Question about buying a larger CPL filter!

[milosh]

Hi folks, I have a question for those of you with more experience.

So, I now own a Nikon 18-105 mm (67 mm filter thread) which I use for almost all of my landscapes, and I plan to buy a Sigma 10-20 mm in the future (77 mm filter thread), and I would like to buy a Hoya CPL, so my question is:

would it be smart to buy a 77 mm CPL (although I don't have the Sigma yet) and use a step down ring for my Nikon 18-105 mm? My only idea is saving money.
I guess the 10 mm difference wouldn't be such a problem (5 mm on each side), and I would have a CPL when I get the Sigma.
Is there any drawback to using a larger filter and step down ring, other than added size?
I'm looking at a Hoya Pro1 CPL for 65$.

Thanks

[Digidave]

That's not a bad idea at all. The only problem you may run into is using a lens hood at the same time. A CPL is best used at 90 degrees from the sun so a lens hood is not a necessity at that point. When you want to turn more toward the sun though you will want a lens hood on & then you will have to take the CPL off.

That's about the only problem I've had anyways.

[OsmosisStudios]

Originally Posted by Digidave

That's not a bad idea at all. The only problem you may run into is using a lens hood at the same time. A CPL is best used at 90 degrees from the sun so a lens hood is not a necessity at that point. When you want to turn more toward the sun though you will want a lens hood on & then you will have to take the CPL off.

That's about the only problem I've had anyways.

It's also very difficult to actually turn the CPL with a hood on.

I usually advocate getting all filters in 77mm size for exactly this reason. a step UP ring (which is what you'll need) is cheap and means that all your lenses can use all your filters.

[Digidave]

It's also very difficult to actually turn the CPL with a hood on.

Well yeah, that too.

[dcclark]

I would also recommend a step UP ring -- a ring for the 67mm lens, to allow it to fit a 77mm filter. Then just buy all 77mm filters -- a nice standard size.

Also, with the 10-20mm lens, any stepping DOWN will definitely encroach on the visible area of yoru images -- it'll give you small black curves in the corners.

But finally, I doubt that you really need a CPL for your 10-20mm lens. Ultrawides look AWFUL with polarizers, because they are so wide that different parts of the image will be polarized differently. Think of a sky with big bands of dark and light blue running vertically through them -- not very nice!

[milosh]

Thanks guys! I guess I'll be checking out 77 mm CPLs and a step up ring. Yeah, I realised that the ring I'll need is the step UP ring.