Region of Interest question

cwiecha

Hi all -- I'm a new user of an ASI120MC-S and gradually learning the ropes around capturing images and stacking etc. It has become clear just from the first night out that excellent collimation and focus are required to get any type of detail on Jupiter, the only target I have tried so far.

I will recheck my general collimation and focus more on focusing :-)

...but have a question about how ROI works and how this might be causing some problems as well.

Am I correct that the ROI subset of the chip is taken from the top left of the field of view? It seems that I have to move my object off center to position it in the FOI field of view, rather than subsetting the frame from the center of the chip.

My concern is the corners of my FOV the focus and collimation are likely to be poor relative to the on-axis performance, even with good alignment.

What do you all do for this? Refocus for the corner? Tweak collimation to optimize for there as well? This seems kind of weird to have to do...

I can image at full frame to keep the object centered on-axis but really like the high frame rates I can get with USB with a smaller ROI.

Any advice/suggestions/corrections more than welcome!

Thanks, Charlie Wiecha

james_screech

I assume your using FireCapture, it has an option to centre the ROI to the centre of the chip. Also as the chip is relatively small collimation / focus should not be a problem in different parts anyway (unless your camera has a chip placed badly).

James

cwiecha

Super...I missed that the ROI is actually centered! That's great.

Thanks! Charlie