All lenses produce focus on a hemispherical plane, not a flat plane like a sensor or film is, and with wide-angles this is pronounced
Dear Halftone, what you are explaining here, is fairly obvious. But I am afraid that you are missing my point.
Every lens has something what I call "a circle of acceptably good focus", as perceived by user. It is not a scientific term, but a practicability-oriented one I just invented just for the sake of better explaining my point. Of course this circle does not have exactly defined limits (they are gradient), and its actual size also varies depending on lighting conditions, current aperture and shutter speed etc., but let me skip such commonplaces. Important is, that within this circle a lens is able to provide enough picture detalization for a typical user not to get the feeling that his picture is missing mission-critical details. For dashcams such details are license plates.
If under _most_ design conditions (or call them typical usage scenarios, whatever) of a specific digital imaging device its lens provides an acceptably good focus circle with a radius, which is _longer_, than the length of the rectangular image sensor diagonal of the same device, we can talk about such lens being properly selected by manufacturer to suit the specific device type.
If, on the contrary, under many device usage conditions the radius of such a circle is less, than the sensor diagonal (in other words, if in real life this circle too often turns smaller, than the rectangular image sensor, not covering the whole sensor area), we can talk about such lens being IMproperly selected by manufacturer to suit the specific device type.
Maybe for top photo cameras you professional photographers use the price difference between such two lenses would mean 10+ K$ - I do not know.
What I am perfectly sure of, is that in the dashcam world we are in, with tiny sensors and lenses, the difference mostly depends on proper lens selection, rather than price. I used to have a similar price range DOD dashcam before (P.S. two of them, actually), which had tons of other problems (reliability etc.), however their images were crisp from edge to edge. BTW neither did the DOD have any pronounced temperature-related focus drift problems. Based on this, I make the conclusion, that with proper lens selection (P.S. and with proper lens holder material selection, to avoid the temperature-related focus drift) my both Viofos would have been able of rendering videos not less crisp, than my old DODs - videos I would have no complaints with in terms of sharpness. And it is not inevitable that my Viofos have these problems, since other dashcam do not, despite the laws of physics and optics being the same for them all: it is a Viofo design flaw.
