I have been using both the A7S and A7RM2 with no problems using 10,12, 16mm. Those with the problem are doing panos at a 25% coverage. Also the Post Program, LR does something to get rid of dead and hot pixels upon import (and the most used program with PS). With Capture One and now Aurora I get more stars. Also I shoot with Noise Control ON, yes ON, with no problem all the way to 50 seconds with the Voigtlander 10mm. Also with the Mark 2’s and 3’s there is the option of bright monitoring that gives a different capture brightness to start with but way better without using it. With Bright Monitoring you get an dark night image like you get the A7S with the A7RM2. What needs to be talked about more is Bright Monitoring and ISO Invariance both for night shots. Just learn and know your gear and your programs. Want to get rid of blue stars use C1!!!!!