Help buying polarizing filter

[superemone]

I want to buy a polarizing filter but I'm very confused which one to get and the difference between them. I currently own a Canon 40d with 50mm f.18 lens.

Please help me pick out one! Thanks all!

 

[Do'Urden's Eyes]

you probably meant F1.8 lens lol. i own that lens and i know the filter size is 52mm (its printed on front part of the lens). its an auto focus lens and camera so you need a 52mm circular polarizer. though linear might be cheaper it wont work properly with your setup.

 

[Rhubarb]

G'day superemone. Personally for screw in filters I only use Hoya or B+W multi coated filters. One thing to consider is that anything you put between your subject and your lens as the potential to degrade image quality. So if you are using a lovely sharp lens like a 50mm f1.8 ideally you don't won't to be putting a cheap filter in front of it.

Multi coated filters help to reduce flare caused by the filter.

I find that the performance of the top B+W and Hoya filters to be on par, however the B+W mulitcoat is heaps easier to clean, so I lean towards B+W unless the Hoya is a fair bit cheaper (as they often are).

One last thing to mention that a decent quality filter for your 50mm may almost cost as much as the lens itself (the 50mm f1.8 being perhaps the best valued item available in the photography world) and you are unlikely to have many lenses that have a 52mm diameter. One thing to consider is a step up ring, which will allow you to put a larger filter on a smaller diameter lens. An example would be to invest in a 77mm or 72mm filter and use a step up ring so it can be used on any lens with a small diameter. The only trouble you can run into is with the use of lens hoods, which may not fit over the oversized filter.

 

[tirediron]

A couple of points, I'll echo Rhubarb's recommendation for the B+W filters. As he said, you don't want to put something cheap between your lens and the subject. A general rule of thumb is: "If it's glass, buy the best". With respect to the issue of step-up rings, they're good to a point, but don't go crazy. If you have a 52 mm and a 56mm lens, then step-up/adaptor rings will work fine. I would not go from a 52mm to a 72mm however. (a) You won't find one, and (b) it's going to put a big "lip" at the end of your lens which will cause nothing but problems. Finally, I think you will find that you need to stick with C-POL vice L-POL as the linear do not normally work properly with digital.

 

[Josh66]

(a) You won't find one,

http://www.bhphotovideo.com/c/product/22008-REG/Heliopan_700155_52_72_mm_Step_up_Ring.html
They also have a 52-77...

(b) it's going to put a big "lip" at the end of your lens which will cause nothing but problems. Finally, I think you will find that you need to stick with C-POL vice L-POL as the linear do not normally work properly with digital.

Not sure what kind of "problems" the lip is going to cause...it shouldn't obstruct anything. It might look kind of odd, but it should still function normally.

 

[Rhubarb]

With respect to the issue of step-up rings, they're good to a point, but don't go crazy. If you have a 52 mm and a 56mm lens, then step-up/adaptor rings will work fine. I would not go from a 52mm to a 72mm however. (a) You won't find one, and (b) it's going to put a big "lip" at the end of your lens which will cause nothing but problems.

Hi tirediron, I think you make a good point about 'oversized' step up rings but I am curious. I use a step ring for 77 - 72mm, so not a big difference. I haven't used a step up ring for something like a 77 - 52, but before suggesting it I tried to come up with potential problems and couldn't think of any other than that of fitting a lens hood over it.

Would you mind clarifying some of the potential problems? Is there a chance of the optics being degraded or is it more of a hassle in term of mobility with a fat overhang at the end of your lens?

(And you can indeed get these sized step up rings).