I too was looking for a script for the 2017 solar eclipse - and I've found it! Waterwings has made a script "HDR lapse" that fulfills the requirements just perfectly. (
https://chdk.setepontos.com/index.php?topic=11036.msg107966#msg107966). <Thanks Waterwings!!>
I am using a PS SX130is and version 1.41-4883 of the CHDK. I am using the camera in "M" mode and then in CHDK enhanced settings, am using: override Tv at 1/200, override Ta at 8.0, override Iso = 80; override sub dist <inf>. Then loading the HDL lapse script, for the pre-totality portion, I am setting number of steps to <3>, 1/2 f-stops per step to <2>, shots = 0; interval = 2 minutes, shot mode to fast, and enabling RAW and DNG. What I get is 3 shots every 2 minutes: one at 1/100, one at 1/200, and one at 1/400 sec. For the totality part of the eclipse, I'll use different settings to fully bracket the event: number of steps = 5; 1/2 f-stops per step to <3>, shots = 0; and interval = 10 seconds. What this gives me is continuous shooting starting at 1/25, 1/60, 1/200, 1/640, 1/1600 seconds and then repeating. I am finding that with my camera, this series takes about 20 seconds before repeating. I am able to get about 200-240 shots using my pre-totality setting and am now experimenting with turning off the lcd during shooting. I am setting the camera powersaving menu to turn off the lcd after 30 seconds and in the CHDK settings menu have set "disable lcd off" to <never>. So after 30 seconds the lcd turns off. After I have started the script, I need to re-aim the camera so need the lcd 'on' to do this. I exit <alt> mode (on my camera the 'face' button) and then hit the 'display' button, and then return to <alt> mode again using the 'face' button. I re-aim and the script continues running. I should be able to increase the number of pics I can take without changing the batteries! Hope this helps! Clear Skies to us ALL! (be sure to check out suncalc.org to get altitude and azimuth settings for your location to help you aim your camera)
