Interesting to know. T stops insure that exposures made with any
of several lenses will match. Depth of field is a geometric property
so, unless all the T stopped lenses have about the same difference from
the f/stop the charts won't be quite right. In any case, depth of field
is very approximate, that is, it really has no fixed definition other
than what is perceived to be sharp, so variations in charts, unless very
large, are of no consequence. In most cases modern motion picture
cameras have through the lens reflex finders so one can see what the
depth is visually rather than guessing from charts.
On 8/18/2016 1:31 PM, bobkiss caribsurf.com wrote:
DEAR RICHARD ET ALIA,
As I still do some work as a director of photography on film/video productions and teach film/video production, I can state that video/cinema lenses intended for professional production are still calibrated in T stops. The local production houses' lenses are calibrated in T stops and the Barbados Film and Video Association has a lovely set of brand new, coated prime lenses for their Black Magic 4K cameras, all calibrated in T stops.
Further, depth of field tables for cinematographers are also calibrated in T stops and meters and/or feet. I just viewed some tables for Zeiss prime cine lenses.
CHEERS!
