Originally posted by ChrisA This effect may be real, it may not, and my inclination is to believe that it is ... but unless
- the camera is on a tripod, so
- the camera is not moved
- and nothing is changed except unscrewing the filter,
... these 'tests' prove little.
None of the pairs of photos exhibiting this effect are actually framed the same.
In fact, they do prove that the use of filters, under "dark with bright spots" situation, produces ghosts of such bright spots. With the use of a tripod, such conditions will not change. Of course, the "slight" angle difference between shots (by not using tripod) will make no difference.
If my tests were focused on "where in the picture" or "at which angle in relation to the bright spot" the ghosting happens, of course, I would use a tripod.
Basically, the test as done, proves the only claimed point: Filters do create ghosts under such conditions.
Next test in a logical sequence, it would be to test different filter brands (coatings) to find out if such coatings do work.
RB