Taking outdoor pictures has tested many photographers in the initial stages of their photography journey. This is due to the unpredictable nature of the weather conditions out there. Unlike in a studio setup where you are in full control of the amount of light you want, out in the sun is different. For this reason, many professional photographers carry with them camera lens filters.

What Is A Camera Lens Filter?

A camera lens filter is a high quality glass accessory attached at the front of the lens to achieve beautiful effects in an image. This camera accessory gives some power back to the photographer to control what gets to the camera sensor.

While most argue that some of the functions of a lens filter can be done in post production, I beg to differ. For instance, once you capture reflections in your photo is there a way to correct that with software?

Besides, it is always advisable to take as perfect photos as you can in the field than to correct them with Photoshop and Adobe Lightroom. This is because you risk losing the quality of the image at some point.

What Are Camera Lens Filters For?

There are various reasons why you might consider adding a lens filter to your camera accessories kit;

To Protect Your Lens

We all know camera lenses don’t come cheap. Having a camera filter screwed at the front of your lens may save you some money in case something hits your gear. Since lens filters are cheap, it will hurt less to replace it compared to the very expensive Camera lens.

To Add Effects To Your Images

There is a clear difference between a photo taken without a lens filter on and where a filter was added. Some lenses will give you vibrating colors more contrast which regular lenses will just not offer. You can also eliminate reflections on glass and water surfaces.

To Correct The Exposure

Sometimes you are shooting in the midday when the sun is shining brightest. Adding a filter that will regulate the amount of light that gets into your camera may prove beneficial at this time. Adding a lens filter means you get to keep your exposure settings unchanged. This is very significant especially if you are a videographer.

Types Of Camera Lens Filters Used In Photography

There are a few kinds of camera lens filters used in photography. With the popular ones being circular screw-on filters, there are other shapes that lens filters come in.

These include square filters, rectangular filters and drop-in filters.

Circular (Screw-on) Filters

Just like the name suggests, this type of camera lens filter is screwed at the front of the lens. Circular filters are mounted directly onto the lens using the filter thread. This means that the diameter of the filter has to match that of the existing lens. Some camera lenses do not have a filter thread but for those that have, the diameter is indicated somewhere on the lens body.

Square Filters

This kind of camera filter is fixed at the front of a lens using an adapter. A filter holder can be used to stack one or more square filters to bring different effects at once. However, by doing this you risk losing the quality especially if the lens filters are made of plastic. Most square filters come in dimensions of 100mm x 100mm, 150mm x 150mm and 180mm x 180mm.

Rectangular Filters

Rectangular lens filters are more or less like square filters. The only difference is that one side is longer than the other. They are mounted onto the camera using an adapter and a filter holder. Rectangular filters have more space to move up and down giving the photographer more flexibility without risking high contrast areas.

Drop-In Filters

Unlike all the other lenses that are attached at the front of the lens, drop-in filters are mounted at the rear. This is achieved by adding a lens adapter which has a slot to fit in lens filters. Since drop-in filters sit behind the lens, you do not have to worry about the diameter of the lens. You can also easily change lenses without affecting the camera filter.

Having mastered the kinds of camera lens filters available in the market, lets us now go through the various types you can buy;

Ultraviolet (UV) Filters

This is the least effective lens filter used in a camera. The basic purpose of a UV filter is to eliminate ultraviolet light from hitting the camera sensor. This results in less hazy photos. However, modern lenses used in DSLR have inbuilt coding that meets this purpose. The only reason that photographers mount UV filters is to protect the front elements of a lens from dirt, moisture and scratches.

Polarizing Filters

Polarizing filters work by eliminating sunlight which has been reflected directly into the camera lens. This results in more vibrant colors and improved contrast in an image. Polarizing filters are also important in eliminating reflections in glass or water surfaces.

There are two types of polarizing filters; linear and circular polarizing filters. The two are named according to how they polarize the light.

Linear polarizer allows either vertically or horizontally polarized light to pass through. A circular polarizer is a combination of a linear polarizer and a quarter wave plate element. This filter regulates circularly polarized light and sometimes linear polarized light depending on the orientation.

To be perfect with polarizing filters you will need to put in much work as there are high chances of errors. For instance you may have come across photos in which the sky color is saturated in certain areas while the other is blown out.

Neutral Density (ND) Filters

Neutral density filter is a must have camera accessory for daytime shoot. This is because ND filters reduce the amount of light that gets into the camera lens. This translates to wide aperture for bokeh effect or slower shutter speed for long exposure photos.

ND filters are rated in stops of light from 1-10. The more stops of light your ND filter has, the more it is capable of blocking light. The filter can have a fixed number of stops (fixed ND filter) or can be adjusted (variable ND filter).

Variable ND filters are mostly used by videographers who have to work within certain shutter speed and ISO settings. As per the rule of thumb, your shutter speed should double the frame rate settings. For instance, if you are shooting at 25fps, your shutter speed should be 1/50th. If your video is too bright you can easily regulate the light by adjusting a variable ND filter without tampering with other settings.

Graduated Neutral Density (GND) Filter

Graduated neutral density filters which are also referred to as ND Grad filters work in reducing light just like the ND filters. However, this type of camera lens filter have a vertical transition between dark to clear. This brings balance when one part of your frame is overexposed. For instance when taking landscape photos and the sky is too bright, the darker side of the GND filter should be on the upper side. This will reduce the amount of light entering the lens from the sky while the lower clear side will not be affected.

GND filters come in three types depending on the transition from the dark to the clear side; hard-edge, soft-edge and reverse GND filter.

Hard-Edge GND Filter has a sharp transition from dark to clear. They are used to balance high-contrast scenes that are flat. An example of such a scene is taking photos at the ocean where the sky is bright. 

If the horizon is not flat, it is not advisable to use a hard-edge GND filter. For instance, if there are mountains then the hard-edge transition will be clearly visible.

Soft-Edge GND Filter has a smooth transition from dark to clear. Photographers prefer soft-edge GND filters over the hard-edge GND filter when the horizon is not flat. Such scenes include hilly landscapes, mountains or buildings.

Reverse GND Filter

Reverse GND filters combine the features of both soft-edge and hard-edge GND filters. One half of the filter is completely clear while there is a hard transition to a dark side which transits to a clearer upper side. 

Reverse ND filter is used to take sunrise or sunset photos. The clear half will fall under the foreground which is well exposed; the hard transition will fall in line with the horizon directly to the sun and the bright sky will fall to the less dark part of the filter. This results in a well balanced image.

A table showing an overview of camera lens filters used in photography

What To Consider Before Buying a Camera Lens Filter

Having gone through all the types of camera lens filters you might still be wondering which filter is the best for you. To have that answer you will need to ask yourself the following questions;

• What will be the purpose of the lens filter?
• What material is used to make the lens filter?
• What is the diameter of your camera lens?
• How much does the lens filter cost?

If you answer these questions then you will have a better chance to buy the best lens filter for your camera.