SharpCap Forums

SharpCap version:
4.1.13218, 64-bit

Camera:
Touptek 678C in combination with the default driver provided by SharpCap

Operating System Version:
Windows 10 64-bit

Problem Description:
The framerate reported by SharpCap is higher than it is supposed to be.

Examples:

• 08ms -> 180 FPS
• 16ms -> 91.5 FPS
• 32ms -> 45.8 FPS

Additional Information:

• Changing the raw mode (8 bit / 16 bit) or changing the read mode (normal or HDR) or binning does not solve the issue
• The issue persists after a reboot
• The issue persists after uninstall/reinstalling SharpCap
• Other cameras (ASI678MM) reports the framerate just fine

Hi,

are these frame rates happening at full resolution on the camera, or when you are using ROI. In either case they are odd, since the values exceed those compatible with the exposure times (ie maximum 125fps at 8ms). If it is at full resolution then it is *doubly* odd as the data transfer rate to the PC should exclude those rates from happening. Unfortunately the log doesn't really record anything very helpful in this sort of situation.

Assuming that the frame rates you are seeing are happening with the camera at a small ROI then the logical conclusion would be that the camera is actually using an exposure a bit below (~30%) the specified value. That actually seems likely, since the percentage change from the expected frame rate is about the same in each case.

cheers,

Robin

Hi Robin, I'm using a ROI - noticed the issue when I was capturing a recording of Jupiter last night.

I think the issue can be closed though, I was wondering if Firecapture had the same issue and apparently it does so this is something caused by the Touptek dll/driver and not by SharpCap. If you have some contacts at Touptek then please don't hesitate to get in touch with them to discuss. Otherwise, I'll drop them an email explaining the issue. Thanks for your feedback.

Hi,

I'll pass this on to ToupTek - from all accounts it sounds like the calculation that converts exposure time into the camera commands needed isn't quite right for this model in the SDK.

cheers,

Robin

Hi,

actually it looks like there is a newer SDK version on the ToupTek download site than the once currently in SharpCap - I will try updating to that in the next SharpCap update to see if that helps.

cheers,

Robin