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Filters for Outdoor Photography: Polarizers, ND Filters and ND Grads Revisited


Selecting filters for outdoor photography has always been complicated, especially for photographers just learning how to use filters. In recent years, more companies have gotten into the market and the selection has grown even larger. In addition to that, lenses have changed. Almost everyone that buys a lens beyond a kit lens ends up getting a lens with filter rings at are 72mm or bigger. This means that lots of advice written in the past needs updating. And it also means that my advice for students and others has changed as well over the last few years.

I still recommend three essential filter types:

  • Polarizing filters
  • Split Neutral Density Graduated Filters (ND Grads)
  • Full Neutral Density Filters (ND Filters)

But my advice on the choices have changed slightly. The most confusing choices are:

  • Filter size
  • Filter holder

The next most confusing choice is caused because the good filters are expensive. While you can find inexpensive versions, they usually aren’t up to par. So the next choice is:

  • Which to buy first

Why Use Filters?

Before we get to the confusing choices, lets review what filters are for. I believe that you use filters for two primary reasons:

  1. Transformation: Using filters changes the look of the image, so you can achieve your vision instead of being limited by lens choice, light intensity, reflections or other factors that can be changed with filters.
  2. Overcome sensor limitations: Helps reduce overall dynamic range in a scene to help the image appear closer to what our eyes saw.

I also think that filters help us achieve flow, because they force you to work in the moment instead of shooting for future processing. This helps you stay in and achieve a higher imaginative state.

Here’s an example of transformation (Note: The examples are screenshots from my filter sideshow that I give at my workshops and to photo clubs):

camera filters transform

 

On the left, I took the image with no filters. On the right, I used an ND grad and an ND filter. They transform the look completely.

Here’s an example of overcoming sensor limitation.  This is how our camera sees a scene (left) and how our eyes might see a scene (right).

how our eyes see vs how the camera sees

 

Because our eyes can see 22 to 24 stops of light (a stop of light is double the amount of light of the previous stop), we see significantly more detail in the shadows and highlights. A camera sees at best about 14 stops of light. Filters can reduce the contrast in the scene and allow us to capture a picture that is closer to what our eyes saw.

What Filter Do

filters
My most used filters. Starting left and going clockwise: Kinesis Photo Gear Filter Pouch [Amazon link], Formatt Hitech holder [Amazon link], 77mm wide angle adapter ring, Singh-Ray polarizer, Singh-Ray 5-stop Mor-Slo ND fitler, Singh-Ray 3-stop reverse ND grad, Sigh-Ray 3-stop soft ND grad.
Above I recommended three filter types:

  • Polarizing filters
  • Split Neutral Density Graduated Filters (ND Grads)
  • Full Neutral Density Filters (ND Filters)

Each does something slightly different.

Polarizing filters: Polarizing filters remove reflections from the water or wet or reflective surfaces. These filters also can make the sky more blue. In outdoor photography, some of times you’ll use them are when taking waterfall pictures, macro shots, fall color photos, when you want a bluer sky (although with wide lenses they cause uneven coloration across the sky) or when you want to intensify colors or remove reflections.

Split Neutral Density Graduated Filters (ND Grads): If you have ever taken a sunset photo where the sky is beautiful, but the ground is completely black or where the ground has detail, but the sky is blown out (white with no detail), then you’ve experienced the limitation of your camera’s sensor. ND Grads help overcome this limitation. The filter is rectangular in shape with the top half a gray color and the bottom half clear. You put the gray part over the sky and clear over the ground and the gray part darkens the sky and helps your sensor capture the entire scene. ND Grads are sold in several configurations:

  • Hard
  • Reverse
  • Soft

The configuration tells you what kind of transition there is between the clear side and the gray side. A hard and reverse share the same kind of transition. It’s abrupt. Hard and reverse do much the same thing, so you only need to buy one style. Soft has a gradual transition between clear and gray. You use hard or reverse transitions when the horizon is a solid line, such as over the ocean or a lake. You use the soft when the horizon is jagged. I prefer reverse transitions over hard transitions, because on a reverse the filter goes abruptly from clear to gray but the further away from the transition it goes, the lighter the gray becomes. This helps keep the sky from turning too dark at the top of the photo.

ND Grads are also sold in different intensities. The most common are 1-stop, 2-stops or 3-stops. This just tells you how dark the gray part is. The more stops the filter has, the darker it is.

Full Neutral Density Filters (ND Filters): ND Filters as opposed to ND Grads are completely gray and usually square. They darken a scene so that you can get a longer shutter (or have a wider aperture). They are sold in different stops, which tell you how dark they are. The most popular ones are 5-stop (or 6-stop depending on brand) and the 10-stop. As an example, a 10-stop filter will take a 1/125th of a second exposure to 8 seconds. That can add great blur to the image. My personal favorite is a 5-stop. I use it at sunrise and sunset to get 30 second exposures. The 10-stop filters are really fun though. At sunrise and sunset you can get really long exposures. I’ll often get around 8 minute exposures during that time using a 10-stop ND filter. You can also buy these in 1- to 4-stops, and 15-stops and 20-stops.

Confusion Alert: ND Filters and ND Grads are often confused. Just remember that the ND Grad is split with a dark and clear side and the ND Filter is solid. You use the former to darken the sky (or other bright areas) without affecting the ground (or other parts of the photo). You use the later to slow your shutter speed and cause more blur.

Confusion Alert Two: Some manufacturers use a different type of nomenclature to designate how dark their filters are. I think the ideal way is to tell you how many stops. For example, if you want a 3-stop filter, the manufacturer should say that it’s a 3-stop filter, but some don’t. They’ll say that it’s a 0.3, 0.6 or 0.9 density. That means 1-stop, 2-stops or 3-stops, respectively. If you look at a scale made from this style of nomenclature it goes like this from 1-stop to 10-stops: 0.3, 0.6, 0.9, 1.2, 1.5, 1.8, 2.1, 2.4, 2.7, 3.0. You can also run into the ND nomenclature that goes from 1-stop to 10-stops on this scale: ND2, ND4, ND8, ND16, ND32, ND64, ND128, ND256, ND512, ND1000. I’m including a handy chart.

ND filters to stops conversion chart
So, let’s see what these filters can do with a recent example.

Choices: Filter Size and Filter Holder

singh-ray filters for waterfalls
In the lower right note the polarizer adapter ring screwed into the standard Formatt Hitech filter holder. The polarizer directly above to holder screws into the polarizer adapter ring.

It can get confusing when you have to decide what size to get and which filter holder to buy, especially with the changes in gear and filter thread sizes that have been happening. So, here’s the simple rules of thumb to stick to. If you use:

  • Full frame then buy 4-inch by 6-inch filters. These are also known as 100mm by 150mm or Cokin Z-size.
  • APS-C DSLRs (1.5x or 1.6x cropped cameras) then buy 4-inch by 6-inch filters. Same as full frame users.
  • Mirrorless cameras (except for full frame) usually use 75mm by 120mm. You might be able to get away with 75mm by 90mm, but if you have a wide angle lens, the 120mm option gives you more placement options when shooting vertical. This is often called Cokin P or Lee Seven5 size. Keep in mind that both Cokin P filters and Lee Seven5 filters are only 90mm long. This size will not work well on some lenses.

The filter holder choice is almost as confusing. The key is to pick the brand you like and then buy the size to fit the filter size that you need. Each filter holder has two components and you need both to make it work. It has an adapter ring that attaches to your lens and a filter holder that attaches to the adapter ring. The adapter rings have a couple of options depending on the brand:

  • Wide angle adapters are used for wide angle lenses. They get the filters as close as possible to your lens so you avoid vignetting (darkening of the sides and corners).
  • Size. You need to buy the right size for your lens. Find the filter ring size and buy that one. Common sizes are 40.5mm, 48mm, 52mm, 56mm, 62mm, 68mm, 72mm, 77mm and 82mm. If you have different sized filter rings on different lenses, you will need a different adapter ring for each lens.

There are basically 5 options:

  • Sensei Pro: This is a modular, all-metal holder that rotates on an adapter ring. It has a 86mm ring for a polarizer. To use ND filters, you’ll need to build a light block dam with gaffer’s tape or with foam. This is my preferred filter holder. You can read my full review here: Sensei Pro Filter Holder Review
  • Formatt Hitech: This is an modular, all-metal holder with a simple thumbscrew that holds the holder to the adapter. If you crank the thumb tight, it probably won’t come off. To use a polarizer with this system, you buy a polarizer adapter. It mounts on the outside of the holder and allows you to screw a polarizer on the outside. This is my second favorite system, because it’s dead simple.
  • Lee: This is modular system as well. Instead of a thumbscrew that tightens on the adapter ring, the holder clips onto the ring and freely spins. Force coming from the camera to the back of the holder can cause it to pop off. This is a great holder despite that quirk. To use a polarizer with this system, you buy a polarizer adapter. It mounts on the outside of the holder and allows you to screw a polarizer on the outside.
  • Cokin: An okay filter holder that is a little futzy to use. I’m seen expensive filters fall out of this system easily. They make a special polarizer that drops into a slot on the holder.
  • Vü Filters: A new brand and interesting holder. The polarizer is built into the base of the filter holder. You need to use a special polarizer that is thin enough to work with the holder otherwise you lose the ability to use the first filter slot, which is the one you want to use for you ND Filters. The tolerances are tight on this filter. So tight, that I’ve seen people have difficulty with getting other brands of filters into the holder until they work on the spacers. The attachment to the adapter ring uses two screws that are on the backside of the holder. Seemed more futzy than the Lee or Formatt Hitech holders.

Buying Filters and What Filters to Buy

You don’t want to skimp on filters. There are a lot of brands out there and the prices range from a few bucks for a filter to over $300. The problem with most inexpensive filters is that you will see a color shift. For example, Cokin ND grads and ND filters make your image look purple. Some other cheap filters shift the images color to cyan. Almost all the 10-stop ND filter shift one way or the other, but the best brands show minimal shift that is easily correctable.

Brands: I use and recommend Singh-Ray, and because I love their filters I partnered with them to offer workshop students a 10% discount on their filters. This can be considerable savings for you. If you’re buying an entire kit the discount can pay for half of some of my workshops. Other good brands are Lee and I heard the Vu is good, but I haven’t tried them. Formatt Hitech’s ND Grads are less expensive than Lee or Singh-Ray and are okay. Make sure to get the 4×6 and not 4×5 size if you buy Formatt Hitech, because they sell both sizes.

Buying Recommendations: My recommendations are based on where you plan to do the majority of your photography. I’m going to break my recommendations down into two categories: General Landscape, Seascape. If you live on the flat plains, the seascape kit may work well for you. Both will get you the same filters eventually, but the order in which you buy changes. I’m going to number the filters with number 1 meaning the first that you should buy. You should also get a polarizer regardless.

General Landscape Filter Kit

  1. 3-stop reverse ND grad: This is best for seascapes and lakes or places with flat horizons.
  2. 2-stop soft ND grad: This works well for areas with jagged edges and is easier to learn how to use vs. the 3-stop soft version.
  3. 5-stop or 10-stop ND filter: To achieve long exposures that blurs water or clouds. This is a hard choice. If you’re a seascape photographer shooting mainly at sunrise and sunset, then I’d go with the 5-stop. If you want to blur clouds during midday, I’d go with the 10-stop.
  4. 2-stop reverse ND grad: Great when the air holds high humidity or the colors and sky are muted.
  5. 3-stop soft ND grad: Helpful to have when you face extreme contrast and jagged peaks.
  6. 5-stop or 10-stop ND filter: Buy whichever one you didn’t get last time.

Seascape Filter Kit

  1. 3-stop reverse ND grad: This is best for seascapes and lakes or places with flat horizons.
  2. 2-stop reverse ND grad: Great when the air holds high humidity or the colors and sky are muted.
  3. 5-stop or 10-stop ND filter: To achieve long exposures that blurs water or clouds. This is a hard choice. If you’re a seascape photographer shooting mainly at sunrise and sunset, then I’d go with the 5-stop. If you want to blur clouds during midday, I’d go with the 10-stop.
  4. 2-stop soft ND grad: This works well for areas with jagged edges and is easier to learn how to use vs. the 3-stop version
  5. 3-stop soft ND grad: Helpful to have when you face extreme contrast and jagged peaks.
  6. 5-stop or 10-stop ND filter: Buy whichever one you didn’t get last time.

A few recent examples of photos created with these filters.

Singh-Ray Filters Discount

My workshops students qualify for a discount from Singh-Ray Filters. For details contact me directly or check your participant package.

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