An Introduction to Filters in Photography

Filters are an important photographic tool, and there are many different types and brands available. This post will provide a quick overview of the four most common types of filters used with DSLR cameras, including what they are, how they are used, and example photographs taken with them. (All filters shown are the actual filters that I personally use when shooting.)

Filters are pieces of glass that attach to the front of your lens and serve a variety of purposes. Filters can be for protection or for achieving a certain effect or look in your photograph without post-processing.

There are two main systems for filters. Most manufacturers make screw-on filters that attach directly to the front of your lens. When purchasing this style of filter, you need to know the diameter of your lens (indicated with the Ø symbol). While you can attach more than one filter to your lens, you may run into the problem of the edges of your filter showing up in the corners of your image, which is less than desirable. Also, if you have multiple lenses with different diameters, you have to buy separate filters for each one.

The second system for filters is the Cokin series of filters and holders, where you attach a filter holder to the front of your lens and the filters themselves are larger than your lens and generally rectangular. With the Cokin system, you simply buy a different adjustable piece to attach the holder to lenses of different diameters, but you can use the same filters on all your lenses. The Cokin filters generally cost more up-front but are worth it if you need to use them with different lenses or want to use many filters simultaneously.

Personally, I currently use screw-in filters, and well-regarded brands include Hoya and B+W. If you are already further invested in photography, equipment, and lenses, you may want to consider the Cokin series of filters and holders. I am seriously considering making the switch myself when I can next justify the expense. If you are just starting out and only have a few lenses, then you can stick to screw-on filters, but if you know that you want the flexibility of the Cokin system, then it makes sense to invest in their filters from the start.

UV Filters

UV or ultraviolet filters are among the most common photography filters. Many new camera or new lenses come packaged with UV filters. A UV filter is a basic measure of protection for your camera and your lens. A quality UV filter has no negative impacts on your images or image quality, but the UV filter protects the surface of your lens from direct contact with dust, dirt, sand, fingerprints, and all other matter of debris. A UV filter can also protect your lens from breakage due to human error, especially if you drop or bump the front of your lens up against something. Recommended brands for UV filters include B+W and Hoya. Read more about the importance of UV filters in this post on Lens Accessories.

B+W UV Filter

Circular Polarizers

A circular polarizer is a two-piece filter. The near piece screws into the front of your lens, and the far piece is free to rotate. Just like polarizing sunglasses or car windows, a circular polarizer changes which wavelengths of light are visible through the filter. This effect can serve to emphasize the blue in blue skies and cut down or eliminate reflections in water.

Hoya Circular Polarizer

(Polarizer tip: if you have a pair of polarizing sunglasses, spend some time tilting and rotating your head while looking up at the blue sky or down at a polarized wind shield. You will get an immediate sense of the impact of a polarizing filter.) Polarizers also eliminate reflections and glare in water and are commonly used in waterfall photography. (Read more in Yes, Go Chasing Waterfalls.) You can read more about how to use a circular polarizer in the article Improve Your Fall Photography: use a polarizer or check out polarizers here.

Neutral Density Filters

A neutral density filter blocks some amount of light from your lens and sensor. These filters are called "neutral" because they should not have any impact on the color or color cast of your final image. (Inexpensive neutral density filters often leave a blue or purple color cast in your photograph.) Being able to cut down on the amount of light reaching your sensor is useful in many situations when you want a longer shutter speed.

Fotga Variable Neutral Density Fader
(This is one I don't recommend unless you just want a cheap filter to see what the effects look like.)

There are many different varieties of neutral density filters. The one pictured above is a variable neutral density filter. Like a circular polarizer, it has two connected elements that can be rotated. The version of the left shows the minimum amount of light being blocked, while the version of the right shows the maximum amount of light being blocked. This allows you to control how much light is being blocked simply by turning the filter. Tiffin makes a well-regarded variable neutral density filter, but there are many different styles and brands of variable neutral density filters or neutral density faders available.

20-second exposure obtained using a Variable Neutral Density Fader in mid-afternoon 

Most neutral density filters are sold in an individual "strength" and are not adjustable. These tend to be of much higher quality than the variable filters. You can stack filters by screwing more than one on to each other and adjusting the effect that way. This is where the Cokin system really shines, as it is very easy to slot different filters and different strengths in-and-out of the holder, and you can use several ND filters together without risking edges appearing in your image.

Zykkor Split ND Filter
(Again, this is a very cheap version to try out the effects. You can already see the purple color cast to this filter.)

Another type of neutral density filter to consider is the Split Neutral Density. A split ND filter only blocks light from half of the photograph, and you can find both hard split ND filters (a sharp dividing line in the middle) and gradual split ND filters (a more gradual transition, like the one shown above). Split ND filters are used when you have a scene that is much brighter in one half of the image than the other. With circular split ND filters, you spin and adjust the outer ring to level the split, while with the Cokin system of split ND filters, you adjust the filter holder itself.

Sunrise shot with the Zykkor Split ND Filter, which allowed significantly more color and light in the reflection to balance the brightness of the sky.

Split ND filters are commonly used by landscape and travel photographers to shoot sunrise and sunset images, especially with large foregrounds or reflections. In the example above, you can imagine how the sky was much brighter in reality than its reflection in the water. Using the split ND filter allowed me to better balance the two exposures - making the sky darker so that both the sky and the water reflection could shine.

Another example shot with the Zykkor Split ND Filter

For this photograph of the sunflowers, I used the split ND filter again to block out some of the light from the sky. Otherwise, the sky would have appeared much lighter, and the storm clouds would have lost some of their dark and brooding look.

Summary: Filters

There are many different styles, brands, and systems of filters available, and this article has laid out the four most commonly used by photographers. Think about what your current needs are and which filters suit you best. If you do not already have UV filters for your lens, start there. Then, think about what you shoot most. Are you outside where a polarizer would make a big difference? Do you aspire to shoot long, smooth waterfalls or impossibly smooth water shots? Then look into neutral density filters. Do a lot of sunsets or sky photos where a split neutral density filter would make the difference? Worried about the price tag? Consider buying a cheap knock-off ND filter just to try it out. If you are addicted to the look, upgrade. Whatever you choose, spend the time to really get to know your filter and what it can do for you.

How to Master the Heart-Shaped Shadow in Time for Valentines

Heart-shaped shadows are an easy and versatile way to create a memorable Valentines' Day photograph, and you can even print one to use as a homemade Valentines' Day card. This article will lay out the basics behind creating amazing heart-shaped shadows every time.

Supplies for Heart-Shaped Shadows

The supplies for casting and capturing heart-shaped shadows are quite simple: a larger-sized book with a lot of pages (large paperbacks are often more flexible) and a circle to cast the heart-shaped shadow. You can use any circular, see-through object to cast the shadows. Rings are popular choices, for their shape and romantic connotations. You can also use a variety of camera accessories that you might already have lying around. All of the heart-shaped shadows in this article were created with either a single extension tube or colored filters.

Technique and Timing for Heart-Shaped Shadows

The trick behind creating the heart-shaped shadow is shooting near a bright window in the early morning or late afternoon. You want direct light from the sun to create the strongest shadows, and the lower the sun is in the sky, the longer and more prominent the shadow. Right now, if you live in the Northern Hemisphere, a south-facing window is ideal, as the sun is farther south in the sky and casts long shadows during much of the day. Consider also shooting near a glass sliding door or other large window without panes, so you can avoid having window-pane shadows cluttering up your image.

The photograph above shows one possible setup. (You can see I had to use a standard window and try to shoot around the window-pane shadows.) You want to use a large book, opened towards the middle, in order to get an even, symmetrical heart shadow. Here, I was using a Bible opened to the 1 Corinthians 13 verses popular at weddings. Since this is not near the center of the book, you can see that I used a heavy bottle to slightly prop up the pages on the right-hand side to better match the curve of the left-hand side pages.

Secret tip: you may need a little help getting your circle to stay upright in your book. The extension tube I used was wide enough that it could generally stand up and stay by itself without assistance, but the colored filters were much smaller and had a tendency to immediately fall over. I used tiny pieces of a product called Mini-Hold, a wax adhesive created to hold dollhouse furniture and accessories in place without leaving residue. Two tiny dots where the filter touched the book were enough to hold the filter upright and not be visible in the final photograph.

Strategies and Reminders

Spend some time thinking about which book and which pages you might want to use for this type of shot. Depending on your angle and aperture, it may be possible to emphasize certain words or phrases in or around the shadow. (This is particularly easy when using a ring to cast shadows, as the smaller heart draws more attention to fewer words.)

These two shots were both taken using the book The Miraculous Journey of Edward Tulane, which is a heart-warming tale of love, childhood, and the bond between people and stuffed animals. I really liked the idea behind top choice, showing the older couple meeting and welcoming Edward, but I felt like the color picture was a bit overwhelming and competed for attention with the heart. The bottom version still gave a hint of the story, in the blurring words and black and white picture, but the empty space gave more emphasis to the heart. I ended up choosing the second image for printing and creating my own Valentines' Day cards.

Also be sure to consider your point-of-view and aperture. Experiment with different angles of shooting, including straight on and more off-centered. Try getting higher and lower and see how it influences the feel of the final shot. You should also try a few different apertures, both wide and narrow, to see how the different depth of fields (area of the photograph in focus) changes the feel of the final image.

No need to limit yourself to just one shadow, either! Have fun combining multiples and see what kinds of effects you can  create!

Bonus: Book-Heart Valentines' Day Idea

And, since you already have your camera and a large, floppy book out, why not try creating a heart-shaped book too? A large, paperback book works well, as you have lots of pages to work with. The trick here is finding the angle and heart-shape you want and then using a paperclip or small binder clip in the back to hold the heart-shape in place.

Did you try either of these techniques? How did they turn out?  Share a link to your final image or homemade Valentines below.

Want more great ideas?  Follow Boost Your Photography on Pinterest: Boost Your Photography

---

Boost Your Photography: Learn Your DSLR is now available from Amazon. Get the most out of your camera with practical advice about the technical and creative aspects of DSLR photography that will have you taking beautiful pictures right away.

Yes, Go Chasing Waterfalls

Waterfalls are a classic photographic subject, and despite the TLC song, many photographers do spend time off chasing waterfalls. With the right equipment and a little bit of planning, you can make the most out of your waterfall shots.

Equipment for Waterfalls

Many waterfall photographs feature the long, slow, "cotton candy" looking water that can only be achieved by using a long exposure, on the order of full seconds to even minutes. In order to successfully capture this kind of shot, it helps to have a few extra supplies with you. (After each suggestion, I will offer some 'how to cope without' tips in the parentheses.)

1. Tripod. A tripod will hold your camera steady for a longer shutter speed and can help you get angles or views that might be difficult while hand-holding. Read more about How to Maximize your Tripod for advice on using a tripod effectively. (If you do not have a tripod with you, try resting your camera on something steady like the ground, a rock, or a railing.)

This wide view of a waterfall in Mount Rainier was shot by setting the camera down on the bridge.

2. Remote Shutter Release. A remote allows you to trigger your camera's shutter without touching the camera. This minimizes camera shake and helps you capture a steady, sharp image. A remote shutter release also allows you to use the 'Bulb' setting on your camera to get shutter speeds longer than 30 seconds. Read more about why Remote Shutter Releases are a Cheap and Easy Upgrade. (If you do not have a remote with you, use the 2-second or 10-second timer on your camera.)

3. Circular Polarizer. A circular polarizer helps with waterfalls in two ways. First, it reduces the amount of light entering your camera by one or two stops, which allows you to shoot with a slower shutter speed. Second, turning the polarizer allows you to only record light bouncing off the water instead of through it, which maximizes the slow water effect. Read more about how a Circular Polarizer will improve your photography and how best to use one here. (If you do not have a polarizer, you can try shooting through polarized sunglasses, but this can add an unusual color cast to your images.)

Sunglasses can mimic the effect of a polarizer but often add a color cast.

4. Neutral Density Filter. A neutral density filter (regular or variable) allows you to reduce the amount of light entering your camera. A regular neutral density filter will reduce the light by a set amount of stops, while a variable neutral density filter will allow you to vary the amount of stops. The darker the filter, the less light that reaches your camera, and the longer you can leave the shutter open. (If you do not have a neutral density filter, you will not be able to get the really long, slow shutter speeds.)

Making the Most of Your Waterfall Shots

Shoot in Aperture Priority or Manual Mode

When shooting waterfalls and trying to get the long, slow water look, you want to get the slowest shutter speed you can while still keeping the overall shot exposed properly. To do this, you want to set your ISO to 100 (or the lowest value on your camera) and your aperture to f/22 (or higher if you have it). If you are shooting in aperture priority mode, the camera will then calculate the longest shutter speed that it can for the given ISO and aperture. If the picture comes out too light or too dark, switch over to manual, dial in the same settings, and adjust the shutter speed as needed.

If you are able to use a shutter speed longer than 30-seconds (likely if you are using a circular polarizer in combination with a neutral density filter), then you will need to use the 'Bulb' setting in manual mode. In Bulb, the camera will leave the shutter open as long as you press the shutter button or hold down the remote. Using a remote with a lock allows you to keep the shutter open as long as needed to get the shot.

Gorge of Waterfalls by Archaeofrog. Available for purchase.

Aim for Even Lighting

Waterfalls look best when they are shot under even lighting: either the entire scene is in direct sun or in the shade. Dappled light can be very pretty in real life but makes it difficult to properly expose for your waterfall shot. In the shot below, you can see that the parts of the falls in direct sunlight are too bright, while the shady sections are still dark. Cloudy, overcast, or just entirely shaded falls work best, as the lighting is already a little lower, and you can use a longer shutter speed.

The bright sunlight spots make this waterfall image uneven.

Provide a Sense of Scale

Waterfalls vary greatly in size from small ripples through stones to powerful behemoths with thousands of gallons of water pouring over each minute. Think about providing your viewer with a sense of scale or context when composing your waterfall shot.

Waterfall at Mendenhall Glacier

This composition emphasizes the power and scale of this waterfall in Juneau, Alaska. The falls itself fills the entire frame, and alone, the viewer would have no idea as to the scale of the falling water. The addition of the couple, however, provides that needed sense of scale, and lets the viewer understand some of the immensity of this waterfall.

Vary your Perspective

Many people look at waterfalls, take a shot of then head on from the bottom of the falls or an overlook, and move on. This can be a very lovely shot, but there is so much more than you can do.

Waterfall in Fall by Archaeofrog. Available for purchase.

The photograph above is a more traditional view of a waterfall. While it looks like this was shot head-on from the bottom of the falls, it was actually shot quite a distance away with a zoom lens. This was the middle of a series of falls in a narrow canyon, but zooming in places you, as the viewer, much closer to the falls than is actually possible for that location.

Leaves in the Falls by Archaeofrog. Available for purchase.

Get up close and personal with your waterfall! While not advised for all falls (know your limits), getting physically very close to a waterfall can provide some amazing shooting opportunities. This small waterfall happened to be right next to a fairly dry bank that allowed me to get right up to it with my tripod without actually having to wade through the stream.

Above the Falls by Archaeofrog. Available for purchase.

Looking down from above is another way to change your perspective and get a different waterfall shot. In this one, the focus is much more on the swirling leaves in the background than on the actual waterfall itself. Again, a long shutter speed (60 seconds in this case) made the swirling pattern evident.

Forget the Waterfall Entirely

Both of these next shots are untraditional versions of waterfalls shots: the falls itself is not even visible.

Serene Swirls by Archaeofrog. Available for purchase.

In this shot, the focus is on the swirling leaves and the narrow gorge that is the setting for the waterfall. This image was a combination of two shots, one for 15 seconds to expose for the swirling leaves and water, and one for 5 seconds to expose for the brightly lit background.

A Wide Look at Fall by Archaeofrog. Available for purchase.

This shot is off the water just above the waterfall. Here, the water is still and its mirror-like surface reflects the scene around it. This reflection is only slightly disturbed by the ripples as the water approaches the falls. The leaves in the foreground bring a wide-angle feel to this image. The key to shooting a photograph like this one is to get the camera physically down low to the water and to shoot with a wide-angle lens (although 18 mm was the widest that I had here).

Waterfall Summary

If you want to shoot waterfalls and want to achieve the long, slow moving water style, then it helps to be prepared. Bring along a tripod, remote, circular polarizer, and neutral density filter, so that you can get longer shutter speeds, such as 15 or 30 seconds or even up to full minutes. Think about the lighting and try to plan your visit for a time when the waterfall and surrounding scene will be in full shade (or full clouds or overcast). Once you are there, do not be satisfied with just getting the 'classic' waterfall shot. Take some time to vary your perspective and include a sense of scale. Consider even forgetting about the waterfall entirely for some shots. You may be surprised to find that your favorite shots are those where you took the time to try something new.

Waterfall in Motion by Archaeofrog. Available for purchase.

Want more great ideas? Follow Boost Your Photography on Pinterest: Boost Your Photography

Improve your Fall Photography: use a polarizer

October is here, and the dropping temperatures have raised my excitement for excellent fall photography opportunities. Autumn is my favorite photographic season, and this post will focus in on one quick photography tool that will rapidly improve your autumn images: the circular polarizer.

Autumn Walk by Archaeofrog on Flickr, captured with a circular polarizer

A circular polarizer is a filter that attaches to the front of your lens. Rotating the filter changes which wavelengths of light are visible through the filter. This effect can serve to emphasize the blue in blue skies and cut down or eliminate reflections in water. A polarizer can really make the colors of fall leaves pop and brighten up a bright blue background for them too.

Circular Polarizer Comparison by Archaeofrog on Flickr

These two images demonstrate how a polarizing filter can improve an image. The image on the left was shot at f/5, 1/50th of a second, while the image on the left was shot at f/4.5, 1/40th of a second. Both images were taken with the polarizing filter attached to the camera, but the filter was rotated in between images to first minimize and then maximize the polarizing effect. The impact of the circular polarizer can be seen most clearly in the brightening of the sky and in the increased saturation of the colors in the right-hand image.

Example of a circular polarizer. The shadow is created by the light-blocking effect of the polarizer.

Tips for Using a Circular Polarizer

First off, a circular polarizer has two elements. The back of the filter contains the threads that allow you to screw it on and attach it to the front of your lens. The front of the filter rotates freely around, allowing you to align and adjust the filter for the look you want. (Some filters, like the Cokin series, have a special holder that then attaches to the lens, but using and rotating the filter works in the same way as described below.) If you use a UV filter on your lens at all times for protection (and you should), then you need to remove the UV filter before attaching the circular polarizer, otherwise you may have an unwanted vignette effect where the circular edges of the polarizer may become visible in the corners of your images, as in the image below.

I screwed multiple filters onto the front of my lens when taking this image. As a result, the edges of the filters are visible, created an unwanted vignette effect.

Here’s what no book ever came out and told me about circular polarizers: there is no 'correct' way to align a polarizer. The first several times I went out and used my first polarizer, I was continually frustrated because I could not find any markings to indicate a 'maximum' or 'minimum' polarizing alignment. I would look through the viewfinder, spin the polarizer around, and see nothing happening. I would try taking a picture, rotating the polarizer 90 degrees, take another picture, rotate, etc. and notice no apparent differences between the images. I finally went so far as to mark the 'top' of the filter edge with white out, so that I could at least see where I was adjusting it to and from.

I thought I was crazy. I had been reading all about photographers raving about their polarizers, and nothing happened that I could see when I was using it … until I happened to aim at some windows.

Changing window visibility with a circular polarizer

The windows of the Red Cross building finally showed me the impact of what the polarizer could do. At one alignment (left), I could see the light shining through the windows and into the rooms within, but when I began to rotate the polarizer (right), I could see the windows become opaque and then nearly completely solid. At the time, I did not notice the changing blue hues in the sky, but they were more obvious to me when viewing the photographs on my computer.

This changing visibility through the windows is the same effect that polarizers have when you are using them to shoot water. At one alignment, the polarizer will be letting in the light going through the water and show you what is underneath, while at another alignment, you will only see the light bouncing off the water and not be able to see underneath. Photographers exploit this tendency of polarizers when shooting water to minimize the glare or reflections of bouncing light in the image.

After further experimentation and reading, I finally understood that a polarizer works best in specific situations. To start, a polarizing filter really works when the sun is at a 90 degree angle to your subject (as in, the sun should be shining off to one of your shoulders). The effect is greatly diminished if you are facing directly towards or away from the sun or if the sun is directly overhead. Depending on the relative angle of the sun and your subject, you may find that the polarizer creates more of a gradient than an even color tone across the sky.

Incorrect use of a polarizer can result in a drastic change in color and darkness across the sky.

Once you have found a scene that will utilize the effects of the polarizer, you should be able to see the changes happening as you rotate the filter. The blue of the sky is a good place to watch. As you rotate, you will notice subtle changes in the blue from a deeper, darker color to a softer, lighter color and back. It is those deep, dark blues that make the circular polarizer popular, but you may choose an in-between version, if it better fits your vision. This is where there is no 'correct' answer. The exact angle at which you align the polarizer for the effect you want depends on many factors including the angle of the sun in the sky, the angle of the sun relative to the camera, and the angles at which light is bouncing off your subject and into your camera. So there is no automatic 'maximum polarization' setting. If someone had only told me that upfront, I would have felt far less foolish …

Another thing to keep in mind is that the using a polarizer will also change the settings that you need to use for that particular situation. A polarizer, by definition, blocks out certain types of light, so when using a polarizer, you will need to use a wider aperture or a longer shutter speed to accommodate for that loss of light and ensure a properly exposed image.

Comparison of the impact of a circular polarizer on the sky and autumn leaves.

As an example, if you first composed a scene using aperture priority set at f/8 (for a reasonable depth of field but still a quick shutter), then the camera might suggest a shutter speed of 1/100th of a second. If you then attached a circular polarizer to your lens and spun it to maximize the polarizing effect, then your camera, still set for f/8, might now suggest a shutter speed of 1/50 of a second. (For the technical minded, this is known as "one stop" of light. A stop is measured for each doubling or halving of a shutter speed value. Most polarizing filters result in a loss of one to two stops of light.) You may want to consider bringing along a tripod to use in combination with your polarizer, so that you can ensure a steady image if you use a longer shutter speed. (Read more about how to Maximize your Tripod here.)

A final tip for successfully using a circular polarizer: always rotate the front of the polarizer the same direction you used to screw it on to your lens. When looking at your lens front-end on, the circular polarizer screws on in the clockwise direction. So, when you are rotating the front part of the polarizer to adjust it, I suggest that you keep rotating it in that same clockwise direction. That way you avoid the potential accident of unscrewing the filter by rotating the whole thing instead of just the outer half. Much less likely to lose or drop or break a polarizer that way.

Purchasing a Polarizer

There are two types of circular polarizers available for DSLR cameras. The first type is more traditional and is a single filter you buy that screws on to the front of your lens. You will need to buy a polarizer that fits the dimensions (diameter) of your lens. If you want to use your polarizer on more than one lens, and your lenses have different diameters, then you will need to either buy a different polarizer for each lens or buy a polarizer for the largest lens and then buy step-down adapters to use the larger polarizer on the smaller diameter lens. As an example, my Tamron 18-270 mm lens has a diameter of 62 mm, so I purchased a 62 mm Hoya circular polarizing filter for it. When I want to then use that filter on my Canon 18-55 mm kit lens, which has a diameter of 58 mm, I have to also use a 62-to-58 mm step-down adapter to attach the polarizer to the lens. The more lenses you have, the more complicated this can become.

The second type of circular polarizer is sold as part of the Cokin filter system. With Cokin filters, you buy a relatively inexpensive filter holder and then individual adapters that fit the diameters of your lenses, and this holder allows you to use the same filters (including circular polarizers) on all of your lenses. The investment in the filters is often more than buying them individually, but you are not limited in which lenses you can use them with. Cokin filter systems are also popular with photographers who use multiple filters (such a neutral density or graduate neutral density filters) in addition to a circular polarizer, as the filter holder allows you to more easily use multiple filters at the same time. The larger size of these filters eliminates the vignetting problem common when stacking circular filters.

If you are just starting out with photography and with filters, you may choose to purchase a single circular polarizing filter, which is what I did initially. Well-regarded brands for filters include Hoya and B+W. If you are further invested in photography, equipment, and lenses, you may want to consider the Cokin series of filters and holders. I am seriously considering making the switch myself when I can next justify the expense. Whichever you choose, you will soon find that a circular polarizer is an invaluable tool in helping improve your autumn (and really, all season) photographs.

Autumn Light through the Trees by Archaeofrog on Flickr, captured with a circular polarizer

Want more great ideas? Follow Boost Your Photography on Pinterest: Boost Your Photography