I think there is another reason, assuming that I understood the earlier post, and that by focus stacking you mean achieving infinite DOF by stacking multiple exposures, each focused at a different distance. When you focus on a nearby object, the background is out of focus. When you focus on the background, the nearby object is blurred. The problem is that the blurred image of the nearby object is larger than the size of the focused image of the nearby object. Hence it is not possible to obtain a focused image of the background surrounding the nearby object. Therefore it is not possible to create a focused composite image.
As an aside I feel quite annoyed at having downloaded and tested (but not bought) a new focus stacking programme, only to slowly realise that in general focus stacking is impossible. Odd how these people are prepared to charge you a pretty penny for their software, but they do not explain that it can only work for a restricted range of scenes.
As an aside I feel quite annoyed at having downloaded and tested (but not bought) a new focus stacking programme, only to slowly realise that in general focus stacking is impossible. Odd how these people are prepared to charge you a pretty penny for their software, but they do not explain that it can only work for a restricted range of scenes.
You are correct, problems can occur if you lack images between a near and far object, it is important to stop down enough and to include intermediate steps between near and far objects.
Cheers,
Bernard
