When using these lenses, would you just leave the camera set for wide FOV, which gets you the full 95ish degree FOV? Using Medium or Narrow would result in a rather small image and be fairly useless? Is my understanding correct?
yes, that's the whole idea with these lenses - to be able to shoot at Wide FOV because then you utilize full width of the GoPro sensor.
when you shoot at Medium FOV you are "wasting" the un-utilized portion of the sensor :
it seems to be the case that drone hobbyists settled for the +/- 20mm-24mm focal length as ideal for aerial photography/videography (that's in 35mm film equivalent), this is why we set GoPro stock lens to Medium FOV (that's about 21mm equivalent) at the expense of wasting part of the sensor.
Manufacturers that make specific cameras/lenses for drones also seem to have settled for these type of lenses.
with the GoPro sensor size 1/2.3" this (20-24mm equiv) translates roughly to lenses 3.50mm to 4.2mm that we are trying to use in GoPro.
3.80mm lens utilizing full width (Wide FOV) of the GoPro sensor is 21.66mm equivalent.
Such lenses are easier to manufacture with minimal distortion, they give us FOV that makes drone legs and props not visible in the frame and yet are not too narrow either (narrow FOV makes vibration in footage more pronounced).
And as many others mentioned already, this is where GoPro missed the train, their sales are declining while over 1 million drones are being sold in US alone during Xmas period. They should've released GoPro 4 Air version before Xmas with same specs as current GP4, just with a different lens and profile adjusted accordingly, would've cost them almost nothing to implement.
I really want to see what flagship camera they intend to put in Karma and whether GP5 will address this gap in their GP lineup.
