I'm sure some of you have this, but either way, figured I'd share this spreadsheet I put together.

What is nifty about this is once you enter data, you can enter information abour your setup and store it on another sheet for comparisons and reference. Also once the data is entered and calculations are done you can cut and paste the results right into the forum and post your results!

Pictures are taken from the Pgen program, we can thank Paladan for the pics!

Enjoy, let me know how you guys like it

Click to view attachment

This is super usefull. Now if only i had a real lux meter. Im curently useing a devise that tells you the exposure value for a camera and then converting that to an estimated lux.

Unless you're attempting to out-lumen someone that meter will do you just fine. Primarily a meter is used to verify when you've achieved maximum output for YOUR build. So, going with that line of thought, it only matters that any given meter works and not that it gives precision numbers.