Received my 12nm Ha filter the other week, so I"m rapidly getting addicted to Ha! Such beautiful regions revealed.
This is more an experiment rather than an image I'm proud of, especially as I (for some reason) only used 2 minute subs (by 12, at 3200ISO).
But the lower signals reveal some pretty mad hot pixels! Fortunately nicely controlled by application of darks.
First pic is the best I could rescue out of the data.
Second is the stack with use of 5 darks, significantly better than without, but sorely needing more data. Next time I hope to try 8 minute subs.
Last is the stack without use of darks. Yeuck!
Nonetheless I"m still enthralled by the huge swirls of nebulosity revealed in just the 2 mins. Hardly matching John's gorgeous image, but hey, it's 2 mins, not 40!
I"m eagerly awaiting JTW Astro's A7s cooling experiments, I'll be close to the first customer once they go into production and post some comparison shots. Will keep you informed.
I would be interested to see if this camera is actually as sensitive as they say, or if its large pixels simply undersample enough that it seems more sensitive. Either way, it looks like it will be a good performer.
I would be interested to see if this camera is actually as sensitive as they say, or if its large pixels simply undersample enough that it seems more sensitive.
The A7s is certainly proving to be a viable astronomy camera and I am looking forward to seeing how they perform with cooling. It's a shame that the large pixel size (8.4 micron) diminishes their usefulness at shorter focal lengths.
I've seen it in action and it most definitely is very, very sensitive in low-light conditions with very little discernible noise at the higher ISO settings. Apparently the A7s has the largest pixel size of any consumer DSLR and that is certainly attributable to it's sensitivity.
Hi Ross, no it's not cooled yet. A chap on FB has a cooled Central DS one, I'm following him closely. Looks very promising.
I will be trying 8 minute subs with Ha next, to see if the noise is more than offset by signal. Pixinsight says I can go to 35 mins, that's awhile away yet!
