For terrestrial projects such as 3D reconstruction of a church, statue, interior rooms, walls etc., the lighting conditions can create problems. The object can be overexposed or usually underexposed. This can lead to bad images (too much light or with shadows), which in turn leads to poor reconstruction.
One possibility to alleviate this problem is to use HDR images. Pix4Dmapper can process HDR images. HDR is the abbreviation for “High Dynamic Range.” It is a technique that merges multiple images of different exposures to produce an image with minimal blowout and black crush: http://www.canon-asia.com/snapshot/eos-5dmk3-hdr-170/.
One situation which can be particularly tricky is with artificial light that needs to be moved to illuminate different sections of the project, i.e. the light changes between different sections. In this case, it will be necessary to merge the projects associated to the different sections. Ensuring sufficient overlap between the different sections and taking the change in shadow location into account can significantly reduce the time needed to merge the projects since it will make it easier to add Manual Tie Points common to several sections.