Binning?

[Daz1969]

Hi all, Can any one tell me what binning is ? and when and why would i do it? Also,is a binned pic the same size as an un binned pic in that could you combine binned and non binned?

Am i making any sence:icon_scratch:

Daz

[Merlin66]

Binning is when you combine say 2 x 2 pixels into a "super 4 pixel" pixel.

It's more sensitive and is obviously larger. The well depth ( ie the amount of photons it can accept) is the same as the initial pixel ie 16bit etc.

Yes, they can be combined with normal pixels.

Why and when?

To get larger pixel sizes to better match the resolution of the optical system. To get a larger pixel with good sensitivity.

Ken

[Daz1969]

Ok,Beginning to get it..Mmm What do you mean exactly about matching the resolution of the optical system.?

[Merlin66]

It's all about getting good sampling without over or under sampling.

The Nyquist sampling says that you need the smallest image to cover at least 2 pixels to get full resolution. If your seeing is average then you may only have images 3 or 4 sec arc; this would need to cover 2 pixel which is 20micron image. It depends on the focal length/ plate scale whether th is matches to scope or not.

Change the effective pixel size to 15 micron and you are undersampling at the same focal length.

Like wise if the image size is larger, you can still get good sampling with a larger pixel..

Ken

[Daz1969]

Ah ,Thanks Ken, I am grasping it now:)

Cheers

Daz.