UV filters - slim or not?

[PatrickZ]

About to order UV filters for my two new lenses (17-40 and 70-200). Planning on buying the &W Slim UV MRC for my 17-40.

But do I also need the slim version for my 70-200 f/4 or can I save ~$50 by using the B&W UV MRC?

Thanks!

[sixshot]

I have no idea. Does it make a big difference?

[PatrickZ]

$50 which I don't like to spend if not necessary.

What I need verified is if slim is only required on wide angle lenses

[bolling]

you don't need it on the 70-200

[blue_max]

Logically, it is only an issue if you are looking through the glass from an angle. The thicker the glass, the more distortion a thick piece is going to cause. A telephoto is virtually looking straight through the glass, so the thickness is much less relevant.

That's my logic anyway.

Graham

[J Rabin]

My opinion: You do not require a thin filter on the 17-40L, there is plenty room between front lens element and filter. I also use the B&W MRCs. Highly recommend. In situations where I get flare spots on the 17-40, my experience is I get them with or without any filter. It comes with the WA zoom turf. Because of excellent front element design of 17-40, thin filter is marketing hype.

[mgchan]

I would suggest the thin for the 17-40 and the thick for the 70-200. My understanding for the thin is they are designed to avoid vignetting problems with WA lenses, and not so much for the clearance between the lens and the filter.

[CoolToolGuy]

Logically, it is only an issue if you are looking through the glass from an angle. The thicker the glass, the more distortion a thick piece is going to cause. A telephoto is virtually looking straight through the glass, so the thickness is much less relevant.

That's my logic anyway.

Graham

The 'thin' is usually more about the mounting ring than the glass, and more about vignetting than distortion. ;)

Since they are both EF lenses made for a full frame, normal thickness filters will usually suffice - even if you want to put a polarizer on top of the UV.

Keep in mind, however, that B+W's thin filters do not have a front filter thread, so you lose your Canon clip-on lens cap. B+W supplies a slip-over plastic cap, but I have had them fall off when they warm up (and I don't know where you would find a replacement). The clip-ons can fall off too, but I prefer them unless there is no other alternative. The B+W F-PRO, which is their standard type, is fairly thin, and has a front thread. The thinnest filter available with a front thread is the Hoya Pro-1.

Hope this helps.

Have Fun,

[thomasrhee]

I use the B+W MRC UV (regular one) without any vignetting problems on my 17-40.

[PatrickZ]

Thanks! I've just ordered 2 MRC UV regular filters and saved $$$$

[Goodl]

what is the thread size on a 70-200 F4 and whats a recommended filter for it that's not too expensive. I'm getting one for an xmas pressie off the missus

[Tsmith]

what is the thread size on a 70-200 F4 and whats a recommended filter for it that's not too expensive. I'm getting one for an xmas pressie off the missus

67mm

[focker]

Trying not to stray from the topic but unless your in dusty situations where you need to protect your front lens element, I really think a lens hood is the only option you need on the front of your lens. That will save you some money and usually give you better shots ;).
If you buy all L lenses then usually you can just keep one nice 77mm around and call it good :D