2 replies to this topic

[dcaponeii]

I took three captures of Venus last night and all suffer from an acute case of banding parallel to the terminator across half the face of the disk.  It really comes out if I try and sharpening of the images.  Not sure what is the cause.  If you've seen it before I'll appreciate know the source and of course how to prevent it from occurring.  It looks like an old JPEG artifact from back in the day.  I tried de-rotating three images hoping it might average out but no suck luck.  Here they are just because I did the work and so you should have to deal with them, just because.

 

First the single image.  GAIN = 0, 2.5ms exposure.  (OH WAIT!  Do I remember that low gain levels will produce this kind of banding in planetary cameras???)  Problem is that at "more normal" GAIN levels the exposure becomes so short I start having camera connectivity issues.

 

 

 

The de-rotation.

 

[KiwiRay]

This is a colour image, right? With just the IR cut filter, I image with the ASI224MC at a gain of 180 and exposure of 1ms, although the ROI means I'm only capturing about 500 frames/s. (Yes, I could drop the gain and increase to 2ms, but it doesn't really matter when I'm capturing >100K frames). If your computer struggles with that, perhaps use a filter of some kind to reduce the amount of light, while also increasing your chance of capturing some detail.

[dcaponeii]

This is a colour image, right? With just the IR cut filter, I image with the ASI224MC at a gain of 180 and exposure of 1ms, although the ROI means I'm only capturing about 500 frames/s. (Yes, I could drop the gain and increase to 2ms, but it doesn't really matter when I'm capturing >100K frames). If your computer struggles with that, perhaps use a filter of some kind to reduce the amount of light, while also increasing your chance of capturing some detail.

Yeah maybe one of the lunar filters I've got floating around would do the trick.  16" light bucket was just too much for the camera I guess.