Measuring ambient light

Factual Questions
1

I’ve just installed a new monitor, and am in the processes of calibrating it. The instructions say “Lower the light in the room to under 64 lux. Ideally, the ambient light level should be approximately 16 lux.”

What is a “lux,” and how do I measure it? And why wouldn’t a completely dark room be better?

2

Just go out and buy a photometer. This one is only $472.50

3

If you don’t want to buy one, you might try going to a high-end photo shop and see if you they’ll rent you a unit.

Here in the Chicago area, Helix will rent you a Gossen Pan Lux II for $12.50 a day (with a $714 deposit…).

4

Unless you have a photometer you’ll just have to guess. One lux is one lumen/m[sup]2[/sup] which probably doesn’t help a bit.

Unless I have screwed up my conversions factors, the recommended light in the average office is about 50 lux so unless your room is brighter than is normal for an office you should be well under the 64 lux called for.

5
  • I have been looking at multimeters lately–as for a project I need one that does temperature, and would like a freq counter also. What’s surprising to me is that some brands of DMM’s are nearly identically priced everywhere (Fluke) and others you will find differences approaching 50% (Extech).
    ~
6

Thanks for the input, guys.

Actually, I’ve discovered that during the calibration process, the software supposedly tells me if there’s too much ambient light (don’t ask me how it knows). It didn’t tell me anything, so I’m assuming it’s ok.

And I’ve decided to install a dimmer switch, to lower the lights when I’m on the computer. It’s a whole lot cheaper than a photometer.