Category Archives: Resolution Tests

Sigma 24-35mm f/2 DG HSM Art MTF Curves and Sample Variation

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For years now, I've been telling people to always take the results of tests done on one copy of a lens with a serious grain of salt. Not matter how carefully it was tested, it's still just one copy. Others will be worse. Others will be better. Because I'm so aware of copy variation, I [...]

Sony a7R II Vs a7S Video Field Comparison

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The amazing low-light performance and ability to shoot in 4k has made the Sony a7S a definite favorite for our customers and the LensRentals team. We have been very excited over the release of the a7R II with new features such as 5-axis in-body image stabilization, a 42.4MP back-illuminated full-frame sensor, and in camera 4k. A few [...]

MTF and Variation: An Example

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We've spent most of the last month establishing a database of MTF curves and expected copy-to-copy variation for a number of lenses. Most people have a general idea about what we're doing, can follow along the basics of MTF curves, etc. But many other people also have a very good question, "How much of a [...]

Wide-Angle Zoom MTF and Variations

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We recently published the MTF and variation curves of standard range lenses and now are going to tackle wide-angle zooms. As we've seen, zooms have more variation than primes and wide-angle primes have more variation than standard range primes. Also, the MTF curves of wide-angle primes are weaker off-axis than standard range primes. So my [...]

A Quick Look at the New Sigma 24-35 f/2 Art

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Image Courtesy Sigma USA   I generally do MTF testing on multiple copies of a given lens so that I can present the averages, look at sample variation, and stuff like that. I'm always aware that looking at any single copy of a lens, especially a zoom lens, gives only a limited prediction of how [...]