ASCOM DSLR usage

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astromusic
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ASCOM DSLR usage

#1

Post by astromusic »

Hi, I got the ASCOM driver for my Canon T1i(500D) DSLR from the CloudyNights forum post: https://www.cloudynights.com/topic/6574 ... th-a-dslr/

This seems to work really well in the "Preview" mode - it keeps clicking away and showing the preview frames properly (all well and great!)

It also works fine when I am trying to do Polar Align (I don't have the Pro license yet, so I can't do the final step, but the first two steps work fine, and it is able to "Solve" the stars with two frames 90 degrees apart, and give me an error estimate). Again, so far, so good!

However, what I can't get to work at all (and I have tried it on 2 different Windows 10 machines, same result) is the "Live Stacking" mode. When in this mode, the bottom status bar says "Memory: 3 of 3 frame buffers in use" (usually only 1 is in use), and then it just stops. ONCE in a while, it works fine, and stacks it, but this happens about 1 attempt in 10 (subjectively). I have tried to limit the Frame Rate to 1 per minute even (just to slow things down), but that doesn't help either. I have tried this on a real Windows laptop (4GB RAM), and on a VM on Mac as well (tried 4-5-6-8GB RAM allocation, no dice). With the higher RAM allocations, I tried the 64-bit version of SharpCap as well, but with similar or worse results.

Screen shot attached for when it stops. FWIW, the poster on CN replied to my posting there as follows:
This won't help you much, but I didn't have any trouble stacking with Sharpcap Pro, Windows 10 Pro, and a Dell T7500 workstation having a 12 core 3ghz 64bit processor and 72gb ram. I don't recall ever seeing SC use more than one memory buffer. Using 3 sounds like a good clue for someone who knows what that means (not me).
Can anyone here help further?
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admin
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Re: ASCOM DSLR usage

#2

Post by admin »

Hi,

Looking down at the bottom right of the screenshot you sent, I can see that it looks like there is a problem with the frames coming from the camera – they should be arriving every 15 seconds or so (or a bit longer to allow for download), but SharpCap has been waiting 47 seconds for a frame to arrive and it hasn't so far.

If you don't activate the live stacking feature, do the frames continued to work regularly and correctly for a large number of frames (20, 40, 100, etc), or do they just work for a few frames and then freeze anyway? If they do work reliably without live stacking, then keep an eye on the frame progress indicator at the bottom right when you enable live stacking and see if the frame stopped every time when you switch the live stacking feature on. That would be weird and I can't imagine quite why it would happen but it does seem to fit with the description of your problem so far. Obviously there's no need to wait for a clear night to test this out – it doesn't matter what images in the frames as far as this sort of test is concerned.

Cheers, Robin
astromusic
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Re: ASCOM DSLR usage

#3

Post by astromusic »

Thanks for replying, Robin.

Yes, if I don't go into the Stacking mode, it will happily click away for ever. Please see the first screenshot below, where I let it get to about 30 frames. The Buffer count stays at 1 of 3. Then, I clicked on the Live Stack button, and the buffer count quickly climbs to 3 of 3, and no clicking or stacking takes place, even when I wait a few minutes. Weird! Also, in this case, the progress bar at the bottom right didn't even show up (it did the last time). Please see second screen shot.
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astromusic
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Re: ASCOM DSLR usage

#4

Post by astromusic »

Is there any debugging output that I can enable to further troubleshoot this? I am willing to do work to get this working!
BlackWikkett
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Re: ASCOM DSLR usage

#5

Post by BlackWikkett »

Setting--> General Tab at the very bottom check "Record extra information in the log for troubleshooting"
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Re: ASCOM DSLR usage

#6

Post by admin »

Also, have a look in the log tab that you can see on the right-hand side of the live stacking area. That shows log messages that are related to the life stacking that sometimes do not rate as important enough to get into the main log.

I suspect that what is happening here is that some portion of the live stacking procedure is taking a very long time to calculate for the high resolution images that you are using. Normally this should be too much of a problem as I know people use this functionality for similar resolution Astro cameras.

If you have a SharpCap Pro license then try increasing the memory settings from their default values in the memory part of the settings dialogue. This may help a little by giving you more than three buffers available. Another thing that you can do to help is to save one or two frames from the camera in fits format and then share them with me via dropbox or a similar filesharing website and I can see if I can reproduce the issue here using those frames in the testing cameras.

Cheers, Robin
astromusic
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Re: ASCOM DSLR usage

#7

Post by astromusic »

Hi Robin,

Interesting... I installed SharpCap 3.2 (32-bit) on a different laptop with 8GB RAM, and for some reason, it allocated 11 frames by default! Do you know why this may be? With this allocation, it had absolutely no problems stacking - it briefly goes up to 4 of 11 frames used, then drops to 3 of 11, and keeps stacking.

However, on my other computer (also with 8GB RAM), it stubbornly sticks to the 3 frame limit.

I don't have the Pro license yet to experiment with. I intend to buy it, once everything is working to my satisfaction.
astromusic
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Re: ASCOM DSLR usage

#8

Post by astromusic »

OK, got it!

I need to go into the memory settings, as you said, and switch to Paged mode, and push the memory to the max 2G allowed under the non-Pro mode. This results in 11 frames being allocated, and everything seems to work smoothly, at least on the bench.

Now, I need to find some time to try it out under some clear skies!
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Re: ASCOM DSLR usage

#9

Post by admin »

Ah, excellent news.

Not quite sure why one of your PCs were stuck in low memory mode rather than paged mode, but the limitation to 3 frames available was probably what is causing the problem. Essentially of all of the frames available are already in use then the camera can't take any more images and may get stuck waiting for some memory to become available to take the next image and something else is waiting for the camera to send the next image and nothing at all happens. With your high resolution sensor from the Canon camera at high bit depth, the size of each frame is very large so you obviously get less in the same amount of memory then you would for a planetary camera.

Cheers, Robin
astromusic
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Re: ASCOM DSLR usage

#10

Post by astromusic »

I know the reason why one of them was stuck at the low frame - it's in a VirtualBox machine on a Mac, which was initially configured with 4GB RAM. I upped it to 8GB later, but looks like the parameters are fixed on first run. I even uninstalled and re-installed the program, but it still was there (maybe as Registry entries?). It was only when I saw your suggestion that I found out about this setting!
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