Lens flare

A lens flare can either be your best friend or your worst enemy, depending on if you want it in your image or not...

What is lens flare?

Lens flare is a photo effect caused by strong, non-image-forming light such as the sun, a full moon, or artificial illumination that looks like a haze or a starburst. The light enters the camera lens, hits the sensor, and scatters, creating the effect.

When light rays from a bright light source (such as the sun or artificial light) strike the front element of a camera lens, they can reflect and bounce off different lens elements, diaphragms, and even the sensor, potentially degrading image quality and introducing unwanted objects into images.

Simply put, it usually appears as a haze over a photograph. The shot was washed out by altering the contrast and washing it out. It can also appear as a starburst. The shape and size of your camera's aperture dictate the location and shape of the lens flare starburst.

The effect, also known as “lens flare,” can have various effects on images: it can drastically reduce image contrast by introducing haze in different colors, add circular or semi-circular halos or “ghosts,” and even add odd-shaped semi-transparent objects of varying color intensities.

However, flare is not always undesirable in photography; it can be used creatively to add artistic elements to images. In fact, lens flare is often used in movies and computer games to add realism and enhance the viewer's visual experience.

Theoretically, when a point of the light source, such as the sun, is much brighter than the rest of the scene, it either happens to be in the image (within the lens angle of view) or simply hits the front element of a lens without being present in the image. It can result in a lot of haze/lack of contrast, orbs and polygon artifacts spread throughout the image, semi-round forms with rainbow hues, or a mixture of all of the above, depending on the position of this intense light source.

This is caused by internal reflections within the lens and reflections between the imaging sensor and the lens.

What causes lens flare?

All cameras, except the simplest, have lenses that are made up of many "lens elements."

Non-image light that does not pass (refract) directly along its intended path but instead reflects internally on lens elements multiple times (back and forth) before reaching the film or digital sensor causes lens flare. Anti-reflective coatings are commonly used on lens elements to reduce flare, but no multi-element lens can completely eradicate it.

Light sources will still reflect a tiny portion of their light, and this reflected light will appear as a flare in areas where the intensity of the refracted light is comparable. Light reflected off the inside borders of the lens aperture causes a flare, which appears as polygonal forms. Although internal reflections are theoretically flare's origin, they often require very bright light sources to become noticeable (compared to refracted light).

The sun, artificial lighting, and even a full moon are examples of flare-inducing light sources. Even if there are no bright light sources in the photo, stray light can enter the lens if it hits the front element. Outside-the-angle-of-view light does not normally contribute to the final image, but if it reflects, it may follow an unanticipated path and reach the sensor.

Is lens flare good or bad?

Lens flare is not for everyone, and that is understandable. You have spent a lot of money on the best gear you can buy, and manufacturers have worked hard to create lenses with nano-crystal coatings to reduce flare and ghosting.

There is a reason it is there.

It always amazes me how many photographers use lenses with the lens hood flipped over the barrel. Perhaps they are all going for the artistic flair look?

If you are using filters and the lens hood will not fit over them, protect the lens with your hand. If you have a baseball cap, position it over the lens and fitters with the brim sticking out a few inches over the end of the lens. It is as simple as that: protect the lens from direct sunlight, and you are done.

Lens flares are viewed as undesirable and disturbing by some photographers, while others believe that when used properly and judiciously, they can be beneficial. To achieve an artistic appearance, some photographers purposefully shoot with a lens flare. It is also vital to consider where the lens flare is with respect to your subject.

It is possible that you do not want a lens flare to appear on your subject's face in a photograph. As a result, the angle at which you turn will determine where you see a lens flare in your image. It all comes down to your photographic style and whether or not you like it.

How to get rid of lens flare?

1. Lens hoods

A suitable lens hood can nearly eliminate flare generated by stray light from outside the angle of vision. Ensure the hood has a completely non-reflective interior surface, such as felt, and that there are no rubbed-off areas.

While it may appear that employing a lens hood is a straightforward solution, most lens hoods do not extend far enough to filter all stray light. Because lens hoods were designed for a wider angle of vision, this is especially problematic when using 35 mm lenses on a digital SLR camera with a "crop factor."

Furthermore, zoom lens hoods can only be constructed to block all stray light when the lens is at its widest focal length. Unfortunately, when it comes to light-blocking abilities, the larger the lens hood is, the better.

It is still important to make sure the hood does not obscure any of the image lights.

2. Influence of lens type

Lens flare is less common with fixed focal length (or prime) lenses than with zoom lenses. In addition to having an insufficient lens hood at all focal lengths, more intricate zoom lenses often have to include extra lens elements. As a result, zoom lenses have additional internal surfaces where light can reflect.

Wide-angle lenses are often intended to be more flare-resistant when exposed to intense light sources, owing to the fact that the sun will most likely be inside or near the angle of view.

Anti-reflective coatings are more common in modern high-end lenses. Some vintage Leica and Hasselblad lenses do not have any special coatings, and as a result, even in soft lighting, they can flare up quite a bit.

3. Use your hand or another object

Hovering your hand over the lens can easily block off sunlight and eliminate ghosting and flares. It is simple but works every time!

4. Use high-quality lenses

High-quality, pro-grade master lenses are expensive. But every item comes with a price and also brings extreme quality with it. These expensive lenses often come with amazing coating technologies that help significantly reduce or even eliminate flare issues.

5. Use prime lenses instead of zooms

Prime lenses, on the whole, feature simpler optical formulas and fewer optical parts than zoom lenses. The fewer elements you have to work with, the less flare you will see in your photos.

6. Change perspective/framing

Change the perspective/framing of the scene. Same with facing problems in our lives. Just changing the position of the light source in every shot can make a big difference.

7. Minimizing flare through composition

Flare is thus ultimately at the photographer's control, depending on where the lens is aimed and what is in the frame. Although photographers should never sacrifice their artistic freedom for technical considerations, certain compositions can be extremely effective in reducing flare.

The best solutions are those that combine aesthetic aim with technological excellence. One useful strategy is positioning items in your shot to block any flare-inducing light sources partially or totally. Even if the problem light source is not in the image, photographing from a position where it is occluded can help prevent flare.

Of course, the best method is to photograph with the problematic light source behind you, but this is usually either too restrictive for the composition or impossible. Even a minor shift in the lens's angle can alter the flare's appearance and location.

8. Visualizing flare with the depth of field preview

Depending on the aperture setting of the photo, the look and position of the lens flare fluctuate.

The scene appears in the viewfinder of an SLR camera only when the aperture is wide open (to supply the brightest image), thus it may not be a realistic reflection of how the flare would appear after exposure.

The depth of field preview button can be used to mimic how flare would appear at different apertures, but be aware that it can drastically darken the viewfinder image. The depth of field preview button is normally found around the lens mount's base and can be used to create streaks and polygonal flare forms. This button is still insufficient for modeling how "washed out" the final image will be, given the flare effect is also dependent on the exposure length.

Unfortunately, while keeping the lens cover on and knowing that you can block the light with your hand or other items is a smart idea, shooting directly into the sun and including it in the shot will negate your efforts. In certain cases, either entirely adjust the perspective/framing or use only high-quality lenses with multi-coated lens components.

Types of lens flares

1. Circular flare

Circular flares appear as circles or rings of light usually when a bright light source like the sun is just outside your frame.

2. Streak flare

Streak flares are streaks of light that shoot out from the light source. The streaks can be horizontal, vertical, diagonal, etc.

3. Starburst flare

Starburst flares create a "star" shape hence the name. These flares happen when you use a smaller aperture (higher f-stop number)

In conclusion, lens flare can be both a hindrance and a help to photographers. It is caused by the reflections created by the lens's components and is particularly prevalent when a point light source is present. There are many ways to avoid lens flare, including lens hoods, choice of lenses, and composition.

If you are a bit more daring, you can use this effect artistically. So, why not give it a go and see how to add that extra wow to your photos?