The size the dots on the calibration template

[Rina_Rena]

Hello. I ask for the help of specialists.
I need to calibrate the camera. Image size 1920 × 1200 pixels. The size of the visible area is 1287 × 810 mm. To minimize distortion, I need to use an A1 size template (594 x 841 mm). Can you please tell me what size the dots should be on a template of this size? Maybe there is a formula to calculate the size of the points depending on the size of the template?

This is a snapshot of an existing template. However, it was noted that the size of the points should be larger.

[another_novice · Accepted solution]

I don't believe there is a formula for dot size. Working from memory here, I think when you learn a calibration you will tell the system the size and pitch of the dots you are using. What I've used is a 5:1 pitch to dot size ratio, so if there is 10mm between dot centers the dots should be 2mm diameter.

Another aspect to consider, especially since you have a large field of view, is that the dots must be several pixels in diameter - like at least 5 and probably around 10.

Last, the smaller your dot pitch, the more dots you will have. That's going to increase calibration accuracy but will give you a larger image and longer processing time.