If you're referring to Ansel Adams' Zone System then yes I still use it to meter a precise exposure in both digital and film. How I meter in digital is different than how I meter in film, but the Zone System can be used as a foundation for either.
How do you use the Zone system in digital?
I'd be interested in hearing details and procedures on how one arrives at the Exposure Index that one rates one's
digital Black & White negative film at, to do one's shadow-tone light metering using one's hand-held reflected light meter. And also, about what percentage of normal film development times one uses to arrive at a suitable film-development time to get those perfectly dark-but-yet-detail-revealing Zone I and Zone II Black & White negative zones in the final darkroom silver-gelatin print. Oh, wait...the digital camera shooter does not shoot Black & White negatives, and does not develop negative film in liquid chemical solutions with controlled strength, controlled temperature regulation, and controlled chemical agitation, and does not control film gamma (degree of contrast of the final negative) to make a darkroom silver gelatin system enlargement (a projection print or contact print).
We're not projecting light through silver-based negatives to make prints based on negative data [black negative areas turn white!], but are working in a positive system, more like color transparency film. And yet, NOT really all that much like how transparency film is developed to one, final "correct" development degree.
Careful light metering using a color-positive digital camera is not using the Zone System. Electronic images that are not contrast-regulated by the developing solution's strength, its time, its temperature,and the worker's development agitation routine are not made using Zone System methods. Again, careful and consistent light metering and exposure determination is not using the Zone System.
Perhaps it's time for some type of new description of how skilled workers perform light metering and exposure setting routines for their digital exposures? In the 1980's, we referred to this as "pegging the highlights", which is using the light meter to determine the brightest tones we wanted to look bright, but which we did not want to "blow out" through over-exposure. With a Nikon and 12mm scribed viewfinder circle and Nikon's traditional 60-percent/40-percent metering, this would involve swinging the metering circle up to the sun or light source, and placing that just outside the 12mm scribed circle, then metering, then setting that exposure or closing down the lens diaphragm to anywhere from 1/4 to 3/4 of an EV value, OR alternately, using an incident light meter (you know the one one's with the white frosted hemispherical dome) and setting that meter's suggested reading (with some wiggle room), in order to "peg the highlights". That however, was not Zone System either, because we were metering highlights, we were not regulating film development, and we were not controlling the film gamma (degree of contrast) through development.
In digital imaging, there is an entire list of things that Minor White and Ansel Adams never saw in their lifetimes. Thinking that we are using their film- and chemical-based and time-based and agitation-based 1940's-era working methods with twenty-first century digital cameras is an erroneous understanding of what the Zone System truly was and is. Oh well, I've said my piece about this for the last time (in this thread at least). I think I shall retire to the sitting room and listen to some phonograph recordings on the Victrola while my beloved prepares a roasted chicken supper from the chicken we raised and butchered yesterday. We have also just recently taken delivery of a parcel containing a bottle of fine French wine that we ordered by postal mail and which recently (a month ago) arrived across the Atlantic by way of ship's cargo for the princely sum of $2.19 for the wine and trans-Atlantic shipment. Oh, what a fine supper we shall enjoy!