The 40D has three "C" modes. What I would recommend is pre-prepping them so that in the field you can set up a shot to capture quickly with just the flip of the dial.


Like have the first one C1 setup with the camera settings so that it begins with a negative exposure compensation and C2 with a positive exposure compensation so that you can put the camera in AEB mode and fire off three AEB in C1 and then turn the dial to C2 and immediate fire off three more.


I'd imagine if you used C3 as well you could use all three settings to work out 9 exposures, but at the expense of having to touch the camera twice (once each time you turn the dial). A very steady (rock solid) tripod is crucial if you intend to touch the camera. You'd be amazed at how easy it is to change the alignment touching the camera even lightly.


If you do the math based on the steps between each frame of your AEB, then you can very quickly end up with 6 frames equally spaced using C1 and C2 (9 if you also use C3). The only challenge you will have in post is that they were taken separately so the software may ask you to input the steps you used manually after you have selected the images to use when merging to HDR.


Michael James


http://www.digitalcoastimage.com