Replying to myself: Thanks to Acid and SDMInst I got my
S100 booting CHDK. It took some fiddling to get that TTL script installed and learn my way around the OS, but... with the linked script, TTL flash in manual
does seem to work. I tried some test exposures with my housing and scuba strobe and exposures looked pretty good at a variety of manual exposure settings.
Things of note for anyone else who wants to try this--
- The S100's own 3-step flash power setting is still active when TTL is forced on via the script. I found that exposures looked best with this setting at its lowest value. YMMV.
- The script has its own power override too, in the script config menu. and I do not know how the two values might interact--didn't play with that. I left it at its default value.
- If your strobe has a TTL-friendly power dial, it too factors in to the exposure. It seemed to me that the adjustable power on my S&S DS-01 did not produce as wide a range of adjustment as I see in an unmodified Canon aperture priority mode with TTL.
I think this would be a nice feature to add to CHDK's own configs, but the script definitely does the job. Thanks for the help Waterwingz, without your assistance I probably would have just believed those old forum posts and never tried this out.
