digital SLR camera as light meter on film shoots

This is relatively uncharted territoty, I suppose, but some DPs are using this technique on a fairly regular basis (Don McAlpine, amongst others).

The problem with it, generally, is that a digital SLR is not giving you a "true" ISO, and therefore the images are "acceptable proxies" at best.

So the argument goes.

So everytime I go out on a film shoot, I would shoot a series of stills on a digital SLR (D70s, in this case), and compare the difference in the telecine.

So far, the results have been practically spot-on.

The most interesting examples have been when using Kino-flo lamps for lighting, which regularly read as 'under' on a light meter, yet turn out brighter than the said reading when the image is viewed.

The image above was captured by a D70 with the same settings as the motion picture camera. My light meter was reading the subjects highlights as fairly low (about a stop and a half under) .