High Dynamic Range Photography

This week I've been mostly experimenting with HDR photography using my Canon PowerShot SD950 IS and CHDK. CHDK is a hack for certain Canon cameras that allows you to do things like shooting in RAW mode, and automatic bracketing. I haven't really got the RAW-mode working well yet (but I'm not sure that's a great loss - as the compact cameras don't really have the bit-depth that makes RAW really worthwhile on a DSLR), but the bracketing has been useful. CHDK also has scripts for motion detection, and time-lapse, which may be the trigger for a future project.

Using the bracketing you can set CHDK to take a series at +/- 1EV, and then go into the native custom timer - set that for 3 or 5 shots, then push the shutter - and the camera does the rest.

After taking the shots - I then used Dynamic Photo HDR to integrate 3 low-dynamic range photos into one HDR shot, which you then tone-map back into 8-bit space for viewing. It probably isn't the most advanced s/w for the task, but it's nice and easy to use. There's a great list of s/w at HDR Labs.

I also did one experiment to see how to run HDR and AutoPano together. It looks like you can do HDR & tone-map first then pano the results, or pano first then HDR and tone-map the panos; although with AutoPano's ability to run multiple bracketed shots together into a set of panoramas - I think pano followed by HDR is the simplest option. (I did get a slightly better result doing the HDR first, but I think this was likely due more to my processing than anything fundamental.)