ZWO ASI385 Highspeed Frame Drops
Posted: Wed Dec 05, 2018 6:04 pm
Hi Guys,
I'm having an issue trying to use my ASI385 camera in highspeed mode in the most recent Sharpcap 3.2.
The camera works fine in the RAW16 color space with frame speeds up to 65 fps using the full sensor ROI... essentially no dropped frames.
When I switch to the RAW8 color space (which is required for highspeed mode), the camera starts acting a little unstable.
As long as I keep the ROI at something less than the full sensor (for example 1920 x 1080 which is just slightly less than the 1936 x 1096 full sensor), it seems to run fine at regular speeds, but when I switch to highspeed mode, it starts dropping a lot of frames, which of course drops the frame rate way below even 65 fps. I've tried changing the memmory settings, turbo USB settings, etc..., but with no luck fixing the problem.
I've narrowed it down to a SharpCap issue by trying the same set-up in ASICAP (ZWO's capture software). Using the same cables and same USB port on the same computer (Windows 10), the issue does not occur. In ASICAP with the highspeed mode on (RAW8), I can get frame rates upto 120 fps with the slightly reduced ROI. Please note that if I use the full sensor, even in ASICAP, it acts a little unstable with some dropped frames. However reducing the ROI to the next smaller level, I get essentially no dropped frames in ASICAP at 120 fps and even up to 200 fps with smaller ROIs.
I have noticed that the SC status bar at the bottom reports "3 of 1018 frames in use" when it is not dropping frames and it changes to "2 of 1018 frames in use" when it is dropping frames. However, I don't know if that's a possible cause or just a symptom. Also, I can achieve the 120 fps+ in SharpCap when I reduce the ROI to something very small (like 256 x 256 pixels). I've also noticed that if I keep the camera in this mode and try various ROI's the camera becomes more and more unstable and eventually stops responding, even when I switch back to RAW16. At that point I have to close and restart SharpCap to get the camera going again.
I've attached a screen shot from SharpCap that shows the camera settings. With these settings, the camera will flip back and forth between periods of dropped frames and periods of no dropped frames. This screenshot was early on so it is only around 10% dropped frames, but will climb to well over 50%. I've also attached the SharpCap Log I recorded shortly after it started dropping frames in this mode.
I noticed while I was previewing the attached screen shot that it is reporting the camera temperatuer at 76C! Which I do not believe is accurate for several reasons. When I opened the camera in ASICAP right afterwards, the temperature was reported at 32.7C and when I switch to RAW16 mode in SC it behaves normally... I'm not sure if this is a related issued.
Thanks!
Bill
I'm having an issue trying to use my ASI385 camera in highspeed mode in the most recent Sharpcap 3.2.
The camera works fine in the RAW16 color space with frame speeds up to 65 fps using the full sensor ROI... essentially no dropped frames.
When I switch to the RAW8 color space (which is required for highspeed mode), the camera starts acting a little unstable.
As long as I keep the ROI at something less than the full sensor (for example 1920 x 1080 which is just slightly less than the 1936 x 1096 full sensor), it seems to run fine at regular speeds, but when I switch to highspeed mode, it starts dropping a lot of frames, which of course drops the frame rate way below even 65 fps. I've tried changing the memmory settings, turbo USB settings, etc..., but with no luck fixing the problem.
I've narrowed it down to a SharpCap issue by trying the same set-up in ASICAP (ZWO's capture software). Using the same cables and same USB port on the same computer (Windows 10), the issue does not occur. In ASICAP with the highspeed mode on (RAW8), I can get frame rates upto 120 fps with the slightly reduced ROI. Please note that if I use the full sensor, even in ASICAP, it acts a little unstable with some dropped frames. However reducing the ROI to the next smaller level, I get essentially no dropped frames in ASICAP at 120 fps and even up to 200 fps with smaller ROIs.
I have noticed that the SC status bar at the bottom reports "3 of 1018 frames in use" when it is not dropping frames and it changes to "2 of 1018 frames in use" when it is dropping frames. However, I don't know if that's a possible cause or just a symptom. Also, I can achieve the 120 fps+ in SharpCap when I reduce the ROI to something very small (like 256 x 256 pixels). I've also noticed that if I keep the camera in this mode and try various ROI's the camera becomes more and more unstable and eventually stops responding, even when I switch back to RAW16. At that point I have to close and restart SharpCap to get the camera going again.
I've attached a screen shot from SharpCap that shows the camera settings. With these settings, the camera will flip back and forth between periods of dropped frames and periods of no dropped frames. This screenshot was early on so it is only around 10% dropped frames, but will climb to well over 50%. I've also attached the SharpCap Log I recorded shortly after it started dropping frames in this mode.
I noticed while I was previewing the attached screen shot that it is reporting the camera temperatuer at 76C! Which I do not believe is accurate for several reasons. When I opened the camera in ASICAP right afterwards, the temperature was reported at 32.7C and when I switch to RAW16 mode in SC it behaves normally... I'm not sure if this is a related issued.
Thanks!
Bill