For any outcrop, in order to recreate it in 3D, first you have to choose the level of detail that you would like for it. That level of detail will dictate the distance from which you will take the photos. In the above example the greatest detail for the outcrop is achieved from the third point of view. However, in order to have an accurate, easy and fast 3D reconstruction process, all points of view (i.e. first, second) that lead to the closest point of view (i.e. third) are needed. So the easiest way to do this is to begin with the farthest point of view and to gradually get closer.

The next step is to take overlapped photos of the entire outcrop. The best overlapping is achieved at a 10 degree step, but it is quite hard to accurately measure degrees in the field without a lot of work and calculations. So the best and easiest way to take photos is by walking sideways and take one picture at each step.

Furthermore as you get closer to the outcrop you should also take vertically overlapping photos as shown in the "Side view" examples below.

To summarize:

Take overlapping photos at the maximum distance from the outcrop and after you completed the whole outcrop at that distance, gradually go closer and take another series of pictures.

From the farthest point of view you should encompass the whole outcrop vertically.

From a closer point of view it is possible that you would need to take two overlapping photos to be able to encompass the whole outcrop vertically.

Getting even closer you would need three or even more photos to encompass the entire outcrop vertically.

Dumitriu, T. C., 2013. Towards digital preservation of Repedea's big quarry outcrop using "Structure-from-Motion" photogrammetry tools. Analele Științifice ale Universității "Al. I. Cuza" din Iași. Seria Geologie. Tome. 59 (2), pag. 19-40.

In depth Youtube tutorial from The arck project.