Region of Interest

[Demonperformer]

Apart from the smaller sizes of files, are there any advantages to using the ROI settings when imaging a smaller target compared to cropping the end result?

[JamesF]

14 minutes ago, Demonperformer said:

Apart from the smaller sizes of files, are there any advantages to using the ROI settings when imaging a smaller target compared to cropping the end result?

For long exposures, perhaps not.  If you're using short exposures and high frame rates however, setting the ROI smaller potentially allows a higher frame rate, or reduces the number of dropped frames by avoiding saturating the connection between the camera and computer.

James

[Stargazer33]

I was really surprised at how much my frame rate increased when I selected a smaller ROI.

[Demonperformer]

Ah, yes, solar system imaging I can see would benefit from it. I was mainly thinking of smallish DSOs. A 10' galaxy on my main setup would occupy about 300 px and I was wondering what I might gain against using the full 5000x3000 chip, compared to having to redo different flats for the bit of the chip I would use with ROI. 

[JamesF]

Processing smaller frames will probably be faster, too.  My personal taste is not to crop too much though.  I think it's nice to see small DSOs in context.

James

[Demonperformer]

Yes, that would make a lot of sense. Personally I won't find that too much of an issue as I am using Sharpcap's live stacking procedure, so as each frame comes in it gets processed and added to the stack before the next one arrives anyway.