I've been looking for an affordable lens I can use for nighttime shooting, including astrophotography. The two lenses I have found that seem best suited for this are the Samyang 16mm f/2 and the Samyang 14mm f/2.8.
Simply looking at the aperture it seems I would get another full stop of light from the 16mm f/2, however looking at the charts on DXOmark I see that the 16mm has a transmission of 2.4TStop while the 14mm has a total Transmission of 3.4TStop.
I don't know much about transmission, is this simply because of the wider field of view of the 14mm, with the 16mm still providing more light considering only what's within frame of it. Or would the 14mm actually provide more light overall, perhaps due to the quality of a higher quality of the elements within it despite the slower aperture?
Succinctly : If I where to shoot the same image with both lenses at the exact same settings and crop the 14mm image to match the 16mm, which would be brighter? Why?
I wonder if it might also make a difference that the 14mm is full frame whilst the 16mm is specifically designed for APS-C. (I would be using an APS-C format camera for reference, 700D)