To Bin or not to Bin

[icpass]

Hi

After getting all the Ha subs I am now getting the o3 I was told to bin it 2x2 ,but im not really sure what it does.

The 1st sub came in and was pixallated ,what effect does this have on final image or am i just after the dso data.

Ian

[SteveL]

binning at 2x2 make a 2x2pixel area return data as if it was one large pixel. It gives you 4 times the light capturing ability (making it more sensitive), but reduces the size of the returned image to a quarter of the original (half width, half height).

Same goes for 3x bin, except its 3x3...

[icpass]

Steve

Thanks for that,when i stack the binned images how well will they combine with my unbinned ha data.

Ian

[Tim]

Not to.

There is a growing wave of opinion that unbinned colour captures give a better overall result.

Certainly for O3 there is a lot of tiny detail and structure that will be degraded by binning, as you see.

TJ

[SteveL]

As TJ points out, binning is a tradeoff between image resolution and decreased image capture time.

[roundycat]

there is no question that binning will badly affect your subs if the seeing will support something around twice your image scale. If your image scale is 1"/pix or less binning will be worth while. It will half (at least) your linear resolution of fine detail and can give you blocky stars. Always try unbinned first unless your skies are really bad.

Dennis