From Help:
How to Take Photographs
Creating 3D models using photographs is fun and easy, but if you want to make a high quality output …
General Rules
A few tips …
- Use the highest resolution possible.
- Each point in the scene surface should be clearly visible in at least two high quality images. The more - the better rule applies here.
- Always move when taking photos. Standing at one point produces just a panorama and it does not contribute to a 3D model creation. But move around the object in a circular way.
- Do not change a view point more than 30 degrees.
- Coarse-to-fine rule: Start with taking pictures of the whole object, move around it and then focus on details. Beware of jumping too close at once, make it gradual.
- Complete loops. For objects like statues, buildings and other you should always move around and end up in the place where you started.
I’d think that’s a general recommendation, no mention of circling.
It must be increasingly hard for the algorithm to recognise ‘same thing-ness’ in adjacent photos if their view angle changes a lot.
Even though the wider the convergence angle the less error-prone the projection/REprojection round-trip. But not by a lot, in the proportion 1/sin30 = 2 to say 1/sin 45 = 1.41.
For that latter reason, also small convergence angles become exponentially error-prone, in the proportion 1/sin30 = 2 to say 1/sin10 = 5.76, or even worse 1/sin5 = 11.5 - dramatic!
I guess the sweet spot must lie between 10o and 30o.