Not strictly a newbie. Been using SC for polar alignment for a while and then switching to APT for image capture and mount control. Ive had my ASI1600MM since last November and I've had some decent results with unity gain so I've not changed it. I imaged M42 in February and I shot 2 hours of L and an hour each of RGB all at 30s subs. I got a pleasing image out of the data, even started to pick up some of the faint outer brown dust. So I started on another project in March. M81/M82 area. I shot 15 hours of 30s subs! I expected nice clean masters after stacking but I was left disappointed tbh. They are quite noisy. I can probably cobble something together out of the data but it's a lesson learnt. The difference between the M42 and M81 projects are the M42 was shot at F4.6 (WO GT71 x0.8) and M81 at the scopes native F5.9. So I believe I've under exposed. I clearly need to experiment with the available gain of this camera. I seen Robin's excellent presentation video from the PAS so I thought I'd give SC a go. I ran sensor analysis yesterday and got setup late last night for an unexpected clear spell. I choose M13 as a target and measured the sky. Cant remember the sky measurement but it recommended 75s subs at gain 59 and image brightness of 5. I choose 3% limit on read noise. I managed 39 x 75s subs at these settings between clouds. What came as a complete surprise to me was when I came across the settings tab and discovered SC can control the mount, filter wheel and focuser! I honestly didn't know this! So I got to grips with these as well, just having a play really. Got platesolving to work as Astrometry is already installed on the hard drive. The focusing routine is similar to APT so managed to work with that also. So next night out I'm going to hand everything to SC for full session!
A few questions.
Image brightness: is this another term for the cameras black point/offset?
Focusing backlash: I've measured my focuser backlash as 23 steps (0.05mm). In APT there is an input tab for this. So if I'm focusing out and then want to focus in 10 steps, the backlash will be added and the first movement in will be 33 steps. Is there the ability to do this in SC? If I scan out and then manually move back in 23 steps before starting scan in, will this mess up the tools best measurement?
Looking forward to the next night out with SC again. Will take a while I suppose to get a feel for the optimum settings to tailor for my sky conditions. For the time being I will just apply the recommended settings for each filter.
I've attached a quick process of M13 from last night. Nothing special, only Lum but I was impressed by how noise free it was for only 50 mins integration. Propeller is just visible, I think!!
David
- 20190505_175617-2728x1986.jpg (919.23 KiB) Viewed 998 times
