Re: ToupTek usage with SharpCap
Posted: Sun Oct 08, 2023 7:50 pm
Thanks for the update on the 'advanced' DirectShow driver!
## tl;dr;
DirectShow driver currently seems to work better than ASCOM for everything except possibly Binning.
## Background
I had first light on my new OGMA AP26MC Monochrome IMX571 sensor with SharpCap Pro Beta 4.1.11069.0 02 October 2023 build last night imaging good old Andromeda Galaxy. I was shooting luminance in windy conditions and poor seeing with no guiding so wanted short subs. I use Live Stacking with the *amazing* "poor man's" dithering and drift correction features to keep my rig lean. I save all the frames and stack thousands of short subs offline in Siril the next morning on my Linux desktop for final processing.
## Issues with ASCOM driver
The smart histogram suggested about 3 seconds in my Bortle ~5.4 site. However, the ASCOM driver introduces almost 1 second delay in-between each frame captured. You can even see the timer in the bottom right corner go to negative after every frame. This latency was present regardless of the driver settings or exposure duration. I tried multiple known-good USB cables with no change. Using 2x2 binning reduced the issue somewhat, but not completely. So probably the ASCOM driver has to copy the data somehow with an implementation that wastes valuable photon grabbing time. As such I used longer 5 second subs to reduce the loss. My file timestamps show me imaging for 3 hours 6 minutes and 36 seconds wall clock duration. There are only 1779 sub files for a total integration of 2 hours 28 minutes 15 seconds. So roughly 20% of time lost due to ASCOM driver inter-frame-latency (assuming minimal time spent dithering and settling).
## Success with DirectShow driver
This morning I found this thread and did some tests. I installed the latest DirectShow OGMA "AP26MC" driver and for my purposes it seems to do everything better than the "ASCOM OGMAVision Camera" driver.
1. It captures at the expected published framerates for the given settings with no wasted latency between frames.
1. It captures at the correct published resolution MONO16@6224x4168 instead of some odd MONO16@6216x4152
1. The extra functions are integrated in SharpCap and seem to all work (Cooler works great, can even change the dew heater level too, black level offset easier to tweak).
The only issue I've found is that the Sensor Analysis crashes towards the last steps when it starts changing the Binning settings. I repro'd the bug and filed the 2x reports already.
## Conclusion
I'm soooo happy to find that the latest DirectShow driver will let me efficiently shoot short subs for Live Stacking!!! It feels almost as good as native SDK driver support. My only gripes with it are that the 'old' DirectShow driver seems to still appear as an option in the Camera menu with the exact same name as new new good one. I tried it and it only had RGB32 which immediately looked wrong with my mono sensor. I'm not worried about Binning except to complete a valid Sensor Analysis with this driver. I can't tell for sure if it is indeed USB 3.0 or not, but the framerate is fast enough for "Lucky DSO" and I have a different planetary camera for the real fast stuff anyway.
Cheers and clear skies!
-John Leimgruber "ubergarm"
## Screenshot Attachments
* DirectShow OGMA "AP26MC" driver working great maxing out published FPS on low noise mode.
* DirectShow "ASCOM" driver set to 10s subs showing slower than expected FPS.
* SharpCap Camera Menu showing two identically named DirectShow drivers and which one is "good".
## tl;dr;
DirectShow driver currently seems to work better than ASCOM for everything except possibly Binning.
## Background
I had first light on my new OGMA AP26MC Monochrome IMX571 sensor with SharpCap Pro Beta 4.1.11069.0 02 October 2023 build last night imaging good old Andromeda Galaxy. I was shooting luminance in windy conditions and poor seeing with no guiding so wanted short subs. I use Live Stacking with the *amazing* "poor man's" dithering and drift correction features to keep my rig lean. I save all the frames and stack thousands of short subs offline in Siril the next morning on my Linux desktop for final processing.
## Issues with ASCOM driver
The smart histogram suggested about 3 seconds in my Bortle ~5.4 site. However, the ASCOM driver introduces almost 1 second delay in-between each frame captured. You can even see the timer in the bottom right corner go to negative after every frame. This latency was present regardless of the driver settings or exposure duration. I tried multiple known-good USB cables with no change. Using 2x2 binning reduced the issue somewhat, but not completely. So probably the ASCOM driver has to copy the data somehow with an implementation that wastes valuable photon grabbing time. As such I used longer 5 second subs to reduce the loss. My file timestamps show me imaging for 3 hours 6 minutes and 36 seconds wall clock duration. There are only 1779 sub files for a total integration of 2 hours 28 minutes 15 seconds. So roughly 20% of time lost due to ASCOM driver inter-frame-latency (assuming minimal time spent dithering and settling).
## Success with DirectShow driver
This morning I found this thread and did some tests. I installed the latest DirectShow OGMA "AP26MC" driver and for my purposes it seems to do everything better than the "ASCOM OGMAVision Camera" driver.
1. It captures at the expected published framerates for the given settings with no wasted latency between frames.
1. It captures at the correct published resolution MONO16@6224x4168 instead of some odd MONO16@6216x4152
1. The extra functions are integrated in SharpCap and seem to all work (Cooler works great, can even change the dew heater level too, black level offset easier to tweak).
The only issue I've found is that the Sensor Analysis crashes towards the last steps when it starts changing the Binning settings. I repro'd the bug and filed the 2x reports already.
## Conclusion
I'm soooo happy to find that the latest DirectShow driver will let me efficiently shoot short subs for Live Stacking!!! It feels almost as good as native SDK driver support. My only gripes with it are that the 'old' DirectShow driver seems to still appear as an option in the Camera menu with the exact same name as new new good one. I tried it and it only had RGB32 which immediately looked wrong with my mono sensor. I'm not worried about Binning except to complete a valid Sensor Analysis with this driver. I can't tell for sure if it is indeed USB 3.0 or not, but the framerate is fast enough for "Lucky DSO" and I have a different planetary camera for the real fast stuff anyway.
Cheers and clear skies!
-John Leimgruber "ubergarm"
## Screenshot Attachments
* DirectShow OGMA "AP26MC" driver working great maxing out published FPS on low noise mode.
* DirectShow "ASCOM" driver set to 10s subs showing slower than expected FPS.
* SharpCap Camera Menu showing two identically named DirectShow drivers and which one is "good".