Measuring read noise is fine, but by the time you can see the read noise, the photon noise is usually pretty bad. In fact, for me, the photon noise is more important as a measure of practical image quality. Here’s a test that shows the combined effects of photon and read noise as a function of… [Read More]
Archives for July 2014
Focus peaking on the a7S
Although I’ve never liked it when the camera’s on a tripod, focus peaking has great potential with the camera handheld. That’s because it offers the chance to focus without zooming in and losing the context of he whole image, a. Also, if it’s sensitive enough, you should be able to focus at the taking aperture,… [Read More]
Zeiss 35mm f/2 Biogon ZM on the a7S
I need a break from the lens cap pictures. Let’s see how legacy glass does on the a7S. The Zeiss 35mm Biogon in the Leica M-series mount is a delightful little lens. Small, and with nice controls, it seems like it was made for cameras like the alpha 7 series. However, it is the toughest… [Read More]
Sony a7S RN vs ISO corrected for amplifier gain
There’s a way to look at read noise vs ISO setting that’s different than the curves I presented in yesterday’s post. It’s a bit less intuitive, but, if you can get your head around it, it can give useful insight into how the sensor works. Rather than presenting the standard deviation of the noise in the raw… [Read More]
Sony a7S read noise vs shutter speed.
I made a series of lens-cap shots on the a7S with the ISO set to 12K, the drive mode at single shot, and the shutter speed varied in 1/3 stop intervals from 1/8000 second to 8 seconds: Read noise stays fairly constant as the shutter speeds get longer until about 1/10 second, when it starts to… [Read More]
- « Previous Page
- 1
- …
- 6
- 7
- 8
- 9
- 10
- Next Page »