I use one a lot. I just look thru the filter when it is off the camera until I see what I want, note some mark or letter's position on the filter so that I can insure is in the same position when I put the filter on the lense. There are adapter that affectively do this same thing for some rangefinder camera, (some swing the filter over the viewfinder) and then swing it back over the lense when shooting without rotating it. Like I described though, I subscribe to the more manual process.