CP on UWA lenses

I'm a bit confused on this matter... I've read (and seen) that polarizers on UWA lenses can result in wild banding. But I've also read of people who use them regularly with UWA lenses.

What is your experience?

I rejected the idea of buying the Sigma 8-16 because it doesn't allow for polarizers, but if I can't use a polirizer on any UWA lens, then the 8-16 becomes a feasible option for me.

Any insights are appreciated.

Polarizers on UWA's can cause strange banding effects when you have a lot of open sky in the frame. If you're not shooting the sky, then they just do what they normally do.

It does, in some circumstances, cause irregular effects and/or banding but I sure as hell don't let that keep me from using my CPL on my 10-22. Especially when I'm not shooting skies; they're still useful for removing reflections in water or improving contrast/saturation in colors (especially greens and blues). Heck...every once in a while, the irregular effect can work with the image you're trying to get, too; it's just a trial and error sort of thing. If I slap the CPL in and don't like the results through the VF, then I just pull it back out again <shrug>

Mine stayed attached to my EF-S 10-22mm just about all the time hiking in Glacier NP recently.

I'm one of those that uses them a lot (when appropriate, but that seems to be quite often for me). So much so that I recently spent $700 building a polarizer setup for my TS-E 17mm. Before I got it I was in Yellowstone and using my 17-40 a lot simply because I needed the CPL and the 17-40 with CPL was going to get a better shot than a TS-E without. That really sucked with a TS-E in my bag.

HOWEVER, people are correct when they say you have to be careful with a CP on an UWA, or even on a wide-angle lens (I have a bad example at 32mm on FF). It's easy to overdo it, especially if you have a lot of open sky. However, even in this case, depending on the sun angle it can still help. You do not always have to set polarization to maximum to get a benefit. If the sky is partially cloud covered, it may still be quite useful though.

Also, in portrait orientation the issue is much reduced.

If in doubt I take two (or more) shots and in some situations where I absolutely need it for foliage (for instance), I will take 2 shots and blend, just as I would if the scene DR was too large.

The only lens I'd consider getting that doesn't take a CPL would be a fisheye.

Below are shots at 17mm and 32mm (OK, that's a 'snapshot'), both with just about max polarization. Yes, it did help the sunset shot, the second needed it for the foliage, but I didn't take a second shot for obvious reasons.

This shot didn't work out, but shows what *can* happen when using a CPL on a WA/UWA lens - Note the uneven darkening in the upper, left and bottom, right corners.

10-22 @ 22mm w/ CPL:

IMAGE LINK: http://www.flickr.com/​photos/snydremark/7819​445784/

It's not so much that you can't use a CPL on a wide or ultrawide lens... it's more that you have to watch out for problems, as illustrated above. It's not a problem with either the lens or the filter, just that filter's effect varies depending upon the location of the sun and the lens' angle of view is great enough that it covers a range of that effect. You can even use it to advantage, in some circumstances.

Best thing to do is mount the filter to your lens and then look through the viewfinder and carefully inspect the effect for any given scene where you'd like to try to use it. Sometimes you might find it ideal, other times a problem.

There are other "issues" that can occur when using a polarizer. For example, at high altitutude it's possible to over-polarize the sky, so that it appears nearly black. It looks odd. Also, it's usually not a good idea to use any filter when shooting directly into a sunset, because the filter quite likely will amplify flare in the lens. A CPL is worse than most filters for that, since it has two layers of glass instead of one.

You just have to watch for these things and avoid them when they are a problem.

Like Alan says, you have to watch out for these problems. And it helps if you know how polarization varies across the sky. Go outside and make a 'gun' with your hand. Point the 'barrel' - your index finger - at the sun and rotate your wrist. The 'trigger' - your thumb - will trace the path of maximum polarization, which is a ring at 90º to the direction of the sun.

With the sun at your back, this ring will be appear as a horizontal band in the sky. Its height will depend on the height of the sun. If the sun is directly overhead then the ring will be along the horizon. If it's near sunrise or sunset then the ring will be an arch from north to south. Here's what it looks like with the sun behind me at an intermediate height...

Thanks to all for your responses. The examples were very helpful.

The bottom line I'm hearing is, "Use it on a UWA when the need arises, but be aware of potential problems and avoid them."

So, it seems then that the Sigma 8-16 isn't an option for me as I often use a CPL, or is there some way to attach a CPL to it?

Can you put a 4" filter holder (Lee or Cokin Z-series) on it, and put the polarizer in the holder?

archer1960 wrote in post #14954624
Can you put a 4" filter holder (Lee or Cokin Z-series) on it, and put the polarizer in the holder?

As I understand it the lens needs filter threads for the Lee/Cokin holders. The Sigma has no such threads due to its bulging front element.

Or is it possible to attach the Lee/Cokin holder without using the lens threads?

The cokin (which I have) uses threads, and as far as I know doesn't have a non-threaded adapter. I don't know about the Lee.

I think Lee either makes something that will work or can be easily modified to work without threads, but I doubt either option will be cheap. If you want to use filters, best stick with a flat front element and threads unless you're made of money and are OK with "forcing" something to work all the time.

And, to the original question, UWA's and CPL's work find together with a little care. You can't stand 90 degrees to the sun and crank up full power polarization or you'll end up with images like the ones above, but with a little thought about your composition and polarization strength a polarizer is just as useful on a UWA as it is on other focal lengths.

You can simply hold the Lee or Cokin filters in front of the lens when you take the shot.

On the other hand, 8mm is pretty ridiculously wide. Have you looked at images made with the lens? It's got pretty strong distortion effects... not "fisheye", but quite strong wide angle effects. Any horizon line other than across the center of the image will have a pretty heavy bend to it, for example. Heavy keystoning of buildings. Etc.