Archives for 2015

In this post, we saw a pronounced self heating effect in the dark noise of successive 30-second exposures with the Sony a7RII. I repeated the test with the predecessor camera, the a7R, and found far less effect. A reader postulated that the difference might be lower thermal conductivity between the sensor and the camera chassis… [Read More]

In the previous post, we saw a pronounced self heating effect in the dark noise of successive 30-second exposures with the Sony a7RII. I repeated the test with the predecessor camera, the a7R. I set the camera’s shutter speed to 30 seconds, which is as long as it will go. I set the shutter mode… [Read More]

There have been reports of strong self-heating effects at long exposures with the Sony alpha 7R Mark II (a7RII). I mentally discounted them, because I didn’t know of a mechanism that would preferentially heat the sensor with the shutter open and the photodiodes sitting there back-biased and waiting to snag a passing photon. But the… [Read More]

A participant in the DPR Photographic Science and Technology forum challenged my — admittedly based on gut feel and experience — contention that, for critical focusing, it was more accurate to do it manually than with autofocus. I thought about it, and decided that I wanted to see some real data. I took a Sony… [Read More]