Attention! Before that spews the first negative reviews due to ignorance; o)
The outer ring with the filter can be rotated after you have turned it firmly on the lens!
This only results in the effect!
I have to add a photo at the customer images (railway models behind glass) where you can see the effect is very good. Only a half turn makes it clear how starkly the difference between reflective glass and clear background may be.
Still a bit of tact is attached! By changing the focus, is logically the filter rotates. Since it might need some exercise to start, anyway you get the hang of; o)
I use the filter for models behind glass on a "Canon EFS 18-55mm" lens with 58mm threads on the Canon EOS 1100D.
