These are the 2 steps to set the correct Camera field Of View (FOV) for your camera
Step 1 – Set a default Camera field Of View (FOV)
The first step is to set one of these default Camera field Of View (FOV) values for your camera:
| Monocular | Stereoscopic | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Model name | ELP-USBFHD01M-L180 | ELP-USBFHD01M-BL180 | Leorover Fisheye USB Camera with Waterproof case | ELP-USBFHD01M-L170 | SainSmart Wide Angle FOV160° 5-Megapixel Camera Module - for Raspberry Pi | Generic no-fisheye webcam | Generic smartphone/tablet | ASTAR CaliCam® Fisheye Stereo Camera | ASTAR CaliCam® Fisheye Stereo Camera |
| Camera field Of View (FOV) value | 120 or 130 | 120 or 130 | 120 or 130 | 70 | 100 | 0 | 0 | 120 | 90 |
Step 2 – Check the default Camera field Of View (FOV)
The second step is to check the result provided with the default Camera field Of View (FOV) shown in the table above and adjust the Camera field Of View (FOV) accordingly if needed.
To do so:
- Click on the Save Config and Restart button inside the Configuration page.
- Click on the Main tab.
- Click on Start Positioning.
Now you can check if the default Camera field Of View (FOV) value is correct. A Camera field Of View (FOV) value is correct when 2 conditions are met:
- 1st CONDITION – the black arcs inside the video preview do not cover too much of the frame.
- If there are no black arcs in any of the 4 sides then it means that the selected Camera field Of View (FOV) is too low – please increase it of 20° and repeat the test.
- If the black arcs are on all the 4 sides and fill a considerable area of the frame then it means that the selected Camera field Of View (FOV) is too high – lower it of 20° and repeat the test.
- If the black arcs are slightly seen up and down then the selected Camera field Of View (FOV) is correct.
- 2nd CONDITION – the lines/shapes that are straight in the real life are also straight inside the video preview.
Aren’t sure about the Camera field Of View (FOV) value set?
Please send us the image of the video preview and your calibration file and we will let you know right away if the Camera field Of View (FOV) value is correct.
Please send us the image of the video preview and your calibration file and we will let you know right away if the Camera field Of View (FOV) value is correct.
Important note about the “real” FOV of some cameras
There are some cameras for which the output image is cropped when the resolution is set to a value lower than the maximum resolution and thus the FOV is different than the maximum FOV shown in the specifications. In this situations the Camera field Of View (FOV) shown in the table above is not good and needs to be reduced.
There are some cameras for which the output image is cropped when the resolution is set to a value lower than the maximum resolution and thus the FOV is different than the maximum FOV shown in the specifications. In this situations the Camera field Of View (FOV) shown in the table above is not good and needs to be reduced.
Example
The FOV of the ELP-USBFHD01M-L170 camera (when the Camera image width is set to 640 and the Camera image height is set to 480) is NOT 170° (as when the camera is used at 1920 X 1080). So, setting a Camera field Of View (FOV) of 120° makes the image too cropped (and black arcs would cover a big part of the image). This is why the right Camera field Of View (FOV) in a situation like this one is 70°.
The FOV of the ELP-USBFHD01M-L170 camera (when the Camera image width is set to 640 and the Camera image height is set to 480) is NOT 170° (as when the camera is used at 1920 X 1080). So, setting a Camera field Of View (FOV) of 120° makes the image too cropped (and black arcs would cover a big part of the image). This is why the right Camera field Of View (FOV) in a situation like this one is 70°.