In the past I ahve built beam breakers using laser and LDR’s or IR led transmitter / receivers where my targets are opaque and of a reasonable size.
To explain my ‘new’ requirement. I am into macro photography which means that my targets may well be insects in flight. Given this target size I visualize the need to create an area or ‘window’ where anything passing through that plane of focus will trigger the camera. Let us say for example a plane of 1 metre x 1 metre in front of my camera at a distance of approximately 600mm from the camera itself, this last distance is not critical just for illustration.
Previous projects worked well where the target was of a reasonable size e.g. a bird in flight, however an insect will be very much smaller and if a beam breaker is used the beam has to be incredibly narrow to ensure it is ‘broken’ by the target passing through it - but the ‘window’ area is large in relation to the target so multiple beams would be required.
My thoughts were to use lasers and LDR’s - if only I can narrow the laser beam sufficiently. To create adequate coverage a laser ‘curtain’ / ‘mesh’ would be required.
I then tought about proximity sensors - but I haven’t experimented with any as yet and, in the current crisis, have no means of getting any to experiment with.
I’d much appreciate any thoughts, insights / recommendations - is it even feasible?