Set your shutter speed to 1/50th of a second (1/48th if possible). If you like the reading on your meter and not on your DSLR, trust your meter. Set the color temperature to the same as the film stock you use, compensate for any filters ie 85, 80. If you're using a camera equipped with Nikon lenses such as a Bolex or Eclair, you can put whichever lens you're actually shooting with on your camera as well so you get a closer color rendition, unless of course, you get the EOS.
Also set your ISO the same as the film you're using. e.g 500 for a 500 speed film (though some cameras only do 400). And then, when in dout, trust in the Neg. it'll have a lot more room than a DSLR will in my experience.
Generally you buy which camera you have lenses for, and can afford. Myself, I'm a Nikon man, always have been. Others like Canon. In the end, they'll both work well for what they do; take images, ya know?
Myself, I have an FM10 and an F4, from my film days, normally when I go out on set I have my AC bring out her own D40 which isn't a bad little camera, though there is a crop factor. I've also used the D80 before and the D2 (IIRC). I like the Nikons, a lot, but I find with all DSLRs they they are quite confusing to work.. in terms of changing settings etc.
I've had a Nikon D50 since 2005, and love it. The thing's built like a tank, which for where I'm generally working is good. I've dropped it mulitple times, left it outside for a month at -30 with no loss in battery, dropped it in snowbanks, taken it into volcanic ash, glacier silt, and pouring rain, coast to coast, and it's still clicking away, taking beautiful pics. My father had a canon EOS, and after one drop, it was toast. Nikon man here.
I use a Canon EOS REBEL XSI, on the set. I use to check exposure, lighting contrast, how different color temperatures will look. I also use it to record complicated set ups and just fun shots on the set. The 3” 230,000 pixel LCD screen is the same screen on the highest cameras and makes it easy to use as a view finder. It has been a great fun tool. It is a cheaper DSLR in the Canon line and is not as flexible with regards to some of the adjustments. The camera is super light, weighing in at 17 OZ, it’s half the weight of the D50.
The toughest part of using the camera is the lens is a T3.5. So if I’m, shooting at 400 ASA at 1/50 of a second, at a 1.4 on my motion picture camera I have to do some mental gymnastics to convert the stops to work with lenses that open more then 3.5.
It has a chip the size of super 35 so the lenses are really more accurate then DSLRs that have full 35mm size chips. I believe that means 35mm still negative size which is really vista vision.
Thanks for all the tips and insides on your on-set DSLRS.
Being very much into Photography as a hobby, I will wait for the Nikon D400 to come out mid 2009, so I can get the D300 for cheaper!
I use a Nikon D70 and, like Bob, prefer the "crop" sensor size because it more closely matches 35mm motion picture film in size. They're also pretty close to the RED sensor size if that matters to you.