Recent content by jodyflorian

Sorry for the physiology post :p Thanks - now I know what to look into next :)

Hiya, While learning about photography I've realized that there's something I can't explain with the physics I was taught at school. What I do know is that pure red, green and blue have specific frequencies. And that combining the colours produces white. And although I don't know exactly why...

Lol @ popcorn paint. Brilliant - now I know the term! "Integrating Sphere". I'm just trying to find the cheapest way of measuring laser output so I can judge lasers that I buy off ebay, and optical power meters seem to go for no less than £150 so about $250. The main hurdle I'm coming up...

Forgot to mention... Already discussed trying to do this with the Lux meter at: https://www.physicsforums.com/showthread.php?p=1941217 But the accuracy due to unknowns was becoming a problem - a Lux meter just doesn't seem useable.

Hi, I've decided to make my own meter for measuring laser power to around 10% accuracy if possible. Optical power meters are way too expensive for me though. One building block I've decided to use is a phototransistor, because I've found one which has very good linear response - when measuring...

Thanks Andy! I think I follow, or at least I think I will once I have a good look over it lol... So do you think I could get some fairly reasonable accuracy by using the lux meter? If it helps to know, the lux meter has a translucent circular aperture with diameter 40mm, and the laser...

Hiya, Question 1: (Main question) I bought a lux meter while understanding very little about how light is measured. I'm hoping to measure the output of a laser in mW. I assume it's possible to do this at least to an accuracy of about 10-20% which is all I need? If so, please could someone help...