reguarding filter sizes.

[Tony The Pony]

in another thread i was asking about macro rigs, well i have a 52mm lens, so when it comes to adapters, do you have to get 52mm or do you have to go down one mm?

[Jon]

Get the same size your lens takes. If you want to use the same filter on multiple lenses, size it to fit the biggest one and get step-up rings to fit the smaller ones.

[rhys]

Get the same size your lens takes. If you want to use the same filter on multiple lenses, size it to fit the biggest one and get step-up rings to fit the smaller ones.

The problem there is that you run into the lens hood issue. If you use a gigantic filter you can't put the correct lens hood on.

[SkipD]

in another thread i was asking about macro rigs, well i have a 52mm lens, so when it comes to adapters, do you have to get 52mm or do you have to go down one mm?I believe you are using incorrect terminology but that your intent is being understood because of the context.

When you say that "I have a 52mm lens", most people would understand that you are saying the the focal length of your lens is 52mm. If what you mean to say is that your lens has a 52mm filter thread, that's what you should say.

By the way, for SLR lenses, you will find the filter thread by looking at the front of the lens. You will usually see something like Φ77mm which tells you that the filter thread is 77mm diameter in this case.

The only filter type that I would recommend anybody use a step-up ring for would be a polarizing filter, and then only if you cannot afford polarizing filters for the various lenses you own. My reasoning is that you seldom will be using a polarizing filter when shooting into the sun, and a lens hood is a little less necessary when aiming away from the sun than when aiming in a direction that the sun can impinge on the lens/filter.

When I purchased my lens set for my 20D (my first Canon system), I bought all three lenses with the same 77mm filter thread so that, among other reasons, I could get away with one high quality (and high-priced) polarizing filter for the three. I bought a thin filter with no female threads on the front because one of the lenses is an ultra-wide-angle lens when used on a 35mm film (or "full-frame" DLSR) body.