Thanks for the reasurance I thought I was on the right track.
The LDRs Im thinking at using look like they will match fairly well. The turn on response time is a little slower 20ms compared to 2.5ms ant the turn off is vitually identicle. I'm thinking that the 20M res in parralel should actually speed up the turn on response a bit by making the response curve similar to a reverse audio pot rather than linear.
Ill have a play with it all on breadboard I think before hitting the pcb
The LDRs Im thinking at using look like they will match fairly well. The turn on response time is a little slower 20ms compared to 2.5ms ant the turn off is vitually identicle. I'm thinking that the 20M res in parralel should actually speed up the turn on response a bit by making the response curve similar to a reverse audio pot rather than linear.
Ill have a play with it all on breadboard I think before hitting the pcb