I have a camera and I am focusing it at 10 cm distance at the time of calibration using checkerboard and open cv. Some time after calibration I am changing the focus to 100 cm and taking some photos and then again I am focusing at 10 cm, but this time I am using calibration results we generated in starting. Are those calibration results invalid because I have changed the focus in between? Or is it valid, as I am focusing at the same distance where I have calibrated the camera?
The reason to ask this question is, at long distance/far objects focus do not changes to much but my application of camera lies to work between 100 cm to 10 cm where I need to change focus continuously. Are there any options are available for it?
My Idea: Calibrate camera at 2 different mainly important distances (40 cm and 10 cm), and use different set of calibration parameters at both the distances where accuracy is required. Will it work?
I have tried calibrating the camera in auto focus mode but people are talking that it's invalid as calibration parameters changes drastically at different focus points and can not be combined using different images with different focus distance.