SharpCap Forums

I'm not sure if this is a problem with the software or the camera.

I have a Lodestar X2 Mono and any exposure time I choose over 1 sec takes twice as long to show an image. So for example if I pick 2 seconds the countdown will go to 4 seconds before the image shows up. If I pick 4 seconds the countdown goes to 8 seconds before an image. 8 seconds goes to 16, 15 to 30, etc.

This happens no matter what color space and resolution I choose. At first I thought it was the hub or extension cable but I get the same behavior when plugged in directly.

I also have a QHY5L-II Mono and it takes double time on the first exposure but then is normal after that. I am running SharpCap 3.1 beta under Parallels on a 2016 MacBook Pro.

Is this simply a limitation of USB2 cameras, a problem with virtualization or is there something else going on?

Hi,

this is a peculiarity of the Lodestar camera which is an interlaced camera - that means that you can only expose 1/2 of the pixels at one time (as far as I can work out anyway). So, if you want a 4 second exposure at full resolution you have to do a 4 second exposure for rows 1,3,5,7 etc and then another for rows 2,4,6,8 etc.

There is a control to let you tweak this - 'Interlace Handling' - you can choose various options, some of which give the double time you are describing and some that do not (but those that do not are effectively throwing away half the vertical resolution).

cheers,

Robin

That makes sense. Thanks for the explanation.

Maybe there should be some way of conveying this information to the user though as this can be very confusing. At least a mention in the manual (although who reads those ).