Position of the lens's focal point for ZEDX2.2mm

Hardware
1

I am writing to ask about the ZED X 2.2mm model lens.
Could you please inform me about the position of the lens’s focal point in relation to the camera lens surface? Specifically, I am interested in knowing how many millimeters inside the lens surface the focal point is located.

Thank you in advance for your assistance.

2

Hi @Motoki
Welcome to the Stereolabs community.

The camera sensor is placed 20 mm behind the front surface.

3

Hi @Myzhar
Thank you so much! That helps a lot!!

4

Hi @Myzhar
Is the distance from the front surface to the sensor surface 20mm?
I’m working on 3D modeling and examining the angle of view. The vertical field of view is set at 80° for ZED X2.2mm, but something doesn’t add up,

5

Yes, that’s correct.

Did you download the 3D model from our support page?

1 Like
6

Hi everyone,
I am setting up one ZED X camera in simulation, and I think I have the same question @Motoki asked. The answer is not yet clear to me, so I will try to ask the question again, with more details.

My goal is to set up the camera in simulation. For doing so, I need to know where the center of projection of the camera is, with respect to the camera body.

The center of projection is going to lie on the optical axis of the camera, so there is only one DOF to be defined.

I had a look at the CAD model of the camera, and It seems to me that the plane of the image sensor lies at ~23 mm from the front face of the camera. This is similar to what @Myzhar wrote.
If the camera were an ideal pin hole, the center of projection would lie at the distance of one focal length from of the image sensor, in the forward direction. So the distance of the projection center from the front face of the camera would be 23 mm - 2.2 mm = 20.8 mm (or 20 mm - 2.2 mm = 17.8 mm, according to the value provided by Myzhar).
But I guess the lens of this camera is much more complex than a pin hole, so it might not be modeled correctly by that.

The CAD model also features an object that represents the Field of View of the camera. The origin of the Field of View lies ~7.6 mm behind the front face of the camera. This value is quite different from the ones computed earlier…
Can someone tell me what the correct location of the projection center is?

Thank you in advance.