Binning quick question

[Stryda]

Hi just a really quick question! how exactly do you bin an image? ie 2x2, 3x3 etc. Is it done by a setting on the camera...which if it is i cant seem to find (canon 50d) or is it done via some programme in post processing? Id reallyyyy appreciate an answer asap if possible by anyone as im about to go out and start some shooting, so would like to give it a go tonight. Thx

[SteveL]

you normally cant hardware bin a DSLR, its usually only dedicated Astro CCDs that allow hardware binning

[Stryda]

ohh thats probs why I couldnt find the option

[Shibby]

Was just about to start another thread but found this...

So... binning, am I right in thinking the same is achieved by resizing an image, e.g. to 50%? If so, is there any particular resize algorithm that should be used?

[SteveL]

No, binning is not the same as resziing to 50%. binning at 2x2 means that a 4 pixel area (2x2) is collecting the photons but reporting back as one pixel in size. The image size will be 50% of the original, but the amount of data collected per pixel will be 4 times what it would be without binning.

[Shibby]

Ah ok, but is there not some way of reproducing this after the fact? By combining 4 pixels into one?

[SteveL]

You can use software that will do software binning (i.e add the values of the 4 pixel together), but that isnt the same as resizing (i.e average the value of the 4 pixels into 1 value).

[RichieJarvis]

Nebulousity does support binning on the Canon DSLR's - its not free, but is reasonably priced.