My front door is near a corner. One wall is perpendicular to the wall with the front door. That perpendicular wall is about 18" from the door's frame.
So I have a 90 degree situation. Imagine standing in a corner where two walls meet, and looking outwards. 90 deg H FOV.
No need for a 2.8mm lens, with 110 degree H FOV. I bought my 2.8mm cam as a newbie, so I'm making the best of it. The cam is mounted near my front door. The 110 deg FOV has both walls in the recorded image. Wasted pixels, left and right, to make sure my siding stays safe and sound? lol.
Even a 3.6mm, w/ 87 degree FOV, would have wasted pixels. The 1.5 degree slice of missing H FOV by both walls doesn't contain valuable coverage.
Re: Vertical FOV: There are 2 steps leading up to my front door. Even with the 2.8mm lens, it was a study in compromise to aim the cam vertically. If I aimed high, to see long, I'd crop the bottom of the FOV near the door. Well, that means I couldn't see packages that were left by UPS, Fed Ex, etc. If I aimed low, then people's faces were clipped off in the medium distance. Nevertheless, I'm happy with the result.
If I were to do it again, it would be 3.6 or 6mm
Suggestion:
Consider "corridor mode", and rotate the cam 90 degrees. The VFOV angle becomes your HFOV angle.
I have yet to follow my own advice, lol. Some experimentation is needed. I use Smart PSS on a clamshell in the kitchen to keep an eye on things. I'm not sure how a rotated rectangle (corridor mode) would fit inside the multi-camera Smart PSS display....
Fastb