I like the way it looks until it gets to a night sky and then the images start to over expose and the whole image is brighter. Would the settings for "ignore the sun" for a sunrise work for a sunset so the image goes darker at night? Or do I have to play around with the over exposure settings when going from light to dark?
If I've understood this, the Bv/Ev shift settings I described are what you want for this. For as sunset, you can set the "base" value to "first", so the first shot will be normal exposure and it will get darker from there.
The jump around 52 sec in your video is strange. This looks like something weird happened in the ISO override behavior, making the effective ISO jump very suddenly. I'd be interested to know if you can see what image number this happened on. From the log, I'm guessing it was around 2205, where the ISO went over 1000. The brightness measured in the raw data drops by almost exactly 1 stop at this point. This may be similar to an issue we've seen on g1x.
This is also around where the "busy" must have started, because because the "sleep" time drops by 0.6 seconds.
If you want to investigate the ISO response further, I wrote a test script for that:
https://chdk.setepontos.com/index.php?topic=12165.msg123561#msg123561 But for now, I'd suggest keeping the rawopint ISO limit below 1000 on this camera.
For this test I set maximum ISO to 1600, which in retrospect looks too high and I should have left it at 800. Also minimum Tv was 1 sec, would setting it to ½ sec have help achieve underexposure at night?
You can make it get dark if you set the exposure limits high enough, but it will happen very suddenly, because the script tries to keep the scene at "correct" exposure right up until it hits the limits. Bv/Ev shift gives you are more natural progression.
Even at 1600 ISO 1 sec the sequence was able to hold at a 3 second interval, so processing of each image didn't take longer than the interval which surprised me, since I was seeing "BUSY" on the screen after each exposure once it got dark. Wonder if it would have been the same if the interval was shorter?
You can use the "sleep" column in the log to check how short an interval you could get away with. In your last log, it ends up at about 1 second, so with the settings you used, a 2 second interval would probably have worked. If you kept the ISO below the point where it triggers the busy, you could use around 1.5 second. You could also use the available time for longer exposures (e.g. 2 - 2.5 second), but somewhere over 1 second Canon dark frame will kick in, which effectively doubles your exposure time. You can force this off in CHDK options.
The BUSY screen is shown both for high ISO noise reduction and Canon dark frame.
