In the end I did find a program which will automatically convert a series of jpg stills to a video. VideoMach is a fairly versatile program. It is possible to adjust colour balance, add text and resize or crop amongst other facilities. The program can be run for free. All functions work. The only thing different is that it adds the program name to the bottom of the first second of the final video. Not a great problem. VideoMach produces an Mpeg1 file and YouTube didn't really like that so I used Ulead Video Studio 11+ to re-save it as Mpeg2.
My second attempt was clouds again. I decreased the time interval between photos to about 1 every 11 seconds. It still looks jerky but I think that is partly due to the speed the clouds were travelling across the sky.
I tried another batch later on with 1 shot per 5 seconds and that looked a lot better. Unfortunately the series was not very long as the camera battery ran out. I must remember to turn off the camera LCD screen to save power. I think another problem I have found is in the circuit design. The 555 timer chip is voltage sensitive so the timing will change as the 9V battery runs down. I have a solution for that which I will try later but it involves using a larger 12V gell cell - no so portable!
4 hours ago