Change exposure slider - Count down timer goes negative

[sink45ny]

Why if I Change exposure slider the count down timer goes negative and seems to go on forever negative.

I assume I am doing something wrong, please enlighten me.

Thanks
Steve

[admin]

Hi Steve,

what make and model of camera are you using?

The negative countdown means that the expected frame is overdue. For most cameras SharpCap will restart the frame when you change the exposure, and also give up and restart if the frame is delayed by too long. Sometimes there have been issues with this or improvements added, so make sure you have the very latest SharpCap 4.0 or 4.1 beta and check again. If it still is not right, let me know along with details of the camera and I will have a look to see what might be going wrong.

thanks,

Robin

[dridge3770]

I'm having the same problem. I'm using 4.1 (64bit). Qhy183C and Lodestar cameras are both doing that. Very frustrating!

[admin]

Hi,

Ok, thanks for the info. The negative count usually indicates that an expected frame from the camera is 'overdue', which can happen due to a variety of causes, but one thing that is definitely worth checking is the USB connection...

If you are using any long cables/hubs/extensions, remove them and connect the camera direct to the PC using a good quality cable (less than 2 metres in length). If that helps fix things then you have identified the cause of the issues and can experiment with different options for longer cables, testing each time to see if you still have a working system.

Additionally, the QHY camera has a 'USB Traffic' control and a 'Force still mode' control. Try setting the USB traffic to a higher value for more stability of the camera (lower maximum frame rate though). Also try the 'force still mode' set to on, which may help.

Hope this helps,

Robin

[dridge3770]

Hmmmm.... I just implemented a USB hub to accommodate an additional device (SX-AO). It was surprisingly inexpensive (or should I say "cheap"?). Have you had any experience with specific brands or with certain hub specifications that might avoid this problem?

Thanks, Robin.

[admin]

Hi,

cheap USB hubs are a bit of a lottery when it comes to component quality and reliability. They will likely all work well for low speed devices that just send a bit of data (filter wheels, focusers, etc), but cameras can be an issue. If testing without a hub shows that the cameras work then the best option would be to run a direct cable back to the PC for the camera and use the hub for all the low speed stuff.

Personally, I'm now using a Pegasus power box as both USB hub and 12V distribution, but they are not cheap...

cheers,

Robin