EXPOSITION OVER 240" IMPOSSIBLE

Discussions on extending SharpCap using the built in Python scripting functionality
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Stef
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EXPOSITION OVER 240" IMPOSSIBLE

Post by Stef » Sat Aug 22, 2020 12:35 pm

hi all guys, i have a problem with image capture with atik314E color and sharpcap pro. Unfortunately I am unable to capture images with exposures greater than 240 seconds, the image is lost. The camera supports unlimited exposures but the program does not acquire them. I tried to use short cables, use the 32bit version but unfortunately the problem remains. Exposures at 240 seconds take 23 seconds to transfer. I use a pc with 4gb of ram and win10 with sharcap pro 32bit. with other programs I am allowed to go beyond 300 seconds, why does sharpcap not allow me? I also tried with snapshots and live stack but nothing ... thanks to those who can help me, I would like to be able to continue using Sharpcap, I like

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admin
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Re: EXPOSITION OVER 240" IMPOSSIBLE

Post by admin » Sun Aug 23, 2020 8:37 am

Hi,

I wonder if the readout time increases again beyond that point? SharpCap waits 30 seconds beyond the exposure time and if the frame is still not ready then it assumes that something is going wrong and tries again. I will test with the 314L+ that I have here and probably extend the timeout to 45 seconds anyway to see if that resolves the problem.

cheers, Robin

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turfpit
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Re: EXPOSITION OVER 240" IMPOSSIBLE

Post by turfpit » Mon Aug 24, 2020 2:46 pm

Stef

I have an Atik 314E mono CCD camera. Capture laptop is i3, 500GB SATA2, 8Gb RAM, Win 10 64-bit, SharpCap 3.2.6383 32-bit, USB2 cable 2m long plugged into a USB2 port. Using ASCOM drivers 7.0.7.21162, from SetupAtikCamerasUniversal-4.2.0.3.zip dated 28/11/2017, ASCOM 6.4. A 16-bit FITS file is ~2.8Mb.

Tests:
  • Captured 2 dark frames at 240s exposure, success. A single frame took about 2s to transfer to disk.
  • Captured 300s dark frame, success.
  • captured 10m & 15m dark frames, success.

Atik314E-ASCOM-driver.JPG
Atik314E-ASCOM-driver.JPG (19.03 KiB) Viewed 462 times

2-file-capture.JPG
2-file-capture.JPG (55.74 KiB) Viewed 462 times


The file creation times have a 4m 2s difference - this implies a USB transfer of ~2s for the 4m exposure.

240s.JPG
240s.JPG (88.11 KiB) Viewed 462 times

300s.JPG
300s.JPG (78.63 KiB) Viewed 462 times

900s.JPG
900s.JPG (82.28 KiB) Viewed 462 times

What size are your files from the the OSC camera and what format are you using?
Maybe post some FITS detail from a shorter exposure and a capture settings file from a successful shorter exposure.

Robin: maybe an Atik specific section in Cameras is needed?

Dave

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Re: EXPOSITION OVER 240" IMPOSSIBLE

Post by admin » Mon Aug 24, 2020 8:23 pm

Hi,

definitely an Atik specific section is in order – I should probably add a few other brands of cameras well. :-)

I think yours works correctly Dave because you are using the Ascom driver for your camera. I've just been looking at this bug this evening and it was my own silly mistake in the code that talks directly to the Atik cameras that was causing longer exposures to timeout. I'll have a fix in the next update to SharpCap 3.2.

Cheers, Robin

Stef
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Re: EXPOSITION OVER 240" IMPOSSIBLE

Post by Stef » Fri Aug 28, 2020 12:03 pm

Thank you all for the answers, you are all very kind, sorry if I was absent but I was away for work ... Thanks Robin then I will wait for the update.
I am delighted with this.
thanks again to everyone :-) ;) ;) ;)

Stef
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Re: EXPOSITION OVER 240" IMPOSSIBLE

Post by Stef » Fri Aug 28, 2020 12:41 pm

Hi Dave, yes, you are absolutely right, I tried the Ascom drivers and I managed to go to 600 seconds with a 1.4 second file download ... I had never tried with Ascom drivers because there is no digital gain (very useful for targeting with shorter exposures) ... I had never tried with Ascom. However, it would be very nice to understand why with native drivers the download takes place in almost 30 seconds with the same format (fits) and of course the 240 second bug ... It seems that Robin has already understood the problem. Thanks Dave for the information you gave me, so I can start using it before the update :-)

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