Gain - In camera or in post? Which is best?

[Kevin King]

Sometimes I'm stuck in very low light and don't have the option of adding light. I shoot w/ a XL1s and a GL2.

Normally I keep in-camera gain at 0 or as low as humanly possible. In these real dark situations, I can get near proper exposure by bumping gain up to 18 or so, but an obviously noisey picture.

Would it be better to leave the in-camera gain low, intentionally under-expose the image, then use a levels adjustment in post to artificially re-brighten these images?

I know it's the lesser of 2 evils, and no solution is really the "right one", but can someone share some technical details about the levels software process vs. the cameras CCD boost for "fake light"?

If a post solution is best, can someone point me to a tutorial or further info about using levels controls / brightness contrast controls and so on - to get the best result w/out loosing too much? (I just tweak w/ these settings until the image looks 'better' - I don't really know how to properly use them).

Thanks!
-Kevin

[Ken Tanaka]

There's no one-size-fits-all answer here, Kevin.

On the one hand, if the darks are completely crushed in the image, their embedded details are lost forever. If boosting gain is the only way you can extract that detail, and if that detail is important, then gain is the only practical recourse available.

On the other hand, gain grain is nearly impossible to remove. You'll have to be at peace with it.

Recovering crushed (underexposed) dark areas is not possible in post (just as recovering blown brights is also not possible). The information is gone. So you have to decide what's most important for your shoot.