How much light do I have? - Page 2 - Orchid Board

Ross · #11 09-24-2008, 05:16 PM

Everyone please keep in mind this is very approximate. Not accurate at all. It gives you about the same info as the sharpness of your shadow technique. Nothing beats an accurate incident light meter.

Ray · #12 09-25-2008, 08:56 AM

Also, make sure that the piece of white paper (the higher the brightness, the better, but not critical) completely fills the frame.

This calculator allows you to measure light only fixing the ISO setting at 100, allowing you to vary the f-stop as needed:

Light Intensity Measurement

BikerDoc5968 · #13 09-25-2008, 09:10 AM

Thanks, Ray. I'm sure this will be better than anything I've posted to this thread

blackorchid · #14 09-25-2008, 09:10 AM

lol...I have no camera and no experience with camera so I don't know what is f-stop, ISO, and exposure...yeah, I know it sucks...

SheilaJ · #15 09-25-2008, 11:37 PM

If you're talking about the heavily tinted windows, they do reduce light a lot. I work with plants in office buildings with tinted windows and it definitely cuts down the light.

I would suggest you buy a $25 light meter. It will be worth it if it keeps you from buying one or two orchids that won't do well in that window.

Brooke · #16 09-26-2008, 05:10 PM

The windows don't have to be heavily tinted to get a drastic drop in fc's through them. Through the pane of a window with a screen, the light can be intense at the edge of a normal windowsill . Taking a reading one foot back will cut the light drastically and two feet back, you are about 600 fc's. Sorry I don't remember the middle fc number but I did the test a couple of years ago.

For my display area inside the house, I had to add CFL type lights to get enough light to my long blooming plants to keep them growing in adequate light.

A $25 light meter will save you from guessing about the light you have coming into your grow area.

Brooke