The circular polariser filter is one of the most useful filters available to landscape photographers and is surprisingly uncomplicated to use, and provides quite a dramatic effect in your images. The two shots below highlight this difference.
When to use a circular polariser filter (CPL)
Out of all my accessories, the CPL is the one I use the most. In fact I generally leave it attached to my lens by default, so for me the question is more about when not to use it! I don’t use it for sunrise and sunset, and of course at night. I don’t use it when a fast shutter speed is critical (eg indoors, hand held in low light etc). I would consider using it in most other situations – macro, wildlife (in bright conditions), seascapes, landscapes, forest photography.
Adjusting your CPL
The circular nature of the filter means adjustment is very simple. I find using the viewfinder (rather than live view) the best way to see the effect the polariser is having. I use live view quite a lot to assist with composition and focus, but using the view finder when adjusting the polariser is a good tip. The effect of the filter is instantly visible, so simply rotate the filters outer ring until you achieve the effect you are after.
Other points to note
* Be wary of “banding”. In particular in wide angle scenes, with lots of blue sky, there can be a noticeably dark patch in the sky where the filter is at its strongest. Used carefully the banding might add a little something to your shot, but in general it is something to be wary of. Sometimes too, the sky can be plenty blue already, and the use of a CPL can almost be too much – or maybe that’s only a concern in Tasmania where our skies are already so stunningly clear and beautiful
* The CPL itself is dark, so it results in a longer exposure. This is usually a desirable effect (eg when shooting waterfalls or rushing water) but it is unhelpful when a fast shutter is required.
* Being a circular filter, you need to purchase a CPL with the same diameter as your lens. Rather than purchasing a CPL for all your lenses, you might like to look at “step up rings”, a cheap alternative which allows a large diameter filter (say 82mm) to be used on another lens with a smaller diameter (say 77mm). As usual, google is your friend, and these accessories should be available at most camera shops.
The CPL is a filter I recommend for everyone getting into landscape photography, and in particular anyone who is joining me on one of my trips. I hope these notes might serve as a useful introduction to the CPL and I look forward to showing you the ins and outs when we head out in the field together!