Sigma 30mm arrived- tested on Nex 7 100% crops

Started Mar 30, 2012 | Discussions thread
mike kobal
Senior MemberPosts: 1,597Gear list
Re: f/22@Jay Ell
In reply to Jay Ell, Apr 7, 2012

Hello Jay, seriously, I would be very interested how you would apply deconvolution to those files? We all know how to use USM

Jay Ell wrote:

mike kobal wrote:

have to share this with you, sure didn't expect this lens to perform so well,
impressive from 2.8 to 11, sweet spot 4- 5.6,

Thank you for your effort.

Corners are not that great at any aperture. Some distortion. Center is nice. Overall a fine performance in this test for a lens this inexpensive.

diffraction starts to be a factor at 11, @16 still usable, but barely, 22 destroys the image,

Diffraction seems to outweigths optical flaws at f/8.

Regarding usability of the image - you seem to have a pixel centric approach to the image quality, thus your standard for image quality changes with the pixel count of the sensor. For example if the NEX-7 only had 5 million pixels, the f/22 would appear much crisper at 1:1 magnification on the screen, yet at the image level the 24 Mp NEX-7 image would be easily more detailed. At f/22 you can easily get fine A4 prints without excessive sharpening.

Even though pixel centric view for image quality is incorrect, I added some unsharp mask sharpening to the f/22 crop of yours:

(The original image above is (c) Mike Kobal.)

Deconvolution would have done a better job, but this is just a demonstration, so I didn't bother to go beyond USM.

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Copyright © Jay Ell

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mike kobal
photography (hand's on gear reviews on my blog)

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