M16 & M20 with cool mod ASI120MM-S

Sam@ZWO

6"f4 + ha filter

M20 gain 40 16bit 90S*100

M16 gain 40 16bit 60S*100

chripell

Very nice! Just 2 notes:

1) it looks like there are some vertical bands on the Trifid. Is the nasty "vertical noise reduction non kicking-in" problem striking back? :-(

2) it seems that you have some coma. Look at the starts in the upper left and right corner of the Trifida (or rotate left by about 90° in M16). I'm plagued with a similar problem, if you align the newton with a Cheshire, it's not sure that the sensor of the ASICam will be centered too. So, for the next YAACA release, I'm planning a function to measure the "roundness" of a star. Then I'm planning to use this plus an artificial star to do the alignment directly wit the ASICam mounted: this should more reliable.

What Delta T you get with your mod?

BTW I'm attaching my best M20, unfortunately it's very low where I observe (and versus south I have 2 big cities with a lot of IL :-( ): M20, CLS filter , 30 x 60" of lights e darks, ASI120MC cooled, 6" f/4 GSO

Sam@ZWO

Hi Chris

your picture is very nice!

1. the vertical band problem is a guider and stacking problem.

because the images move little between each and a dark-subtract is not matched very well.

so the noise is there after DDP, you can tell its there in the M16 too, in another direction.

2. the coma is more heavy than I think, maybe a align problem, I will do more test

the Delta T is -30 degree now, I think it can be more