Quote:
Originally Posted by gregbradley
You bring up some interesting points Stuart.
With regards to 1x1 binning for colour Martin Pugh and Don Goldman and I think R Jay Gabany all said to do colour in 1x1.
I have started doing this on a few images having almost always used 2x2 binning on rgb before (I have done 1x1 on a few occassions).
I think the answer is it depends on what you are shooting and your setup. All these guys are shooting with 3 metre focal length scopes so its a different scenario. With my CDK17 I noticed 1x1 RGB were cleaner, more detailed, less vignetted and cleaned up with callibration better than 2x2 would. So with that setup I think there is a definite improvement over 2x2. As far as how much longer it takes, it does not seem to be 2 or 4 times longer at all. If the data is clean and callibrates better it leads to a nicer image. Martin did recommend longer rgb times than what is typically seen on this site.
Also other factors come into it. Doing a 20 -30 hour masterpiece of every object you intend to image may not be everyone's thing.
Or if you travel to a dark site it most certainly is not a practical approach. Its for those with a home or remote observatory where you can buildup the hours.
But your idea of putting more into the luminance has some merit.
I think 1x1 binned colour makes sense for galaxies or dim objects with fine detail or any object really at long focal length.
But for a widefield perhaps not so much especially at a travelled to dark site where imaging time is precious.
Greg.
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Hi Greg,
I think it makes even less sense to not bin images at long focal lengths, oversampling will not positively affect the result. Unless there are very sharp colour changes in your images (other than black to colour around stars), how would seriously oversampling your RGB help the image quality?
Just because some legends do it, doesn't make it right, it just means that you have to argue long and hard to make people change their mind. We also don't know their pixel scale, some of these guys work with exotic cameras that may have huge pixels to match their focal length.
I'd defer to Craig Stark on this one if his opinion differs, he backs his argument up with mathematics.
If, however, you feel better doing it, go right ahead, they are your photos. I have done some tests binning and not binning my RGB, couldn't tell the difference except the not binned images were noisier for the same exposure time, hence I bin my RGB.
Cheers
Stuart