Light Meters for Dummies

[WaterWitchin]

I figured if I whined you'd chime in Bill. So I add the appropriate number of zeros to each... none, one zero, or two, and it gives me footcandles. Right?

And if so... when I'm at the bottom (the 1-199)... why even have that option? Wouldn't it be easier to just have the x100 and move forward? Who wants to measure 1-199 footcandles in the first place? Or even the next level? Just a bells and whistles thing so you feel like you've gotten something for your $18?

And I'm feeling kind of de je vu-ish... like maybe you've explained this to me before, and I just didn't get it the first go-round. Regardless, thank you.

[Ray]

Originally Posted by WaterWitchin

I figured if I whined you'd chime in Bill. So I add the appropriate number of zeros to each... none, one zero, or two, and it gives me footcandles. Right?

Correct.

And if so... when I'm at the bottom (the 1-199)... why even have that option? Wouldn't it be easier to just have the x100 and move forward? Who wants to measure 1-199 footcandles in the first place? Or even the next level? Just a bells and whistles thing so you feel like you've gotten something for your $18?

The photocell has a non-linear output, and theoretically more precise in the meter’s output if in the correct scale. They don’t make that meter any longer, so I don’t know the specs, but for the sake of argument, let’s say the accuracy is +/- 5%. In the lowest scale, that would mean your reading could be as much as 10 fc off. In that highest scale, it could be as much as 250 fc off, so if used for really low light levels, your potential error is greater than the range.

It’s a cheap, unreliable meter. Let the grandkids play with it.