The search for a T stop database for still photography seems like an answer in search of a question. After you found the information you would then need to find out how accurate all of yor cameras are at the standard shutter speeds and variable speeds. Then you would need to test all of the meters to see how far off they might be. A teacher in High School once told me that if you considered the difference between T stops and F stops and then added in shutter speed variables and chemistry measuring variables and thermometer accuracy variables you would think it's just about impossible to get a good end result. In practice these variables tend to cancel each other out. If you have a lens which was marked with a maximum aperture of f/1.4 but measured T 1/.53 in a particular test, your example might measure T 1.59 or T 1.37. It is probably not practical to test every single lens for T transmission. If this were a serious problem we would have known about it a long time ago. There is the additional issue of the uniformity of the transmission. A fast standard lens will typically have some light fall-off at the corners close to or at full aperture. Should we then measure T transmission at different points of the field of view?