Is it worth using a digi slr *hiss* to get a representation of the exposure or will there be a difference?
I would talk to the lab first, ask what they are doing. Some of these places, like the local one here, seems like a new employee every time and if you start talking about pushing and pulling and filter factors, they don't have a clue. Chemistry gets old, too. It sounds like you have thought things out to a reasonable degree on your end, so I would ask them about it.
Using a digicam as a kick-butt light meter might seem like a good idea, but until you spend some serious money, the light meters in are really among the weakest link in gettting a great exposure. It won't necessarily extrapolate to your film.
The light meter in a digi slr will be as good as any other in camera lightmeter but the big difference is that the digi slr will have an acceptable contrast range. Maybe 10 stops or more. Slide film (positives, chromes) is high contrast film and only accepts 5-6 stops depending on which film. Some maybe a little more.
Originally Posted by Jarvman
So whilst with a low contrast subject a digi camera may show the subject as flat, the Velvia may show it as just right or quite contrasty. There is no direct comparison as a digi equates to medium to low contrast film whereas as slide is high contrast. Electronics may fiddle with that but you have to know exactly how your camera works to be sure of that.
If you are a zone system person, then you will know that there are 11 zones. 0 thru 10 and each zone is one stop. With slide film which only has a range of 5 stops you can make each zone 1/2 a stop. Because slide film is so high contrast, a small change in exposure makes a big difference. Infact about twice as much difference as on black and white film.
Read what poisson du jour said carefully.
I agree wholly with rob champagne. Many digi photographers take the image on the external LCD as gospel, which in fact is the wrong (or lazy) approach. That display only gives an indication of the dynamic range of the sensor and where the image being framed fits into it. It bears no relationship at all to real-world metering with transparency film which, as rob points out, has a perilously narrow latitude. If you photograph a waterfall with a digi, there is a very good chance of highlights in the water clipping. With tranny film (notably Velvia), this clipping is much more graceful and subdued. I wouldn't personally trust a digi meter no matter how sophisticated or accurate it is touted.
Lastly, be aware that in digital cameras that image is nothing more than a complex mathematical interpolation of three primary colour channels. With film, the image is captured direct to the medium in a way that has remained fundamentally unchanged for more than a century. I sitll prefer either my EOS 1N's meter, my Sekonic L758 with a contracted Zone System (11 zones to 5 in 0.5 as rob points out) or a 'guesstimate' i.e. "f8 and Be There!"
.::Gary Rowan Higgins
One beautiful image is worth
a thousand hours of therapy.
"It is horrifying that we have to fight our own government
to save the environment."