Have sharpcap follow and stack a target for a specific number of hours?

[Dale R.]

I am trying to find out how best to solve an idea. I am trying to stack while unattended. I looked at the Sequencer tab and I am dumb as a fence post, so it was Greek to me. Is there a way to: Track DSO (x) and stack (save stacked raw frames) for (X) hours, (or a specific time like 03:45) and then return the scope to home..and be done.

Right now, I am going to bed after deciding how many hours I can sleep before I need to wake up and go stop the program.. Usually before it gets too low, gets light out, or does a meridian flip. It would make my simple way of gather frames for an object "overnight" easy. Right now, I set an alarm on my phone/put in earbuds so as to not wake the wife when the alarm goes off/wake up /run outside and shut everything down (but I learned to keep the dew straps running!) If I sleep through the night, I worry the mount might do something bad. I am running iOptron Commander on a CEM40EC and a CEM70. I do have it set to stop at 15 degrees..but I do not know if I trust it..

[admin]

Hi Dale,

there isn't currently a simple way to do this sort of thing in SharpCap - you are right to look into the sequencer for a solution for this, but as you have worked out, that's 'Advanced' SharpCap usage and can be tricky to get started with.

One thing you could do to try to learn a bit about the sequencer is to start off with the 'Deep Sky Sequence Planner' - that has a much simpler way of specifying what you want SharpCap to do (what target to GOTO, what exposure to set, how many frames to capture, do you want to part the mount at the end, etc). Tick the boxes for the things you want to do and then press the 'Advanced Edit' button at the bottom. That converts the choices you have made for the Deep Sky Sequence Planner into a full sequence editor sequence, that you can then edit further. In particular, you could put the bulk of the generated sequence inside something like a 'Stop running these steps at <Time of Day>' or 'Stop running these steps when <distance> degrees from the meridian'. Then put the final actions (park the mount, etc,) outside the 'stop running these steps...' block and you are starting to get there.

Getting the automated meridian flip to happen is even more complexity I'm afraid - I do want to simplify this in the future. One relatively simple way would be to stop imaging before the meridian, wait enough time for the mount to reach the meridian and then have all the GOTO, Plate Solve, Capture steps again - the second set should goto the target beyond the meridian and be able to keep imaging until the time limit runs out.

With all of this I would suggest testing while you are watching what is going on first - set the first time out limit to be only 10 minutes in the future and check that SharpCap correctly stops at that point and then parks the mount. If you go for the meridian flip, set up on a target due to cross the meridian in half an hour and watch the sequence progress through imaging, stopping because it is near the meridian, waiting, re-GOTO target past the meridian, etc.

cheers,

Robin

[Dale R.]

Thank you for taking the time to answer this! I will give your suggestions a try. I need to just jump in!!

I appreciate this program!! It is the single most important thing I use in astrophotography and EAA!!

[lowenthalm]

Dale,

After reading your post, I thought it would be a good exercise to create a clean script that does what you describe, using all the latest features in the SharpCap sequencer. I have my own system of Python and sequencer scripts, but they are a lot more complicated to use and pretty specific to my setup.

The attached script is Version 3 of the resulting script. I have been working on it the last few days, putting the smoky, cloud, moony skies I have been suffering through to good use!

The script is designed to work with equatorial mounts, but with minor changes could even be adapted for use with Alt-Az mounts. It will activate guiding if you have it available, perform automated meridian flips, periodic auto-focusing (which can be disabled if you don't have an electronic focuser), both manual and automated targeting, and both time-termination and terminate at dawn functions. The .scs file is just a text file you can look at and change with a simple text editor, or in SharpCap's sequence editor. The .scs text file is fairly well documented with comments throughout targeted at the scripting newbie. The comments also include descriptions of many additional thing you can implement yourself as you grow to understand how sequence scripting works.

The script uses all the common sequencer language constructs, so will give you a good way of learning how scripting works. Comments at the top of the script describe the adjustments you need to make for your own setup and a checklist to follow when creating copies of the script setup to capture a specific target.

[lowenthalm]

In the comments at the beginning of the script I made a booboo and left in some old instructions - ignore (delete) the lines from "#OLD instructions:" up to but not including the line "# GUIDING customization:".

They are just comments and don't do anything, but they will confuse the human reader. They were instructions for an earlier version of the code that don't apply to the V3 version of the code.

[Dale R.]

Thank you!! I did mess around with my own VERY basic commands. I ran it on a very short test and it looks like it will work. I will look at yours. I will need to get more complex if I want to continue getting more data to process!!

Thanks!!!

[lowenthalm]

If you have any questions about the script, feel free to post them to this thread. I'll keep an eye on it in case you or someone else that might be interested in the script as a jumping off point has questions.