Selecting the Right Sensor Range

I would think some basic work on the optics was the start point e.g what angle are you going to collect light from ?
The other thing I'd be looking at is differential vs absolute?
After that some empirical tests should give some idea of working range.
Del

Yep, this is a case where a bit of guess work and a lot of fun playing experimenting and testing are in order. Fortunately there are a limited number of sensors of these type available so its not too confusing, difficult or time-consuming an approach.

I think the lecturer would also agree.