Filters have been around in photography for years. It used to be the only way to modify the color balance was to use a filter. For example, photography at high altitudes will require an 81A, 81B, 81C or even 81EF depending on the altitude. Taking pictures under incandescent illumination? You will need an 80A or 80B filter to correct the reddish-orange color balance.
Digital Photography has changed all of that with the advent of AWB, auto white balance. Many of these color balance issues are corrected automatically by the camera. While no automatic system is perfect, AWB offers dramatic improvement with minimal involvement. To go further than what AWB offers, you have some options. You can either choose any of the preset options available on your camera or you can use a device to accurately corrects the white balance. At Keeble & Shuchat we carry the ExpoDisk, Lastolite™ EzyBalance or even a good old gray card. All these devices offer you a means to correct the white balance more accurately than most cameras AWB system can.
But I digress from my discussion on filters. Today’s digital photographer uses a much smaller arsenal of filters in their camera bag then the film photographer. I am going to discuss my favorite filters.
Circular Polarizer. These are a favorite of film and digital photographers alike. Circular Polarizers have a ring you twist to achieve the effect. They can darken blue skies, make green leaves more vibrant and remove reflections from non-metallic objects. Every photographer should have one of these in their camera bag.
Graduated Neutral Density Filter. Galen Rowell made these filters popular and the concept is simple. Many times you try to capture a scene only to have the beautiful blue sky come out white. This is because the dynamic range of the light (the difference between light and dark) is too great for the camera to capture. By using a graduated neutral density filter over the bright area you can control the dynamic range to “fit” that of your camera. These filters typically come in 1, 2 and 3 stop variations with either a soft or hard transition zone on the filter. These filters are rectangular and fit into a holder so you can adjust the transition zone to suit your scene. The most popular manufacturers for these filters are Lee, Hitech/Formatt and Singray.
Neutral Density Filter. These filters have been around for some time. The main usage is to allow slower shutter speeds than the when the ambient light level will allow. For example, you want to photograph a waterfall and exposure is 1/30 at f/16 using ISO 100 but you need a shutter speed of ½ second for the effect that you are after. You could use a 4 stop ND filter to achieve this. Videographer’s also take advantage of ND filters so they can use fast lenses in normal ambient wide open for minimal depth of field. Lastly, there are also 10 stop ND filters made by Lee and Hitech for creative effects.
Variable Neutral Density Filter. These are a variation on standard ND filters in that you can adjust the amount of density similar to the way you adjust a polarizing filter, with a simple twist of a ring. So rather than carrying a selection of ND filters, one filter allows you to vary the density from 1 stop to over 6 stops.
These are the filters I like to use to add another dimension to my photography.