I currently have a set of 77mm Tiffen filters. In order to use these 77mm filters on my 52mm lenses, I suppose step up rings have to be used. Just to ask. What is the Max number of step up rings that I can use to step up? I was told by Alex Photo at Peninsula that I can step up only if I use 4 rings. I'm kind of worried about using that many rings. Anyone knows if there's actually a 52-77mm step ring available out there? Will the use of 4 rings cause vignetting on my 28mm lens? I once had quite bad vignetting from the use of a non-proper hood. Not sure if using that number of rings has the same effect.