We’ve all seen them, the cool-looking “ornament” on the front of a professional photographer’s camera. Are they merely for show? Or, do these stylish accessories actually have a purpose? Let’s dive into the what, why and when of these items and see if they might be a good idea.
What Are They?
The attachment that goes on the front of your camera lens is called a lens hood. In most cases, they come in a cylindrical shape, like a lampshade, or a fancier wave shape. The wave shape looks like a flower and is known as a flower, petal or tulip hood. These two types are specialized for certain lenses and situations, as explained below. There are also rectangular-shaped hoods, which are less common, but most of the points apply to them as well.
Why Are Hoods Needed?
An image is captured through the lens in a camera. Extraneous sources of light can enter from outside the area of view. These light rays pass through the lens and bounce around the edges, creating artifacts that are not part of the original image. This may lead to lens flare or glare, ruining the final photo.
Although it is not always perceptible, these anomalies often reduce contrast, giving a washed-out look. The darker areas of the image become lighter and the rest of the image gets whiter. How does one combat these outside rays of light from getting into the lens? Lens hood to the rescue!
A lens hood provides a physical barrier to the rays. It blocks them, similar to using a beach umbrella to keep the sun off sensitive skin. Continuing with the seaside analogy, newer lenses have “sunscreen”—special coatings designed to minimize lens flare and artifacts. Combine the two and your photos will be on track to reduce or eliminate unwanted anomalies.
Is There Another Reason To Use A Lens Hood?
Beyond stopping extraneous light in its tracks, there is another reason that many pros always keep a lens hood attached: protection. Similar to a UV filter, a lens hood provides a low-cost buffer for the exposed glass. When a camera takes a tumble, the hood might be the armor that keeps the hard ground at bay.
Beyond direct protection from bumps and bruises, the hood may also keep unwanted fingers from touching the glass. Fingerprints can be problematic, but when the lens is hidden behind a few inches of plastic, they become less of a potential issue.
Finally, dirt and other particles are unwanted due to their potential to scratch and become just a plain nuisance. The barrier of a lens hood might not keep out all junk, but it will definitely keep the lens cleaner.
Impact damage, fingerprints and particulate matter may not be the lens hood’s primary objective, but they are worthy reasons to consider as you decide to use one or go without. When you consider the cost of replacing the lens as well as the downtime from filming, the value of the lens hood is evident.
Why Are They Shaped Differently?
Aspects of the lens hood are informed by the focal length and type of lens. A longer focal length “zooms” in and has a smaller viewing angle. A wide-angle lens “sees” more of the environment and has a larger viewing angle. A prime lens has a permanent focal length compared to a zoom lens, which has a variable focal length.
As the focal length increases, the length of the lens hood can increase. Shorter focal lengths require shorter hoods. As the width of the captured area increases, the hood needs to be shorter to stay out of the final image captured. Thus, a telephoto lens may have a long hood while a wide angle lens will need a short hood to keep from being part of the picture.
Since prime lenses have fixed focal lengths, they more often use a round lens hood. A conical (round) hood doesn’t have variations on its edges, but when you know there will be no changes in the focal length, you can design specifically for each lens. Even so, a wide angle prime will most likely use a petal hood. Because the short focal length “sees” more of the environment, a conical hood will be visible in the frame.
A flower hood is engineered with the aspect of the image in mind. A photo is generally longer than it is high. The shorter petals go in line with the wider side, while the longer petals align with the shorter side. This allows for more light to get in as well as lessen the chance of the lens hood being in the picture, as might happen with the round hood. When you use the tulip hood, it is important to keep the sides properly aligned.
Another feature of a well-made lens hood is an inner lining of black flocking. This is designed to prevent light from bouncing off the interior of the hood, giving an even greater degree of protection from stray light. Although this might sound extreme, when one is serious about reducing lens flare, glare and washed-out images, it is one more step to be taken.
When part of the hood obscures the image, there can be darker areas as well as the hood itself being in the frame. Darkness is referred to as vignetting. Once again, with use and experience, the problems a lens hood may instigate become easy to spot and fix and can eventually be avoided altogether.
When Is It Appropriate To Use A Lens Hood?
Most professionals agree that you should always use a lens hood. Unfortunately, most entry-level camera kits don’t include them. This leads to lack of knowledge and reduced skill set when it comes to this camera accessory. Avoiding lens flare and washed out pictures might save that perfect shot.
When outdoors, stray light can enter the lens from many sources. The sun is a powerful illuminator that reflects off surfaces. Any of these errant light beams can enter your lens. At night, street lights, car headlights or even moonlight might cause artifacts in your photos.
Indoor shoots have many potential light issues as well, although most do not rival the sun in its intensity and reflection. Candlelight, firelight or regular incandescent bulbs might all cause problems that can be assuaged by a lens hood.
Light is the most important factor in crafting an image. Shaping the photo into a great piece requires focus on not only the illumination of the image, but also on the surrounding environment. The lens hood adds another item in our arsenal as we look to create that perfect picture.
It might also be helpful to point out when a lens hood might not be useful. There are a few circumstances where it would be counterproductive.
When Is It Best Not To Use A Lens Hood?
In general, it is advised that a lens hood is helpful in almost any situation if it is properly engineered for the focal length and other traits of the lens. The reasons to not use one are mainly physical and relate to the lens hood getting in the way of something.
When you have an internal flash or added flash up top, it can physically get in the way of the required light. The image will have a shadow of the hood in the photo. Similar to the way that a hood blocks extraneous light, in this case, it blocks light meant to be in the image.
If you are shooting a macro image and need to be extremely close to the subject, the lens hood can get in the way. Physically becoming a hindrance, this can be another problem area.
When using a filter that needs to be manipulated, the lens hood can become a burden. In this case, it might be best to use a filter mount that works with the lens hood and allows changes. This becomes a win-win as you still have the use of the lens hood.
The Final Decision
Looking at the (mostly) pros and cons of a lens hood, there is one final reason to consider. Beyond reducing lens flare and keeping good contrast and color saturation in your photos, there is a coup de grace yet to be discussed. Further than keeping your lens from impact trauma, dust and particulate intrusion, there is a higher purpose to which one can aspire. The final piece of the puzzle is that a lens hood makes your camera look cool and even more professional. There, it’s out in the open. Look awesome and make a great impression because now the secrets of the lens hood have been laid bare.
Taking great photos requires time, experimentation, patience and knowledge. Using a lens hood may increase quality and kick things up a notch. Take the time to learn how to do things properly, and then break the rules when need be. Good photography is art—step up and reach for new heights. A camera and its accessories are merely tools for the artist.