×

INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

FITS Viewer Optimization

  • Posts: 27
  • Thank you received: 4
Hello,

I would like to add a request.

Right now, this is the typical behavior that I am encountering:

- I plan a sequence of n pictures with x seconds of exposure and launch it - I have dithering set to every two exposures
- The first picture finishes acquiring and it's typically downloaded and displayed in 2.5s (the estimated time to download matches that, too) - so far, so good
- The second picture finishes acquiring, the dithering starts - but then, somehow, the estimated time to download gets increased by the presence of the dithering and the new estimate is now around 6.5s - and it stays like that for the rest of the session, also for the undithered frames

Also, I tried turning on the option "compute HFR" so that I can monitor the focus and decide when it's a good time to refocus, based on computed numbers. However, this slows down the images even more and the estimate becomes 8-9s.

Given that the next image doesn't start acquiring until the previous one it's downloaded, this is actually slowing down the whole acquisition: from a nice and fast 2.5s, if I have dithering - which I pretty much have to have - it goes to 6.5s and if I add HFR it goes to 9s. Now, it may not seem much, but when I take about 50 images in one night, it adds up.

2.5*50 = 125s (a little over two minutes wasted).
9s for every picture, means 9*50 = 450s. That's 7.5 minutes just on download times, or 5 minutes longer what it could be if I didn't have dithering or HFR enabled.

Now my questions:

- would it be possible to download the image and then issue the command to dither? That way the estimate for the download time would keep to a nice and constant 2.5s and not increase to 6.5 for all frames, whether I am dithering or not. I understand this would delay the beginning of dithering by the download time, but 2.5s is better than 6.5s - I don't know if this can be optimized even further and I understand that the capture program needs a confirmation that the previous image is complete before starting the next one, and downloading it is a pretty sure way that it is indeed finished. But the download times shouldn't be increased due to dithering
- would it be possible for the HFR to be computed by the FITS Viewer <strong>after</strong> the image is downloaded and displayed, such that it doesn't slow down the download time and increase the estimate as well? I have plenty of time while the next image is being captured to wait for the HFR of the previous one to be calculated and displayed. Even if I was using very short exposures (say 15-20s), if the difference between no HFR and HFR is 6s added to the download time, there's still a lot of time left while the next image is being captured
- better yet, would it be possible to compute the HFR manually, on request, only when the user requires it? This way, the download time wouldn't be affected at all, and I could ask FITS Viewer to compute the HFR while the next image is already being captured. I don't have an automatic focuser, so I need to be by my rig anyway and I could ask for the HFR every few pictures to see if it's increasing or staying pretty constant and judge when it would be a good time for a refocus. Right now I just refocus every hour, just because, or I have to look closely at each image until the stars "seem" to become bigger. But a mathematically computed number over the whole frame is much safer than trusting my own eyes

Thanks for taking this into consideration!
Matteo
Last edit: 3 years 2 months ago by Matteo Gaetan.
3 years 2 months ago #65451

Please Log in or Create an account to join the conversation.

Time to create page: 0.248 seconds