh in the background. When I shoot at 5-15 feet, I often get horrible rings of light as if I was shooting with a mirror lens. But not reliably so. I have even gone back to the same location to shoot the same scene again to confirm the bad bokeh and had fairly neutral bokeh the second time around. My point is, I don't get it. And I don't have any examples out there to compare to, other than the closeup shots on the web. But as I say, my closeup shots look fine, too.
I will attach 2 pictures to the message to show you what I mean-- 100% crops of bakground images. If the attachments don't work, here are the links:
http://www.bokehtests.com/temp/SAL2470ZAbokehcloseup.jpghttp://www.bokehtests.com/temp/SAL2470bokehclose.jpg[attachment=6339:attachment]
[attachment=6340:attachment]
Does anybody out there have this lens? Does anybody else have any issues with bokeh at medium focal distances? Can anyone post any pictures of bokeh in difficult conditions at medium focal lengths? If so I would appreciate it. I don't know if I got a bum copy of this lens, or if this is just the way it is in all samples.
I have also started the formal testing of bokeh on this lens. It is the first one that i have done so in any kind of scientific way, but it is very labor intensive and time consuming. For those interested, there seems to be a bokeh sweet spot in the center of the lens at a focal range of 5-10 feet and f/2.8 aperture, but the 10 foot focal length has HORRIBLE bokeh at the edge of the lens. Anyone interested can see the initial results (about half of what is needed on the 70 mm side, still have to do 50mm and 24 mm) of the testing at the following link:
http://www.bokehtests.com/Site/Sony_Zeiss_24-70_Bokeh.htmlAnyway, I would appreciate any help you might have for me. I have 30 days to return the lens, but I bought it on the 8th of April... need to decide SOON.
THank you all!
Klaus
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http://www.bokehtests.com