Hello, Volks! Welcome to Hohenfels and to our newest post. In today’s Tools of the Trade, we’re going to talk about filters.
Filters are glass that goes on the end of your lens. There are many types of filters, some for artistic purposes, some are for technical purposes, and some are to protect your lens.
The 2 basic set-ups are the square filter, which uses a holder that fits onto your lens, and the screw-in.
Most people use the screw-in filter. When selecting a screw-in filter, you must ensure that the filter’s diameter matches that of your lens. A 58mm lens requires a 58mm filter. The threads are universal, so moving from lens to another of the same diameter is not a problem. They come in many types, and are usually more widely available.
Square filters use an adapter ring that screws into your lens just like a screw-in filter. The ring remains in place when you switch your filters to another lens. Having one adapter for each lens allows you to move your filters easily from lens to lens, and back. Cokin makes the most common square filters, and they have several types and varieties. The basic and most common ones for our needs are the P series. With square filters, you have the extra advantage of staking several together without vignetting on your image.
The first filter you either did, or should, purchase is a UV. This is a cheap filter to place over the end of your lens. It limits UV radiation, but the main reason for having it is that it will protect the glass in your lens. Breaking a filter costs just a small amount to replace, whereas breaking a lens costs considerably more.
The next in the line of types is the circular polarizer, or CP. You can replace your UV with a CP and prevent vignetting caused by stacking your filters. It increases contrast and darkens blue skies. It can do a lot more than that, including improving the color contrasts. The main feature beyond that is that when properly turned, it can remove reflections from glass, water, plastic, and most sources, except metal and mirrors. This effect is strongest when your light is approximately 90 degrees to your left or right with the lens facing forward. You use this lens by turning the filter’s twist ring until you obtain the desired results. Look for one that has good coating and no impact on your color balance.
Next up is the neutral density filter. These little gems can help reduce the light to your sensor, allowing for slower shutter speeds and nice effects in fog, or when shooting running water. They are great landscape tools, and properly placed in a shot can darken the sky, while allowing the landscape portion to be shot at a decent shutter speed. They come in numbers like 1, 2, 3, 4, etc. When numbered this way, the numbers refer to stops of light. 1 being a 1-stop reduction in light, and so on. The other system used to rate them in their density, in .3 increments. Each .3 increments equates to one stop. ND filters do not change the colors, as they pass light of all colors equally. When used on extremely bright objects, they increase contrast and improve image detail. There is also a graduated ND, which is an ND filter with reduction only about halfway down the length of the filter. This allows for darkening a sky while allowing the remaining portion of the image to remain unaffected.
Black and white photographers use colored filters to change to light hitting the film or sensor. Red filters pass red light and darken green and blue. Green filters pass green light and darken red. There are a whole series of color filters for both black and white and color photography. Most are labeled by their Wratten numbers, for instance 81A is a light warming filter. The Wratten system is available online and filters using this designation can be purchased online.
There are filters to soften the contrast, and other special effects, including adding starbursts, grids, and to increase the magnification of a lens. By knowing something about filters, you can get the right kind, and the best one for you and your photography.
There are shops in the local area, including Amberg and Regensburg that carry the different types of filters, and you can any of them online. Try to get a decent one, as low-end filters can add colorcasts and vignetting that will leave you wishing you hadn’t used a filter.
Enjoy the rest of your week! Surrounding the Hohenfels area are towns and sites worth shooting and adding a filter can make your art that much better.
Remember to get out and shoot with your filter and share your pics and questions by posting at the Hohenfels Volks Facebook page, and or by commenting here!