CPL Filter: An Ultimate Guide about CPL Filters

CPL Filter

Now photographers have a whole arsenal of tools – modern digital cameras, lenses, tripods, additional equipment and, of course, CPL filter in their photography kit. These all are different, and are used depending on the specific situation and the task that the photographer sets for himself. Today we are going to discuss about CPL filter in this article.

The CPL filter for the lens deserves special attention. Every good photographer or specialist has it. You can mount it on a lens on a sunny day to eliminate glare from non-metallic surfaces. The colors become more saturated; the brightness of the sky blue is smoothed out.

It is also possible to get rid of the haze when photographing objects from a distance and from the glare of glass and water when photographing bodies of water. The position of the filter can be adjusted to obtain the desired shades in the photo, which cannot be achieved through processing.

Definition: What is A CPL Filter?

CPL filter (where CPL stands for circular polarizer linear) is a glass made device attachment that is screwed onto the lens and allows you to remove part of the glare and reflected light from the formed image. In fact, it is used on camera lenses and DVRs in order to remove glare and light caused by sunlight reflected from various surfaces – glass building, landscapes, car windshield, dashboard, etc. The result of such filtration of the luminous flux can be a better and more contrasting image.

Since the filter’s job is to remove some of the reflected light, it can be concluded that the overall illumination level of the resulting image may become lower. This leads to the main disadvantage of using it – at night, the image quality can suffer. At the same time, in conditions of insufficient lighting, the CPL filter does not play any positive role, therefore it is better not to use it at night.

How It Works?

A CPL filter converts and traps polarized light. To achieve this effect, a special polaroid film is installed between the filter glasses. The outer glass rotates freely, while the inner one is rigidly attached to the lens.

CPL Filter Uses

The photographs taken with the use of a light filter do not have glare, which may appear when shooting wet surfaces, glass. For example, a filter will help to make the water deep and clear. You can photograph the bottom in great detail. It is important to note here that the CPL is capable of removing reflections in only one position. In certain places, it either weakens them a little, or does not touch them. It is also impossible to remove glare from metal objects.

A polarizing filter is irreplaceable when photographing landscapes. Choosing the correct shooting direction produces a stunning saturation and contrast enhancement effect. The sky becomes dark blue, the clouds become brighter and more expressive. By rotating the outer part of the filter, the photographer can add richness to colors, achieve a change in shades.

Uses: Why Use CPL Filter?

Using a polarizing filter allows you to block or convert polarizing light that is reflected off shiny surfaces. For this, a film is placed between two glass lenses. By turning the upper ring of the filter, you can adjust the degree of blocking of light polarization.

The filter simply cut off unnecessary stray flares. Typically, a filter is used when shooting on a sunny day. Reducing the amount and brightness of glare and increasing color saturation is achieved by CPL Filters. The filter will have no effect if the sun is in front of or behind the photographer.

CPL Filter Uses

The point is that both the tree and the leaves are also have the reflective surfaces. They, of course, reflect not like a mirror, but it is quite enough to fade under the direct rays of the sun. In fact, the sun’s rays that prevent us to take pictures fall at different angles. This is one of the rules of nature: “the angle of falling light on any surface is equal to the angle of reflection”.

Please note that the glare of metal cannot be removed using a filter because the light from the metal is so polarized, but from glass, plastic, water – easily.

Also keep in mind that the filters do not work at all angles to the sun’s rays and is almost useless in cloudy weather (you can only remove glare, but the color will not change). The best results are achieved when the sun is at the side of the lens. The worst part is the backlight.

Tips for Using Circular Polarizing Filter?

At first glance, you can find the same filters from all manufacturers, but on different prices. The cheapest are thick-rimmed glass filters.

More expensive models have a thin frame that eliminates vignetting when used on a wide-angle technique. Experts recommend not to save on this device and advise you to purchase a quality product that will last a long time.

A few tips for using polarizing filters:

  • do not use on ultra-wide-angle lenses, as it will be difficult to achieve uniform polarization,
  • the subject should be at right angles to the photographer, this will maximize the effect; if the sun is behind or in front, the result of using the filter will be minimal,
  • the effect will not be in diffused lighting, for example, on a cloudy day,
  • installing this type of filter on top of another can produce a vignetting effect, reduce light transmission,
  • shooting through glass, for example, window glass, can give an unpredictable result.

What to Look for When Buying A CPL Filter?

Quality filters are not cheap. So, experts do not recommend spending money on filters that cost less than $25.

Moreover, if you use different lenses, another problem arises – either buy a filter for each of them, or use an adapter. The easiest way out of the situation is to decide on the object you use most often and buy a device just for it.

First, select the desired type of device – linear or circular. The second is required for digital cameras with autofocus.

Next, you need to understand which mount is convenient for you. It can be threaded or screwed onto the lens.

It is important to pay attention to the materials from which the device is made. Look through it at the sky or a computer screen. Cheap devices will give interference in the form of a blurred picture, an odd image. This will especially affect the quality of the photo when shooting with a camera with a high-quality matrix.

Ask the seller for several models and take the same shots to compare the result at maximum magnification.

For good SLR cameras, devices are selected by diameter, it is indicated by the manufacturer on the packaging and on the device itself.

By manufacturer, filters can be conditionally divided into the following categories:

  • Best Quality: B + W Nano, Marumi Super DHG, Hoya Super HMC,
  • Medium Quality: B + W Pro, Marumi DHG, Hoya HMC,
  • Waterproof: B + W, Hoya HD, Marumi WPC CPL,
  • Standard: as a rule, all of low quality.

Devices of average quality at a more affordable price can retain almost all the properties of favorites. In particular, it is worth noting the products of the Marumi Company. With high quality, their price remains quite affordable. However, they do not offer innovative solutions, but simply make good filters for permanent use.

You may also like to read: Camera Lens Filters: Do You Know What Lens Filters Are and What Are They For?

According experts following CPL filters are among the best polarizing filters:

Marumi DHG Super CPL. It has an ultra-thin frame so it can even be used with 16mm lenses. It gets dirty quickly, and sometimes it is difficult to clean it, but it solves its tasks confidently. Manufactured in Japan. It is worth noting that Japanese companies are confidently pushing German manufacturers, who were not so long ago the undisputed leaders.

Marumi DHG Super CPL
Marumi DHG Super CPL

Carl Zeiss T POL Filter. They are distinguished by a thin frame, low weight, lightweight construction. The cost is quite high, but it is justified by the excellent quality.

Carl Zeiss T POL Filter
Carl Zeiss T POL Filter

Hoya Super HMC. The main disadvantage is the lack of threads, which makes it impossible to use them simultaneously with other types of filters.

Hoya Super HMC
Hoya Super HMC

B+W KSM Nano. The manufacturer uses an additional eighth layer without disturbing the color balance and light transmission. They are also equipped with a hydrophobic coating that allows moisture droplets to roll into balls and remove them from the glass. Brass mount reduces the risk of the device sticking to the lens.

B+W KSM Nano
B+W KSM Nano

Thus, if not a professional, you can choose models of the middle price category, which, at an affordable price, will provide the highest image quality.