which filter to buy?

[redonnemoi]

hi
i bought a canon digital xti plus tamron 28-80mm zoom lens. i need to buy a polarizing filter for it, maybe including a fluorescent plus uv filter too. i have two questions:

whats the difference in effect between a linear polarizing filter and a circular polarizing filter?

which filter should i buy?
thanks

[another view]

You may have seen this thread on filters - even though it's almost four years old it was recently resurrected and the advice really hasn't changed. You really won't need color correcting filters like an FL with digital - learn about White Balance and you'll be all set.

[freygr]

You will need a circular polarizing filter. Some digital cameras do not like the linear polarizing filters. The UV filter but like "another view" said you don't need color correction filter with digital.

On the filter purchase the Polarizing filter for your largest lens and then get setup rings for your other lenses, far cheaper than spending another $50-$200 for another filter.

[redonnemoi]

where does one buy setup rings?
also, i wanna buy an extension tube so that i can let the camera focus on something closer than 27 inches, which is the minimum focal distance of that lens. which extension tube do i need?
thanks

[Frog]

I think almost everyone uses the Kenko extension tubes.
I bought a set of 3 so I have just about any combo I'd ever need.
There's a sticky about extension tubes in Nature & Wildlife.

[brmill26]

freygr meant to say "Stepup" rings. So that may have thrown you off if you were trying a search

B&H has quite a few: http://www.bhphotovideo.com/bnh/cont...arch&Q=*&bhs=t

[another view]

where does one buy setup rings?

They're actually step-up rings, stepping up the diameter of the lens to fit the filter. For example, if you had lenses that had 52mm, 62mm and 72mm filter sizes just buy one 72mm circular polarizer. Then buy a 62-72mm step-up ring and either a 52-72mm or 52-62mm (using the 52-62 with 62-72) so the filter will attach to your other lenses.

Just picking random sizes, and sometimes the right sizes of step-up rings can be hard to find - try a place like B&H Photo. It can be a pain to do this but I rarely use any filters on my 50mm prime lens. I do have a 77mm polarizer and that lens takes a 52mm filter so it does look a little strange, but I do have the right step-up ring and it works. Without the step-up ring, I wouldn't have a polarizer (not worth it to me to buy a separate 52mm diameter polarizer). The problem used to be a lot worse with film, because there would be color correction filters - 81A, 80B, FL as you mentioned, etc, so a lot less filters to buy and carry this way.

Step-down rings are also available, using a smaller filter on a larger lens - but they're usually not going to work well.