Please see the attached images. They are from Sony A7R and Sigma 50/1.4A @ F4. One is stacking of 12 3-minute exposures (bulb), and the other is 90 30-second exposures (non-bulb). The total exposure is slightly different, and this probably just compensates the excess of read noise in the 30-sec case. So the depth of these two images should not be that different.
You can clearly see that many faint stars are GONE in the 3-min exposures, and the core of the bright stars are also strongly suppressed in the 3-min exposures. Sony's star eater does not only only affect the cores of bright stars, but also faint stars.
To me, this is totally unacceptable. Given what I see here, I can't recommend Sony to ANY astrophotographers. It is just unacceptable.
I will have some struggling about whether to get rid of this camera or not. Good luck to other Sony owners.
Edited by whwang, 13 July 2015 - 07:12 PM.