Process images before or after stacking?

[jnp]

I am quite now to this and am using CANON's Digital Photo Professional to process my unmodded 1000D images of DSOs. This is pretty much a matter of tweaking the tone curve adjustment to essentially boost contrast and cut out light pollution. I normally stack first and them process, but I discovered that you can apply the saved tone settings (as a 'recipe') to multiple images at once and then stack them.

I was hoping that the additional 'noise' introduced by processing might be cancelled out if they were processed before stacking. I have tried both approaches and unfortunately, can't see decide whats best (because each approach needs different tone adjustments).

I assume most people here would just stack before processing?

thanks

John

[SteveL]

stack then process... always...

[melsky]

I too have been experimenting with pre/post stacking processing and using Photoshop’s raw converter there is definitely an advantage to applying curves to the raw files prior to conversion and stacking, I have no experience with the Canon program however I am using both Canon 5D and 500D unmodded camera's.

Mel