Question
Wayne,
I've been reading a book on orchids and it talks about foot candles in regards to the amount of light an orchid requires. I currently have some Cattleyas, Phals, and Vandas.

I read that the cattleyas requires about 2,000-3,000 foot candles while the vandas require 6,000-8,000; I am not sure about the Phals although I think I read it is about 1,500-2,000.

Question: How do I measure foot candles? I've read a bit about using a camera, I have a Canon Rebel XTI camera which I may be able to use.

Please let me know if you've measured foot candles before? if so, have you used a camera for it? any other method?

I live in Orlando, Florida and am interested in providing a "happy medium" for my orchids.

At the moment, my orchids are not showing any spikes yet despite the fact that I've been feeding it Better-Gro bloom booster once per week for the last month and a half which I will continue until the end of March. I am planning to go back to 20-20-20 which is what I typically feed it once per week. I just moved them out to my patio, from my garage, given that the temperature is up to 70-80's in Orlando with the low about 50-55.

Thanks as always for your thoughts, comments; I greatly appreciate those.
Angelo

Answer
Good to hear from you Angelo.  Using your camera, set the ASA film speed at 200, set the shutter speed at 1/125 of a second  Focus on a white paper near the plant so only the paper is in focus. Adjust the f-stop until you have the correct exposure as shown in the light meter in the camera.  This method is somewhat limited for higher light intensities.  An f-stop of f22 is 2,000 f.c; f16 is 1,000 f.c.; f11 is 500 f.c.; f8 is 250 f.c..  To measure higher light intensities you may need to find an outlet for light meters by googling that topic.