Here is a link to two RAW subs - now we are thinking about "can we see the effect in the images"
This was something David suggested I do to see the effect
You can see in the 90 second sub, the FWHM is lower and the eccentricity higher compared to the 900 second sub
Obviously the 900 is getting more exposure to dim light, but the question David proposed to me was, is the 900 sec sub just smearing the error around a bit, bloating stars and making them appear more round and less eccentric (I measured a bunch of subs and the pattern held for all subs)
Or is the 900 sec sub just bringing in more light, so getting a better image that is more "correct" ?
I don't really know how to answer that.
Some of it may be the duo-band filter, which aren't known for being super high quality filters. I may bite the bullet and remove it and tweak the spacing and see if I get different results.
Part of it is I am not sure what expectations are reasonable and what aren't
