When you choose to compute all the imaging parameters, i.e., select 'T & R & S' for the parameter 'Update camP' in the 3D Computation Dialog, you may find the computed S values are different for images even though the pictures are taken using the same focal length. This is usually caused by not having enough number of points marked in images. The more unknown parameters Photo4D has to compute, the more information it needs to do so reliably.
The following tips can help solve this problem:
If all the images are taken with the same focus length, you can estimate the common S by first invoking the 3D computation using a large SR. Then calculate the average value of all the S values in different images. Recompute 3D information by this the average S and 'T & R' only mode.