Today i'm gonna show you guys the diference between those numbers that can be a little complicated.
First: i want to talk about T stop, that represents TRANSMISSION.
Transmission, means how much light come in to the sensor!
Found on the most part in Cine lenses, like that:
F stop in other way, is a mathematic count that represents how bokeh this lens produces.
Is relation between focal distance and aperture of lens diaphragm.
Here, the same lens with T stop and F stop different: F/2.8 and T-stop 3.3