in camera meters do an acurate job, especially if you have and use the spot meter for measuring the subject brightness range.
If you go with studio lighting, you will need an incident meter to set exposure and adjust the ratios.

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If you go with studio lighting, you will need an incident meter to set exposure and adjust the ratios.

This was certainly true with film, but not so much with digital. Digital cameras have instant playback so with a couple of test shots, very accurate balance and exposure can be achieved by trial and error. Less elegant than waving a meter about, but more effective. The histogram is without a doubt the ultimate light-meter readout. Since you can actually see the shot within a moment of taking it, fine tuning is very easy.

Even with the best of lightmeters, product photographers shot at least a polaroid or two before switching to film in the studio or on location.

In the portrait studio, exposure varies within very narrow margins, and apertures rings get very little exercise after initial shoots that determine the studio settings. This would be as true with digital as with film. Levels set on the main, fill, hair, kicker and background lights are rarely changed in most studios, and distances from the subjects remain pretty constant. Going from head-shots to full height shots, including moving the light back, was about the difference of a stop. The shooter quickly learns to set the lens at f-16 for the head shot and f-11 for the full length if that is what the combination of ISO and light provides in that studio.