Astrophotography - some problems
I have read a lot about the problems with Sony cameras being ` Star Eaters' . I have the original Sony A7s and i gather that there is no problems with exposures up to 30 seconds but if i used bulb mode then the star eater effect would take place
For 99% of the time i would be using less than 30 seconds for my Nightscapes, although i intend to use my Astrotrac which would allow longer exposures. With a 200 mm telephoto lens i currently can do 3 seconds without star trailing (500 Rule).
Even at 30 seconds would give me a lot better signal to noise ratio with this lens using the Astotrac. I could always change to the Nikon D610 for bulb shots if needed.
I thought about the Sony A7s II but this was not as good at high ISO as the Sony A7s, the upgrade was more for the video side, this is also affected by Star eating above 3.2 seconds due to firmware issues.
Any firmware upgrades cannot be reversed, so i am glad i never up graded mine. The Star Eater problem is down to the software spatial filtering designed to reduce noise in photos
This issue affects all recent Sony alpha mirror less cameras including the a600, a6300, a7s, a7R, a7, a7II, a7sII and a7RII, possibly other models as well. It has been discussed on many forums and individual blogs with many people contacting Sony direct asking for a fix for the firmware.
To test this out take an exposure at 5 seconds then turn to bulb and take another 5 second exposure and compare the two. This one in bulb mode will see stars lacking punch (Brightness) with the star eater effect.
As the nights are too light in Shetland i wont be able to try this out on my camera.
Don't forget to join us on facebook - send a request to join Shetland Aurora Hunter now has over 900 members