Should I Bin my RGB?

[gnomus]

At present I am using a Skywatcher ED80 with a focal reducer and an Atik 383L,

When I plug all of this into FLO's Astronomy Tools calculator, this tells me that my imaging resolution is 2.18" x 2.18".  Am I correct in thinking that if I choose to Bin 2x2 my R, G & B data, then that will be captured at 4.36" x 4.36"?

Is it advisable for me to Bin my R, G and B at this level of resolution, or should i capture these data unbinned (as I do with my Lum), even if that means that I will have to capture more (in terms of total exposure time) R, G & B ?

Thanks in anticipation. 

[ollypenrice]

A lot depends on the target. Most, if not all, my galaxy images have starfields made up of RGB-only. I can get smaller and more colourful stars by dropping the luminance from the starfield. The L just makes stars bigger and more core-saturated. If I were to bin my colour this trick wouldn't work because I'd probably have big, blocky, core-saturated RGB stars.

Similarly very dense starfields such as found in the Milky Way would suffer slightly if binned on your setup. Probably not a lot, but a little.

So there's no free lunch. You save a little time by binning colour and on some setups and some targets the price paid can be negligible.

After I'd been imaging for a few years I stopped taking much notice of the various orthodoxies that have taken root on the net. '30 minute luminance subs will saturate large areas of most images.' They don't. 'You often need short subs to handle bright parts of a target.' You don't. Etc etc. So if I were you I'd do the only thing that will answer your question accurately and that's experiment.

Olly

[gnomus]

Thanks for spelling out what the issues are. I will experiment, as you suggest. I have taken only one image so far. The thing that struck me was the extra effort required in capturing 2x2 flats, darks and biases. (I know I may not have to do the darks and biases again for a while, so long as I capture at the same temperature). This meant that there was also a little more time that had to be spent in processing all of these data.

I will try unbinned next time I think.