Perhaps every photographer has come across a protective filter for camera lenses. They are often advised when buying a camera or lens. But when are they needed? How to use them correctly?
Nothing in our life lasts forever; we need to try to preserve those lovely and necessary things. To keep the lens intact and safe, you need a protective filter. Dust, dirt, water – all of these very quickly destroy the lens. Protecting the lens at any cost is an essential task of a protective filter.
What is A Protective Filter, and How is It Different from An Ultraviolet Filter?
From the name, it is clear that such filters must protect the camera’s front lens from damage. Today, protective filters are understood to be two classes of filters: protective and ultraviolet. Simple protective ones can be marked with Protect, Clear, Neutral, and other variations, while ultraviolet ones have a clear UV designation.
A protective filter for the camera lens is a mechanical device made with glass, plastic, and other materials that protects our camera lens from dust, dirt, and splash of water.
In the days of film, UV and UV filters were different tools. But now the situation has changed. What is the difference between a safety filter and a UV filter? The protective filter does not affect the light passing through it, including not blocking the rays of the ultraviolet spectrum, while the UV filter blocks rays with such wavelengths.
When shooting with film, blocking UV rays was extremely important: the photographic material was sensitive to ultraviolet light, which is why shots taken on a sunny day often lost contrast, went into blue tones.
There is already an ultraviolet filter on the matrix of a digital camera, so the additional UV filter does not have any visible effect; its functions are also reduced to protecting the front lens from damage.
Contrast, color saturation, and image volume will depend not on magic filters but lighting. Finding the right light is the photographer’s job.
When choosing a protective filter, look for UV-labeled filters, which specify which wavelengths they block.
To determine which protective filter is needed for your lens, it is enough to know only one parameter – the diameter; it must be written on the lens and the inside of the lens cap. There is one logical pattern here: the larger the filter diameter, the more expensive the filter. And if you spend $10-15 for a 52 mm filter, then at least $30-40 for a 77 mm filter.
If you want to protect the lens and get effects (say, increase the contrast or remove haze when shooting a landscape), get polarizing filters, which in many scenes can improve the pictures.
Negative Effects of Using A Protective Filter
Any glass mounted on a lens becomes part of its optical design. Even the best protective filter will negatively affect the quality of images due to additional glare, re-reflections, loss of detail.
Often photographers shoot with hard side or backlighting (for example, sunrise, sunset scenes). At this moment, any light filter noticeably catches glare. To unleash the full potential of your technique, letting the robust anti-reflective coating of modern lenses work properly, shoot without protective or UV filters.
You may also like to read: Camera Lens Filters: Do You Know What Lens Filters Are and What Are They For?
Why Use a Protective Filter on the Lens?
Sometimes photographers, having bought a protective filter, immediately put it on the lens and not take it off. It is a mistake. Firstly, the quality of the images decreases: the sharpness drops, a lot of glare appears. Secondly, sometimes a light filter installed for a long time simply “sticks” to the lens barrel, and this issue can be resolved only in the service.
By itself, the front lens of modern lenses is not that delicate. Manufacturers often apply protective compounds to it. Nikon’s modern lenses use ARNEO coatings and Nano Crystal Coat to help prevent lens flare and chromatic aberration. In addition, the lenses are coated with a durable protective fluorine coating.
Thanks to it, splashes easily roll off the lenses, fingerprints are removed. And to leave a scratch on the lens, you either need to do it on purpose or be highly careless about the technique. If you use the lens carefully and do not carry it without a cap in your purse, mixed with keys, then it is unlikely to need additional protection.
Some protective filters (especially those with thin frames) do not hold the lens cap well. It can detach from the lens right in the camera bag and damage the protective filter with its hard edges. The latter, unable to withstand the pressure of the cover, may burst and scratch the front lens of the objective. It is a natural and not an isolated case from my experience.
These arguments lead to a simple conclusion: a protective filter should not be fixed on the lens all the time. But even if you want to always wear a protective filter on the lens, you must remove it when using other filters: polarizing, neutral gray.
Firstly, a “sandwich” of filters will further reduce the quality of the photo. Secondly, on wide-angle lenses, the frames of the light filters will start to fall into the frame, forming darkening and vignetting at the edges of the picture. Also, the protective filter must be removed in case of shooting with hard side or backlighting in the evening city to avoid glare.
You may also like to read: Polarizing Filters: An Ultimate Guide for the Beginners.
When is A Protective Filter Needed?
A protective filter is not permanently worn on the lens. It is installed when there is a real danger of damage to the front lens. For example, you are filming a sea storm or a stormy waterfall. In this case, it is worth using a protective filter so that water does not get on the lens. “Dusty” and “dirty” photography, filming sociable animals that strive to lick your lens, are also reasons to install a protective filter.
Reporters often use a protective filter instead of the front lens cap: you can put the filter-protected lenses in a photo bag without the lids and then quickly use them to shoot. The protective filter is not afraid to get dirty or scratched because it is consumable: it is replaced with a new one in case of wear.
You may also like to read: CPL Filter: An Ultimate Guide about CPL Filters.
How to Choose A Protective Filter?
It is essential to determine the economic feasibility of such a purchase. It makes no sense to buy an expensive light filter to protect a budget lens. At the same time, an inexpensive light filter will significantly reduce the image quality, and there is no point in it either.
If a protective filter is still necessary, determine the appropriate thread diameter for the light filters. It is indicated in the characteristics of the lens and on the back of the cap.
The diameter of the filter thread is often indicated on the lens itself; the Ø symbol indicates it. Also, the diameter is always displayed on the lens cap. In our case – 67 mm. If you are still not sure about the diameter of the filter thread for your lenses, you can always find it out in the lens specifications on the manufacturer’s website.
The filter must have an anti-reflective, anti-reflective coating. A simple piece of glass without such a coating will firmly catch glare and reduce the image’s contrast. As a rule, “enlightened” light filters have MC (Multi-Coated) marking in their name. Different manufacturers may have brand names such as DHG, MRC, or HMC. The most affordable safety filters are not made of glass but plastic and should be avoided.
How to determine the quality of the anti-reflective coating, and therefore the quality of the filter itself?
Place the filters on a plain surface (sheet of paper) with a bright lamp above them. If there is a glare from the light on the filter, its reflection, then the coating leaves much to be desired. In our example, the right filter has the highest quality, and the median filter has the weakest.
If you intend to use an ultra-wide-angle filter (shorter than 24mm for full-frame, shorter than 16mm for APS-C format cameras), choose a thin frame filter. It will ensure you against darkening in the corners of the frame. The minus of the narrow frame is that the lens cap does not hold well on it.
Let’s mention the filter manufacturers who have a good reputation among photographers. Some manufacturers of photographic equipment produce filters under their brands. It is done, for example, by Nikon, Carl Zeiss. There are also companies specializing in producing precisely light filters: Hoya, Marumi, B+W, Rodenstock.
Additonal Accessories for Protecting the Lens
The question arises: does the light filter protect the lens so well? Front lens, perhaps yes. But in most cases, when dropped, the impact is not on the lenses but the lens barrel. The most vulnerable part of the lens will be the protruding trunk.
How can you protect the lens without compromising (and in some situations, improving) the image quality?
The manufacturer supplies a hood in the kit for all Nikon lenses, except for the most affordable “whale” models. A hood is a visor that is attached to the lens and protects the front of the lens. The primary purpose of the hood is glare protection. The most unpleasant “hares” fall into the lens when light hits the lens from the side. The hood covers them from side lighting.
The shorter the lens’s focus, the shorter it’s hood because it should not fall into the frame. Some ultra-wide-angle lenses do not have round screw filters, but they do have a built-in hood. It resists glare and protects the large front optics. Example – Nikon AF-S NIKKOR 14-24mm f/2.8 G ED.
The hood also demonstrates excellent protective functions. It blocks access to the lens from the sides. Thus, it will be difficult to accidentally leave fingerprints on the lens or catch the front lens with, say, a tree branch. Due to its elastic construction, the hood also absorbs shocks.
So you can protect the lens during everyday use at no additional cost using the supplied hood. For a “whale” lens, a hood rather than a light filter will also be a more appropriate purchase.
Protective and UV filters do not improve the quality of images and often cause a decrease in sharpness, contrast, and the appearance of unwanted glare. UV and protective filters do not have any artistic effects on the digital frame. If you need effects, look for polarizing filters.
Protective and UV filters should not be fixed on the lens all the time, only when necessary: when shooting waterfalls, fountains, when working in the dust at races or on extreme travels, in reportage scenes.
It is better to remove such filters from the lens when there is a bright light source in the frame: the sun, city lights, a chandelier. Otherwise, there is a significant risk of getting unwanted glare. Before installing other filters, remove the protective one because the more filters, the lower the picture quality.
When choosing a protective filter, pay attention to products with UV marking. The light filter must have an anti-reflective multi-layer antireflection coating. When buying, it is essential to check its quality: no reflections should appear in it.
The most vulnerable parts of the lens are the rear lens and the “trunk” that extends when zooming or focusing. Their light filter will not protect them in any way. It is inappropriate to use an expensive protective filter with budget “whale” lenses. There is no point in an inexpensive filter either; it spoils the picture quality.
Almost all Nikon lenses come with a hood. It not only protects against glare but also provides mechanical protection for the front of the lens. Experience suggests that the equipment often gets damaged on the way to the shooting, not during it. The lens can be placed in the included case or wrapped in a large microfiber cloth for additional protection.
Are you using a protective filter for camera lenses? Have there been situations where that helped protect the lens? Share your stories in the comments.