If you are a serious orchid grower and..
 

If you are a serious orchid grower and do not already own a digital light meter. Please go purchase one. The hydrofarm meters are like $40 off amazon. I just received mine today and it was a very enlightening experience. An essential tool in the growers arsenal! :waving

Heck, I'd second that conclusion, even if one isn't nearly that serious.

'tis amazing, what a little light-o-meter can bring to one's reality, isn't it? ;)

I concur about the use of a light meter! I recently bought the hydrofarm analog light meter and have been having good luck with it. It definitely has answered a lot of my lighting questions.

Light meter smartphone apps are free or $1-2. I have two on my BlackBerry, and they concur pretty well. All current smartphone platforms have them.

Two other devices you should buy are a pH meter and a TDS meter. Adequate models cost $10-15 each on Amazon, and smartphones haven't progressed quite this far yet. Your water quality and fertilizing practices will be eye-openers.

You can also use cameras and the EXIF data on your digital pictures to work this out, particularly if you take a picture of a "neutral" coloured object.
Orchids on a Balcony: New Gadget: Light Meter
I collected some common foot candle requirements for orchids on that post.
There are free apps too, but I don't find they're as accurate as cameras.

The formula to work out foot candles from a camera is:

6*F^2/(I*E)

where F = F stop (aperture)
I = ISO setting
E = Shutter Speed (exposure)

I've seen a lot of free light meter apps for Iphone.

But I don't have any analog/digital light meter to test the accuracy of them.

Maybe one of you could try them out and compare them to the real light meter results?

Oskar

I got a nice light meter from where I work for $4. It was a discontinued item I found in the back warehouse.

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I'll compare an app with the meter today.

It is not that I am cheap, but I am a professional substitute teacher, and I found one at 1000bulbs for as low as 19.67 US dollars. (In the USA, I guess). Anologue.

I admit, I never intend to get one. I have always grown plants in the windows so, with orchids, I can pretty much figure out what light I can give them where. However, if you have doubts about your lighting, it seems as though it would be a great idea.

Yeah, i use this method too. Unfortunately, all my orchids are fighting for the brightest spot.