This is a simple post to explain why the people are usually blurry inmy lighting photographs. As an illustration, I took three photos of a speaker on stage, using different exposure times. An exposure time of 1/40 second produces a sharp speaker, but an overally ugly picture because of the noise in the image. Look at the graininess that is visible in the full-size image.
Exposure time 1/15 second:
Exposure time 1/5 second:
At 1/5 second the noise is gone, but now the exposure is so long that the speaker moves during the exposure, producing the “halo” effect. Since my goal in taking these picture is to showcase the lighting, I use a longer exposure to capture the darker parts of the image, and I live with the fuzzy people. Another option is to get a more expensive camera with a more sensitive sensor and a broader range of apertures (my camera only supports two).