This is the final of three parts on the circular polarizer. In Part II we looked at how you can use the filter in order to maximize its benefits while handling most of its drawbacks. There is more of that kind of advice in this post, along with some practical tips that apply to any screw-on filter.
EFFECTS OF A CPL & HOW TO HANDLE THEM
- A circular polarizer appears to change the colors in some images. Mostly it’s the blues you’ll notice, but it can also saturate and brighten the warm tones. A good CPL will not cause much of a color shift per se. It’s more of an apparent effect and doesn’t happen in all images. But in any case if you’re shooting RAW it’s easy to warm (or cool) things a bit using the white balance sliders in your editing program. You can also get a polarizer with built-in warming.
- You may end up with uneven-looking blues in the sky when using a polarizer. It’s one of the main problems I run into when shooting landscapes with this filter. Patches of darker and paler blues, while they do occur naturally in parts of the sky, can be exaggerated with a CPL, making things look unnatural. If you’re using a wide-angle lens this effect is pretty obvious and hard to avoid. All you can do is rotate the CPL less and/or change composition. Try pointing the lens at a different angle to the sun and include less sky overall. If you’re using a lens with a longer focal length, pointing at right angles to the sun should give you an even effect no matter how much you rotate the CPL.
- Although a CPL often amps up your colors just the right amount, it can also hinder natural color saturation in some instances. For example, I’ve found in frontlight (sun is behind you shining on the subject), and with fall colors, using a polarizer will often take away a little vibrance. If it’s cloudy and the leaves are wet it may do the opposite, blocking reflections and allowing colors to come through as described in Part II. But be careful about using the CPL when shooting colorful subjects, especially in frontlight.
AVOIDING MARRIAGE BETWEEN LENS & FILTER
- Last but not least, let’s not forget about your threads. No, I’m not talking about clothes! It’s quite easy to tighten the filter too much on your lens. Then you can’t get it back off! A CPL is worse than other filters because you’re always rotating the filter element to adjust it, maybe tightening it even more.
- Prevention is the key. Getting a good filter with brass instead of aluminum threads will help. And of course, try not to tighten it too much. When you rotate the outer ring to adjust filter strength, occasionally go the opposite way (left). Just don’t do this much or you may rotate the filter right off your lens and drop it. Mostly rotate the same way you screw the filter on, to the right.
- More prevention: Keep your filter clean and lubricate. Use a hand-blower to get rid of little pieces of grit that try to get in between the rings. Also, occasionally lube the filter threads with silicone spray. Go outside away from your gear and spray the silicone into a small cup or bottle cap. Then use a Q-tip to carefully apply the lube to the threads and along the seam where the CPL rotates, avoiding the glass. Don’t use too much! Then screw the filter on and off your lens, rotating it back and forth a few times to spread the silicone evenly.
- If you get a filter stuck you can try a couple things. One or two fat rubber bands, like the kind on broccoli at the grocery, allow you to better grip the filter and perhaps the lens. Try not to pinch. Spread your fingers and use even pressure all around the filter. If a filter is really stuck, try this: Get some of that tacky rubber material made for lining drawers & shelves. Cut a couple flat squares and on a table lay your filter flat on one of the squares. Spread the other square flat and tightly onto the filter’s outer ring. Using your palm or fingers evenly spaced around the rim, gently and evenly press down while twisting to the left.
Thanks for reading. Enjoy your weekend!