Sony NEX-7 Tests

[See Update/Part 2]

In early May I managed to get my hands on a Sony NEX-7 camera with a couple of lenses. On May 15 I recorded a video review with Frederick Van Johnson on This Week in Photo. Ultimately, I decided this would be a great small, mirrorless camera to complement my huge Nikon D3s and its lenses, so last week I ordered one from Sony. I spent half of this past Saturday shooting with the NEX-7 and its kit lens, an 18-55mm f/3.5-5.6 (about 28-85mm full-frame equivalent). But when I got home and transfered the images, I was disappointed in their sharpness, pretty much uniformly. Did I get a bad copy of the lens? Was the camera just not as good as I though when I had a review copy? I decided to run some tests.

I’m just getting started, but here are the initial results. I started with the kit lens set to 35mm and f/5.6. (Wide open at 35mm is f/4 on this lens.) For comparison, I used an adaptor to mount a Nikon prime lens to the Sony body — an AF Nikkor 35mm f/2 D. Finally, I used the same lens on my Nikon D7000, which has an APS-C sensor, the same size as in the NEX-7. I used the lowest  “normal” ISO on each body: 100 for the NEX-7 and 200 for the D7000. The results are below. Click the image to see it full-sized, 1:1.

My interpretation? The Nikon 35mm on the Sony NEX-7 body is sharper than Sony’s 18-55mm. No real surprise there. But both lenses are sharper on the NEX-7 than the prime on the Nikon D7000. Well, maybe that’s not really a surprise after all, since the D7000 is a 2+ year-old camera and uses an older Sony sensor that’s the same size as the NEX-7’s.

As for the final decision about the NEX-7, we’re not there. I still don’t have an explanation as to why this weekend’s images are so soft. Perhaps it’s because most were shot at 55mm. Or maybe it’s that I used ISO 200 most of the day. In any case, further tests are required to determine what’s going on here. Stay tuned.

 

4 thoughts on “Sony NEX-7 Tests

  1. Oops! You’re right, Kelly. My full-frame Nikons are ISO 200 native, and I just assumed my D7000 was as well. But I just checked — I should have used ISO 100 on the D7000 as well. I need to run more tests, so I;ll re-shoot that one, too. Thanks!

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  2. No problem Doug. I was just wondering if there was something I had missed about the D7000 ISO settings. Thank you for your update and testing.

    -Kelly

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  3. One other thing, I noticed a bit of green fringing on the D7000 results. This might indicate a tiny bit of front focusing. Are you using live view for focusing or the viewfinder? I found live view to have the most consistent focus on the D7000 other than manual focus. You might consider using manual focus, zoom in on live view and then, focus as well as you can. Anyways, not sure if any of that is relevant in your testing, but I found it was much harder to get consistent focus in my testing than I had expected. The NEX-7 is definitely a nice camera and if it requires less fiddling with focusing, then that’s a plus.

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