How do i know how wide my lens is??

[eravedesigns]

ya sigmas site does say for digital only. Just comparing images i have taken with my sony lens too compared to that 20mm 2.8 the 20mm is much wider. I even talked to a photographer for the Journal Sentinal and she told me that her zoom 17-24 (somethign like that) had a 130 degree angle of view with no distortion. The sigma would still be wider than the sony. Yes I suppose the focal length does affect the FOV but each lens is also designed different. That sigma has an 80mm filter size so to me the lens itself must be wide there for making the light it can take in much wider. That was my impression