Working With Polarizing Filters: The Benefits and Challenges
The Benefits of Using a Polarizing Filter
There are few more important things that a nature photographer can do to improve his or her photography than becoming familiar with the use of the polarizing filter. What can a polarizing filter do for you? Among other things it can darken the sky, remove reflections from water, and make foliage appear less shiny. Colour saturation is also significantly enhanced. It is the only filter for use with colour film that can do all of this.
Well, really what is a polarizing filter? It is a filter for sunlight that attempts to block out the light rays that often cause glare, while still allowing the desired light through. Designed with layers of filters that form right angles with each other, the system within the polarizing filter is generally quite effective. But, due to the way that the layers prevent some light from entering the lens, it is necessary to rotate the filter so that it allows the light you want to enter.
Working with the Filter
Since it's necessary to visually tune or adjust a polarizing filter, some people believe that it's not possible to use one with a rangefinder type camera, but that is not the case. Some manufacturers have created ingenious solutions to this problem, but there's also a simpler way. If you have a polarizer that has markings around the rim simply hold the filter in front of you while pointing at the subject and note the angle of the mark.
If it's at say one o'clock at maximum polarization, then put the filter on the camera and turn it so that the mark is again at one o'clock when it's on the lens. Heliopan polarizers are to be preferred for this reason because they have continuous numerical marks around the periphery of the filter which makes doing this quite simple.
Another easy solution for previewing the effects of polarization is to wear polarized sunglasses. Just remember when looking at a scene to tilt your head from side to side to change the angle of polarization. If this is uncomfortable, you could simply take the sunglasses off and hold them in front of you as you rotate them. If you wear prescription glasses, you can order them polarized the next time that you renew.
The Challenges
Be careful not to try to wear polarized sunglasses while looking through your camera AND at the same time using a polarizing filter. Using only one or the other is the best way. To use both, you would basically keep all light from entering and would more than likely see nothing as you attempt to take your shot. Thus, the solution is to use one or the other, but not both!
The second issue with polarizers and very wide-angle lenses is the thickness of the filter. By their nature polarizers are thick filters because they have a double ring, the first of which mounts the filter to the lens and the second which is the rotating polarizing element itself. If the lens is wider than about 24mm, when used at small apertures the edge of the ring can cause vignetting at the corners of the frame.
The solution is to buy a "thin" polarizer. One option is to buy a single polarizer of the largest size that you need and then to buy step-down rings to fit it to your smaller lenses. However, this is not something you should attempt in the field if there are difficult weather conditions. In addition, be sure everything works before setting out and be sure that you are NOT using a wide angle lens, then vignetting will likely occur.
Yet, knowing the solutions for these challenges will help you to be able to enjoy all the benefits that polarizing filters offer. Get ready for some spectacular photos. Have fun in the field!
As you experiment with different filters that are right for your camera, check out some of our recent posts that might assist you in finding what works for you!
0 comments:
Post a Comment