EEVblog #364 – LED Ceiling Panel Lighting InstallPosted on October 4th, 2012 8 comments
Installing Doug’s 60W diffused ceiling LED light panels in the lab.
And a look inside a typical office ceiling crawl space.
Wow the video looks much nicer with more light!
wouldn’t it be bether to keep at least one of those two panels more or less mobile so you can bring more light at specific spots you may ocasionally need it more?
Pretty sure the pun was intended.
FYI Dave – you should get some T-bars for your half-tile panels so they’re supported in the middle. They just rest on the short sides and give some support (you’ll see them on the light fixtures because your fixtures are half-tile width).
As for the F-stops, going from f/2.4 to f/4 is a halving of light. f/4 to f/8 is much more than half (I think it’s f/5.6 is the next halving). Remember, shutter speeds, ISO, and F-stop are all inter-related and one “stop” refers to adjusting light by half or doubling. (E.g., shutter speeds are 1sec, 1/2sec, 1/4sec, 1/8sec, which halves the amount of light as you go down and doubles as you go up). ISO is similar – an ISO200 sensor requires half as much light as a ISO100 one, etc. F-stops are similar, but remember they are fractional – the focal length of the lens divided by the number gives the diameter of the opening (not the area). Halving the light means the area decreases by half, which narrows the aperture (increases the number), but not linearly because it’s a square relationship (multiply by the square root of 2). So it’s f/1, f/1.4, f/2, etc.
The color rendering is very poor and the color temp. is too high.
Video looks washed out colors look pastel.
I have some of these flat panel lights and have replaced the LED boards with MCPCB’s with Nichia High CRI 083′s.
Got a CT of 3500k and CRI of 82
Also,I designed a linear driver to eliminate the modulation in the light output.
Get a solar cell and scope the light and you will see modulation even with it set to full power.
If your goal is quality video, these lights are an eye soar thats fit for the pit!
I still think you need task lighting, say, under the first shelf, to illuminate the nether region of your workbench.
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