Thinking about what srsa_4c posted, were you doing the test yesterday in different lighting conditions?
No. I tried all sorts of different light levels to get it to replicate but the zebra now seems sound as a bell. It did clear up after I had connected to chdkptp and got chdk to work as per a previous post.
Anyhoos, I had a good day testing the md_get_cell_abs(col,row) function and my test script is attached. It does nothing but sound the shutter when motion is detected (trigger) and beeps when the scene returns to its original state (release). It also has a timeout in case the scene doesen't return to original levels. At every event, it writes a table of original, trigger and release levels to a log file in your current capture folder. I found it to be very accurate when detecting even small birds and it only timed out a few times. Thanx mucho for this.
You can set the usual md parameters as well as the timeout duration and the 'release' threshhold level. Use this threshold to filter out scene noise. For example, a value of 15 means that all cells must return to within +/- 15 of their original levels for release to be called.
I am going to play some more with this to see why it sometimes times out but I think md_get_cell_abs(col,row) is pretty near working as is.
Dave