Field of view?

[Nigel]

In other words they are LESS THAN 90 degrees to the lens each, which is LESS THAN 180 degrees total. 180 degrees horizontal is a line connecting two points directly beside the cam left and right, with the lens of the cam being on that line between those points.

I never thought I'd have to explain 6th grade geometry here.

Phil

I think there is some confusion about which direction is forwards, my camera is facing the front of the car, but the cabin image is facing the rear - that is what happens with dual lens cameras!

I still say that with a rear facing image, if the field of view was less than 180 degrees and the door mirrors were visible then you would see the plastic side of the door mirrors, while in my image above I see the plastic side of the rear view mirror but the reflective side of the door mirrors - the door mirrors are behind the view at around 200-210 degrees (100-105 degrees from the centre of the image).

 

[TonyM]

@Nigel can you hold a straight stick up to the cabin camera, perpendicular to the lens axis? If it can see both ends of the stick it has at least 180deg FOV.

 

[Nigel]

@Nigel can you hold a straight stick up to the cabin camera, perpendicular to the lens axis? If it can see both ends of the stick it has at least 180deg FOV.

If I stuck a straight stick directly below the camera, running straight across the car, there would be a bit of a problem due to the curvature of the glass and the fact that you would not see the centre of the stick, only the ends, but if I removed the glass so that it was possible to use a long enough stick to see the ends, then in the above image the top of the steering wheel would be directly below the stick - 180 degrees takes us to the steering wheel, everything beyond the steering wheel, including the door mirrors is behind the stick (further towards the front of the car than the camera, or in front of the camera since this is the camera rear view!).

 

[SawMaster]

And if your lens isn't horizontal but pointed downward, anything below and to the sides of the lens will make it appear to have a wider FOV angle than it does. Honestly, I'm tired of this conversation with someone who would rather argue than perform simple tests which would prove my point that most people tend to overestimate FOV angles, Maybe his next cam will be able to see through the PC board and case too...

Phil

 

[TonyM]

So, taking a typical Porsche 911 Turbo I have drawn on the 140° FOV of a front-facing dashcam, which just picks up the bottom of the A-pillars.

I have also drawn on Nigel's cabin camera with a rear-facing 210° FOV that can see the side mirrors.

 

[Nigel]

So, taking a typical Porsche 911 Turbo I have drawn on the 140° FOV of a front-facing dashcam, which just picks up the bottom of the A-pillars.

I have also drawn on Nigel's cabin camera with a rear-facing 210° FOV that can see the side mirrors.

View attachment 44735

Excellent diagram

I think you have the red box where my mirror is , the camera is a little towards the front, resulting in the full door mirrors being within the red lines.
Maybe my front view is only 135 degrees.

Pretty accurate though, other than the car type

 

[Nigel]

Maybe his next cam will be able to see through the PC board and case too...