Thanks all for your kind words!
turfpit wrote: ↑Sun Sep 01, 2019 1:08 am
Wickett
You must have been near sunrise to capture M42? Congratulations.
What is gain 300 as a % of max gain on that camera?
Dave
Sunrise was at 7:09 AM and the main M42 subs were captured at 15 seconds at 5:40 AM. The M42 core images were at 6.48 seconds at 6:14 AM. Really had to adjust the Live Stacking color balance as the pre-sunrise sky glow was taking it's tole. Used a Photoshop layer mask to combine the images.
The ASI294 unity gain is 120 that gives about 13 stops of dynamic range but at the expense of longer exposures. At 300 gain the camera still attains over 10 stops of dynamic range. Max gain on the SC scale is 550 but the data sheet from ZWO only goes to 400 gain with still gives 9 stops of dynamic range. This wide dynamic range along with 63700e full well makes for a very flexible camera. The 294 is by far my favorite for the type of imaging I do which is mainly live stacking and broadcasting on NSN. All this prattling on and the answer to the question is about 60% if you look at it as a liner scale.
umasscrew39 wrote: ↑Sun Sep 01, 2019 12:54 pm
I've not gone any higher than 4 with brightness - may have to experiment more with this as I am also Bortle 5 pushing 6 skies.
The way I determine the brightness (offset) value is to capture an image at the exposure and gain settings I intend to use. Since I've had plenty of the experience with the scope and camera combinations I have this is fairly easy to arrive at. While taking the exposure I'll have the Smart Histogram open and watch that the peaks of the histogram fall into the green range and that the range is off of the left edge of the histogram. I'll increase the brightness value to move the peaks without adjusting gain or exposure. These values will of course be different for scope, camera, filter and sky condition combinations.
Come over to NSN and check out folks broadcasting their astronomy journey. You'll find many users of SharpCap that are live stacking. Live audio and text communication and the broadcasters are more than happy to answer questions. We're constantly trying new techniques and discuss our shared hobby. Hope to see you all there!