Application of circular polarizer CPL in landscape photography

Lead: CPL (circular polarizer) is a kind of filter commonly owned by everyone. Generally used in landscape photography to eliminate unnecessary polarized light and make the whole picture clearer and more transparent. But how can we use it to see the effect? This paper will introduce the skills, principles and methods of using CPL.

Examples of using circular polarizer CPL in landscape photography are:

1. Used in landscape photography, it can highlight the level of blue sky and white clouds or enrich the blue sky.

2. Eliminate reflections on the water.

3. Eliminate scattered light in snow.

4. Increase the saturation of color

5. Enhance the blue effect (note 1)

The author photographed the sunset glow of Gaomei wetland with a polarizer.

2.5s, f/ 16, 18mm, ISO 100, use tripod and turn off anti-shake.

Installation and convenient method of CPL

After purchasing CPL (matching the aperture of the lens, such as 77mn, 52mm, etc.) with appropriate size. ), install CPL on the lens. It should be noted that CPL is different from other filters. CPL contains two rotatable lenses, so remember to install one lens firmly on the lens and let the other lens rotate freely.

When using CPL filter, we need to turn the front lens of CPL and use the viewfinder to observe the picture. When we turn it to the angle you think is suitable, we can shoot by the shutter. Please note that if you change the camera from horizontal to vertical, you must readjust the CPL angle.

Skills of using CPL in landscape photography

Many times CPL will be used for landscape photography to eliminate unnecessary reflections and make the overall picture clearer and more transparent. But how to use CPL is effective? Just follow the following principles:

1. Don't face direct strong light or sunlight, as this will have no obvious effect;

2. To eliminate the reflection of the water surface, it is best to form an included angle of 45 degrees with the water surface, and the effect will be more remarkable;

3. Carefully observe the change of color saturation in the viewfinder (if it is the first time to use it, you can practice with the LCD screen, and while rotating, you will find that the LCD screen turns from bright to dark);

4. When observing the viewfinder, remember to turn it counterclockwise to avoid accidentally turning the CPL down because the lock is not secure enough;

5. To enhance the effect of the blue sky, there is another big principle, never go against the light, otherwise CPL can't save the gray blue sky.

In addition, in addition to the above examples, you can also use CPL. In fact, plant photography after rain is also a good opportunity. Because the plants that have rained will be covered by a little rain, polarized light will make the green color not green enough, and the overall feeling is gray. At this time, CPL can be used to obtain better color saturation and eliminate unnecessary reflection caused by water droplets or water films on leaves.

0.3 seconds, f/ 13.0, 40mm, ISO 100.

When shooting the sea or water surface, CPL can get a more transparent seascape.

1/80 seconds, f/11.30mm, ISO 100.

So how to rotate CPL to achieve the best angle?

Because the grating ring in front of CPL is not marked with a certain scale table, the practical significance of marking is not great, so everything depends on the angle between the object you shoot and the lens to determine where the best position for rotation is.

For example, if we want to shoot something in a glass cabinet, when our lens is parallel to the cabinet, the shooting angles are mostly parallel. At this time, the reflection phenomenon is usually not too serious without CPL shooting, but even if CPL is used, the effect of eliminating polarized light will not be significantly improved. Because the polarized light produced by reflection is almost perpendicular to the lens. Try to imagine that when light meets the reflection of an object, if the angle of reflection is close to vertical, then the light will move back and forth between the object and the lens. Even with CPL, there is not much polarized light that can be eliminated, and the rest is imaged on the photosensitive module. )

Then we change the shooting position, and then use CPL, the effect will be more significant, but how to rotate to the right position?

Because there is no scale on CPL, you should observe the viewfinder carefully after installing CPL. Is the original reflection slow at a certain angle when rotating the polarizer? In addition to practicing more, the main skill of sudden disappearance is actually not to be impatient when rotating, but to observe the changes of the viewfinder patiently.

Points of use: the place where the reflective part turns from bright to dark is the best angle to eliminate reflective light.

Now that CPL and viewfinder are mentioned, the author provides another convenient technique here:

Nowadays, due to the rapid development of optical technology and electronic technology, many SLR cameras have a second choice besides the traditional viewfinder: real-time viewfinder. Using LCD for framing and composition, the changes of light and scenery are also close to real-time changes. In the same way, after we install CPL, we can eliminate the influence of polarized light and get the correct angle and effect on the LCD screen. In addition, the exposure compensation of live view can also adjust the shooting parameters to the optimal exposure value, so that the whole picture presents an ideal exposure distribution, and the adjustment of CPL can also be presented more clearly, which is a big picture and bright feeling that optical viewfinder cannot provide.

CPL is generally composed of two optical lenses and a polarizing film, and the front rotating ring hardly indicates the polarization direction.

Pay attention to the shutter speed

Finally, I would like to remind you that after using CPL, the overall light intake will decrease, so the exposure time will increase relatively. If shooting in a dark place, remember to control the safe shutter time to avoid blurring the photo.

Note 1: Due to the mirror coating of polarizer, some polarized light will interfere and strengthen blue light.