How to Photograph Waterfalls (Polarizer vs ND)
In this article Teri Campbell very nicely illustrates the difference a CPL and/or ND Filter can make in your waterfall photography.
A CPL (Circular Polarizer) is a valuable tool in any landscape photography, but in my opinion is pretty close to necessary for waterfalls, quickly elevating your images from drab to fab. An ND (Neutral Density) filter is another great tool. I’ll do my best to explain the difference here.
Have you ever worn a pair of polarizing sunglasses? When you look through them, colors are more vibrant, glare is almost non-existent, clouds pop out of the sky. It can also reduce haze and reflections. A Circular Polarizer (CPL) filter has a similar effect. So lets say you’re at a waterfall, there’s light that’s bouncing off the rocks and the water- put that CPL on, adjust it till all that distracting light/glare is gone and boom. Most polarizers will affect your exposure times- much less than a ND, but we’ll get there in a minute- and I’ve found that on a good cloudy/overcast day, the CPL is all I need to get pretty silky water that’s not blown out. This is my personal preference- some prefer to freeze the water with a faster shutter speed- but I love the ethereal quality that a little bit slower shutter speed brings.
Here’s a few examples of Non-CPL vs CPL:
ISO 50, 16mm, f/16, 3.2 sec, NO CPL (no polarizer)
ISO 50, 16mm, f/16, 3.2 sec, with CPL (polarizer)
You can see that the settings here are identical, but look at that rock on the left, is wet and has a distracting glare…the CPL used in the image on the right takes it almost entirely away.
A Neutral Density (ND) is more powerful than a CPL and is like a really dark pair of non-polarized sunglasses. You can buy them to provide a number of different stops, but the Variable ND, which range on average somewhere between 1 and 8 stops depending on which one you buy is probably the most versatile and will save you some bucks by simply purchasing the one. Problems with ND’s are that they can cause color cast (even the “good” ones- See a post of mine titled “ND Filter”- that’s actually a happy story!) but color cast can just as easily ruin your image, so be careful. I’ll provide an image below from the same waterfall, I wanted to slow that swirl down, so I grabbed the ND. In hind sight, I should have also used the polarizer, but stacking a variable ND and CPL is a pain in the arse- each have a “dial” on them, which makes them very difficult to remove from each other, even with filter wrenches…google those, or just go to B&H and buy them, I promise if you use filters long enough, you’ll consider them the best $13 you’ve ever spent. Here’s the same waterfall, with the ND filter…
ISO 100, 17mm, f/22, 10 sec, ND Filter (Neutral Density)
Here, you see that glare on the rock to the right and some up on the cascades feeding the swirl, but the swirl itself is more dramatic at 10 seconds. I could spend a bit more time in post on this, fix the rest of the image which is a bit under-exposed (largely due to the ND) but for this example, I think you can see the effects of the ND, in this case both good and bad! Because ND filters force a slower shutter speed, pay attention to over exposing the actual waterfall (I’ve done it plenty of times!) also note how much the foliage can move in the extended exposure times, easy to ruin that way too (although that’s fixable by exposure blending- but that’s an entirely different post for another time!)
Let’s talk briefly about which filters to buy…cost is always an issue, but with almost any other camera gear, I’ll say spend as much as you can on better quality, Even if it hurts, it’ll keep you from buying it twice, even a third time. Better quality glass isn’t cheap- but IMO, you paid a fortune for that lens, why on earth buy a cheap filter to slap on the front of it and potentially reduce image quality! That’s my rule, and I’d guess there’s dozens of people out there that would argue otherwise, and that’s fine too. I always buy 82mm filters- here again, they cost more, but the long term savings in buying 82’s and corresponding step-down rings for smaller mm lenses is huge. (look on the bottom of your lens, the filter thread or inside the lens cap to see what size filter thread you have and what step rings you’ll need. Not sure where every brand puts that, but that’s where I find it on my Sony’s and Nikons) A set of step-rings on amazon is pretty cheap, or you can invest in better quality like b+w brand. If your filter thread is say 77mm, you need a 77/82 step up ring, 72= 72/82 step up ring, etc, provided you buy the 82mm filter. BE CAREFUL with step up rings and even screw on filters for that matter, as you can get vignetting (dark corners) in your images. They usually aren’t big, but they are distracting and will need a teeny bit of crop to get out- I usually count on this happening and compose my image to allow for it. As for brands of filters, I’d stay away from most (not all) of the cheapies on amazon, and lean more towards Tiffin on the low end and Singh-Ray on the high end. Hoya, Lee, NiSi and Cokin are other good brands to look for. There’s plenty of options out there, buy what you’re comfortable with, or better yet- ask and borrow from a buddy before you buy them.