I am new to CHDK and this forum. I've found this to be absolutely fascinating and am trying to learn what I can.
I have a particular use that I am having trouble understanding. I recently flew a high altitude balloon to 61,000' and had onboard a Canon A570is runing an intervalometer program taking a photo every 30 seconds. It worked very nicely. However, the balloon did, of course, get above the cloud deck and in to the bright sunlight for a good portion of the flight. As such the camera over-exposed the cloud deck quite badly. I believe the Canon attempts to average the field of view for a good exposure but in a HAB flight there is far too much contrast from the upper edge of the dark of space to the blue atmosphere to the extreme white of the clouds. What I need, I believe, is a bracketed intervalometer to drop an F-stop or two when above the cloud deck but still maintain the average when below. The HAB flights typically take about 2.5 hours up and down and taking a photo every 30 seconds seems to get those terrific 'money shots' at altitude. Can anyone help me find a script and understand a bit more on a good place to start with settings?
These are photos from 61,000' on my recent flight:
Thanks!
Pete
