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]
Archives for February 2014
Sony a7 noise at slow shutter speeds
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]
Is the Sony a7 ISOless?
With the noise floor and self-heating testing out of the way, we’re ready to tackle the question, “Is the a7 ISOless?” If that question makes no sense to you, hang in there. Explanations follow. If you’ve read this or a similar explanation before, skip to the graphs. Let’s talk a bit about how your camera… [Read More]
Sony a7 noise floor in continuous mode
All of the histograms in the preceding post were made with the drive mode in single shot. When you put it in continuous, you get something different: ISO 100: ISO 200: ISO 400: In each case, only every fourth bucket has data. The pattern is the same at other shutter speeds and ISOs. In single… [Read More]
Sony a7 noise floor
Here’s the average value of the standard deviation of noise floor in the central 90% of the image vs ISO at 1/30th second: If the amplifiers and the analog to digital converters in the a7 were perfect, and all the read noise came from the sensor array itself, then the read noise would double every… [Read More]