Question Regarding the New TS-E 17 f/4...

[ShutterbugJohan]

I have also wondered this--it seems strange that the front element looks more like a 14mm. The 16-35/2.8L and the 17-40/4L certainly have smaller front elements...

[Colin]

I would assume that it has something to do with the tilt/shift mechanism requiring more angle of view to operate, but I really have no idea, just a guess. My assumption is based on things like zoom lenses requiring a lot more glass to achieve a given aperture diameter. It just seems like the variability requires more room to move around, optically. But, again, I have no idea.

[Dann Thombs]

One of the marketing points for the two new TS-E's, was a larger projection circle. This is needed since the lens will be moving around a bit, and you don't want light drop off near the edges of the extremes. So I imagine you'd need a much larger front element to achieve that.

[alexniedra]

This is what I was expecting. I have noticed obvious light falloff when using view cameras to maximum shift.