Quote:
Originally Posted by bmitchell82
The grainyness is possibly due to two things.
1. 300 seconds although it isn't a short exposure it isn't really that long. the longer the subs the better the SNR the less grain.
2. Slip into photoshop--->Channels and click on the individual colours you know you have tapped into that colour when your image turns grey.
I had this issue due to the fact i only had 2 ea @ 10min of RGB with my HH i posted on sunday. The reason being there was very little blue and Green in the dark dusty areas so it produces alot of noise. If your crafty you can do some selective blurring to tame the noise to a tolorable limit.
The other thing i notice with your images is that while they are in focus they are blurry this shouldn't really be and your collimation isn't out by that much. I don't know if Grahames ronchi eye piece will work (I suspect it will) to assess the mirrors i think something isn't quite right.
|
1. Thanks for the tip. I have been keeping the exposure down to avoid light pollution but in that particular direction i could have gone for longer subs. My guiding was great so I should have tried to push it for 8-10 minutes at least.
2. The most grainyness was noticable in the blue part of the RGB. I have used selective colour and i could have deblurred a bit more .
3. I've been saying this myself and I have sent some test images to Michael at Bintel for comment.
Many Thanks.
