I shoot on an XH-A1 and, until recently, have been editing with an older non-HD Apple Cinema Display. The other day I purchased an Apple Cinema HD Display, and am now dismayed to see quite a bit of grain in much of the darker footage that I shot: this was not nearly as evident on the older display.
The footage was shot on 1080 60i, with 0 db Gain, on a street corner at night, utilizing the street and shop lights. Should I be shooting on -3 db Gain? Why is gain appearing, even though I have it set at 0? I must also note that auto gain was off, so this was not a factor in the final image.
If you're shooting in low light, you are gonna get grain no matter what the gain setting is. Its a function of the semsitivity of the CCDs. There are some settings in the XH A1 that may make the grain less visible, and some things to do on the computer later to help minimize the grain. Serach this and the final cut pro forum for "grain" and also for "low light presets XHA1". The XH A1 is not a great performer in low light, its good but not great.