Sudden slow download times


SGP, Win 7, and here are the SG logs.

I am using a Canon 60Da, and my usual download times with SGP is about 15 seconds. Last night and tonight it is over 3 minutes. I have tried swapping out USB cables with no luck. Strangely, it downloads (binned) auto focus images in the usual 15 seconds, but not the main image of the DSO. If I watch the screen as the download begins, at about the 15 second mark there is a “shift” in the screen. Nothing really changes, it is almost like the screen flickers at the time that it would usually be done the download, but it then continues for about 3 more minutes before finishing.



I have this happen with my Canon 70d. The active SGP module gives a message that it is not responding then waits for the image to finally download. The program then resumes normally and carries on with the sequence.



Sometimes this change in perceived download time is caused by turning on image history for large images on old computers.


I noticed something similar when I switched my file destination from the main computer to an external USB3 memory stick in a USB3 port. A soon as switched it to something else (even USB2), it worked as normal.


Unfortunately, you are right Ken. It is image history that is causing the slow download. I turned it off and the downloads went from over 3 minutes back down to the usual 15 seconds. Now this is a disaster of epic proportions. :slight_smile: I love image history, and really don’t want to have to stop using it, but 3 minute downloads are just too long to endure regularly. What I can’t understand is why is the problem only showing now? I almost always have image history on, and with the same equipment have not had this problem before now. The laptop I am using is two years old and has 4 G of RAM. Is there any way around this problem? Image history is an awesome tool that I’d really hate to lose.



The length of calculation is largely dependent on the area of the sky. Have you always been using a canon with it?

Beta clicking HFR takes forever now and almost freezescomputer

Ken - does image history have to complete before the next exposure is kicked off? Could it be that it checks to see if the exposures are a couple of minutes or longer and if so, completes its analysis during the following exposure?


It could, but that’s a feature request. It will also preclude any future possibility of taking any type of action based on this data.


@headdown I have added some code in 2.4.2 to possibly rectify this issue… either that or it will make it way worse. It essentially completes analysis on only a (centered) portion of the image (2500 px across).


Hi Ken,

Yes it is my usual camera, and there hasn’t been any other hardware changes lately.



Fantastic support as always Ken - thank you. I’ll let you know if it gets better or worse when I get the updated SGP.

I not only use image history to keep track of focus starting to drift, but it’s handy when I come back to the telescope the next night at a different temperature and need to find focus with the auto focuser. I can look at the image history data from the night before and see what the focus position was at the temperature that it is right now, and use that for my auto focus start point. It can eliminate the hassle of using a Bhatinov mask to get initial focus. Great feature that I’d hate to lose!



Ken I tried image history tonight and it is much improved. It now takes around 45 seconds to download and start to run the dither. Still a bit slower than I’d like, but not nearly as bad as it was. I will likely use it for longer subs where there are less total downloads.



I have noticed that the image file is created and shows in the folder but SGP still takes some time to complete the image history figures and start the next frame