I certainly can’t make any comments about ASCOM cameras in general, as I only own a QSI683 and a LodeStar X2 but I have time stamps bracketing the
int[,] PixelArray = ( int[,] )myCamera.ImageArray;
command and it takes 7 seconds to execute when the QSI683 is 2x2 binned. If the pixel data was already in the driver, this command would take milli seconds; not the 7 seconds I am seeing. Seven seconds is just about exactly the same amount of download time I see reported by SGP.
In fact, I have timers around the “StartExposure()” and the “ImageArray” commands. When I make a 300 second exposure, I see exactly 300 seconds reported for the exposure command followed by the 7 seconds of the download command. I don’t know what I would see using other cameras, of course.
The initial question was whether or not there is time between the end of an exposure and the start of the download to issue a dither command to run in parallel with the download. It looks like that answer will vary depending on the model of camera as it would depend on when the “ImageReady” flag becomes true; that is, does the ASCOM driver set it to true before the pixel download from the camera or after?