I’d had really good luck with the Zony 55 (official name: Carl Zeiss 55mm f/1.8 Sonnar FE) on the a7R, and I expected superlative results on the less-demanding a7. Just to make things interesting, I compared the combination to the Leica 50mm f/1.4 Summilux-M ASPH on the M240. In some ways, it’s a fair comparison:… [Read More]

Using the methods described in this post, I computed the 14-bit Unity Gain ISO of the a7 at about 525, the 13-bit Unity Gain ISO at 1050, and the full-well capacity at about 86000 electrons. These are very good numbers. I’m a little suspicious, because the same tests gave unreasonably good results for the a7R,… [Read More]

How about the shadow areas in the bookcase pictures? I’m glad you asked. ISO 3200: ISO 1600: ISO 800: ISO 400: ISO 200: ISO 100:  

There are photographers who like to look at graphs and pictures, and many who just like to see pictures (I don’t think there are any photographers who just like to look at graphs). If you’re one of those people who just wants the pictures, the last post was probably unsatisfying to you. Read on. I… [Read More]

Yesterday I presented results that indicated that the a7 was “ISOless” using data made with strobe exposures at a shutter speed of 1/200 second. We have seen anomalies in noise floor measurements made at shutter speeds above 1/15. Therefore it seemed like a good idea to rerun the tests with a longer shutter speed. I… [Read More]