I am recently flying a P4P, and a little surprised when I was suggested to run again step 1 due to a 98% of mismatching in between the “standard” focal length and the calibrated after processing. How does it happen since the P4P has well known parameters?
Under Calibration/Internal Parameters Optimization make sure All prior is selected. I would also double check my parameters which is under Image Properties Editor.
There are certain cases where the optimization problem can have more than one solution on a mathematical level. Typically, if the ground is flat, the software might have some issues of estimating the depth and so it could end up in the wrong optimized values.
If you tell the software that you trust the initial camera parameters by using All Prior as Selim suggested, the software will select the solution that is closer to these parameters.
Hi Pierangelo and Selim,
The issue was exactly as you commented.
Now it works properly (0,07% difference).
Thanks for your prompt support.
You’re welcome! Glad that it worked!