Do you have access to a goniometer? This is the tool that will let you measure both light output and intensity at point location and total area, there are several, scan goniometers, image processor ganiometers, etc.
Visit this link to Barco's website. It has a useful explanation of measurement methods. We use many LCD and CRT projectors in our applications and the practical value of CRT lumens is usually much lower than the manufacturer's spec. This is because the brightness is expressed as a peak value; something rarely attainable in practise.
A pocket lightmeter and a flat matt white screen are all you need. You can then easily convert illuminance readings to lumens values if you assume the screen has a lambertian gain.
The goniometer measures ANGLEs, the gonio-photometer the
light vs. angle.
Lylek:
How much accuracy do you need ? Do you want to hust compare two projectors or do you need more detailed data e.g.
intensity vs. x-y coordinates ?
Do you need only one measurement or do you have to have
the instrumentation permanently attached?
