I think Fable Explorer can fix this. Anyone used it before?
EDIT - Under CAMERA MODE. They have all the different camarea values and their fovs. I think you can just change them and have Explorer make a mod.
Fantastic job picking up on that Tanuki!
I gave it a whirl, although this is my first time ever using the program so please excuse any discrepancies.
This is what I did:
1.) Extracted the program into the Fable installation folder.
2.) Opened up Fable Explorer and under the CAMERA_MODE subset, selected "CAMERA_PC_NORMAL" and increased the FOV from 90.
3.) "Appl[ied] Changes" and then saved the mod and launched the game from the toolbar menu.
Fable Explorer has an alternate DirectX9 dll, so it didn't get along too well with SoftTH. Without SoftTH it worked well, and when SoftTH was initialized after Fable Explorer everything worked fine.
I tried out four FOVs for the main camera. 110, 120, 130, and 150. 150 was the result I got from an online FOV calculator for a 4.8 AR, 110 was a conservative estimate, 130 a good midpoint, and 120 seemed to be the best. Looking at the shots now compared to the original 4:3, I think that somewhere between 110-115 would probably be correct.
110
120
130
150
A note: Adjusting the FOV through only the "CAMERA_PC_NORMAL" variable only changed the field of view for (obviously) the main camera. In order for this to be a usable hack, all of the other camera variables would have to be changed. In the brief time that I messed around with this, all of the cutscenes still had a very restricted field of view.