How to control light intensity in biological experiments?

Question

I just had a question in school about designing an experiment to measure the effect of light intensity on the number of stomata.

My question is only about controlling light intensities...

1. Should I use the same lamp but put it different distances away from the plant?

2. Should I use light bulbs with different values for power?

Answer 1

The best light for stomata operation is the UV grow light ..unfortunately this is a ballasted lamp that does not respond well to a dimmer...but you can get a dimmer for all the others and lower light levels in increment's evenly ...most dimmers come in 600 watt versions and are pretty easy to hook up,,,moving the light around will cause the photoreative sensation of the plant ot work overtime and might blow the whole test.....have a good un...from the E