How Can I Make Beam Optimization Experiments Easier?
1. Switch to red LEDs and use your eyes to optimize. This can be a temporary or a permanent switch, depending on whether red light will work in your application. Very high output red LEDs are available. If you're going to switch back to IR after the experiment, be sure to choose the most similar red LED in terms of angular specs.
2. Obtain an IR viewing card. Radio Shack used to carry them....don't know if they still do...Edmund Scientific, Kodak. This will make your IR visible if you use enough LED drive.
3. Obtain a cheap monochrome CCTV camera, e.g. a security camera. They generally have good IR sensitivity. If you put a visible blocking filter (Wratten 88 or 89 or similar) over the lens or CCD chip, the camera will only pick up near IR. Use this with a monitor to see the beam!