Shooting Perseids with G11

Ok, I am hoping to capture some shooting stars next week. My gear is the G11. This is what I am planning on

20-30 second Tv (using CHDK)
200 or 400 ISO
4.0 Av
Manual
One click back from infinity on MF
IS off
continuous AF off
in RAW
on Tripod
Using CHDK for minimalistic script to simply take pic after pic


Is this a good setup? I seem to be having issues with RAW at 200 or 400 ISO, 4.0 Av, 26Tv on a tripod and there is a lot of noise when adjusting the raw image...I must be doing something wrong.

EXIF will show this at 15s, but when using CHDK, it always shows EXIF maxing out at only 15s as it is the camera's limit.

Can't comment on your chances, but when I looked at my G11 in manual mode and backing off the focus from infinity one click, it seems that it's about half way back to 10'

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Interesting you mention that. I too get that, but then on some occassions, when I back up 1 click from infinity, it is a tiny movement (more ideal than what you show). However, I am unable to determine why and in what situations causes it to be different.