Still Have Grain
 

I've been doing everything right....

NO gain. NO AGC (of course).

But when I upload my Canon XH-A1 footage into Final Cut, I still have jumping grain over parts of the image.

Could it have something to do with the shutter -- which I keep at 1/24. Or maybe a preset?

I noticed the same problem. Even at 0db, there are still noise. Now I have to set the camera at -3db as suggested by other members.

Yes your shutter speed could have something to do with it. Why 1/24?
Also what frame rate?
How much light?
What aperture?

Not enough information, sorry.

For example, AGC is always on (even though the switch is set to off) when the program mode is in the Green Box position.

Right. I don't use the green box position.

Frame rate is 24. I like the look of 1/24 on motion. I vary the iris depending the situation.

When I set my Low gain to the -3db setting it helped greatly and I'm now happy.

You've got to remember though that any camera that has three 1/4 inch CCD's will struggle with grain to some degree, especially in low light, so make sure your scenes are lit as good as possible. Darker scenes can be delt with in post much of the time.

Until we can all afford cameras with three 1/2 inch CCD's we'll just have to learn the tricks to combating grain. Try lowering your low gain to -3.

The XH-A1 has 1/3" CCDs not 1/4".

Try manual mode, gain -3db, 24fps, 1/48 shutter speed. Set your zebras to 100 ire,
now open the iris until you see the proper exposure.

Yes, that's what I meant of course 3 1/3 CCD's.

Not being funny but what are you viewing the footage on?
You shouldn't be getting grain in manual mode with Gain at -3 and usual shutter speeds.
Was the location dark?

Can you post a full res screen image?

Edit: Also is the grain across the picture or just for example in the blacks?