Note: Here is a series of articles on various types of lenses. I publish these regularly.
Wide Angle Lenses
by William Lulow
While working with a student the other day, I found myself explaining about the qualities of wide angle lenses, so I thought I would update an article published last May about them. Each lens in a photographer’s arsenal has a specific purpose and reason for being. Each lens can capture the world in a different way. We have to know which one to use and when!
Now if you are touring or walking around looking to photograph scenes in general, a wide angle lens is a great one with which to start. With many of today’s cropped sensors (digital sensors that are a bit smaller than the normal 35mm frame), it’s helpful to realize that the effect these sensors have on lenses is to make them act a bit longer in focal length than they would be normally. In other words, a 20mm lens really functions like a 32mm lens with a cropped sensor. A “normal” wide angle lens for a full-frame 35mm camera would be in the 35mm vicinity. So, the 20mm with a cropped sensor would be just a little wider than normal. This is great for average images that show most of the scene and why they are great for general scenic photography while you are traveling, for example. This is really the lens I use most when I’m just visiting a place for the first time and want to get an overall sense of it. Then, if I see something I want to focus on I can either use the 20mm and move closer to the subject or I can, at that point, decide to use my 60mm macro or the 85mm short telephoto lens. Both the 20mm and the 60mm are light in weight and easy to carry around.
Note: Since I originally wrote this article, it seems that Canon does not make the EF-20mm, f/2.8 lens any more, or at least I haven’t found it on their current website. They do make a 28mm f/2.8 which is not quite as wide. But there are several of the older 20mm ones I found on eBay for around $250. Which is very reasonable for this lens.
I might add here that a few years ago, I gave up my zoom lens (17mm-55mm) because I found that the images from prime lenses were a bit sharper, but that zoom lens carried its f/2.8 speed throughout the range of the zoom. Zoom lenses are easy to use but they are heavier and, when used on their telephoto settings, act differently than when they are used in the “normal” focal lengths. So, you have to watch out for those differences. For example, many inexpensive zoom lenses do not carry their speed throughout all the focal lengths. If you have a lens with markings that say “f/3.5-5.6”, this means that in wide angle mode the lens aperture will open to f/3.5. But if you rack the lens out to its telephoto setting, all of a sudden it will only open to f/5.6. This can be disconcerting when you’ve already arrived at a good exposure setting and now you will have to change it. Here is an example of an inexpensive zoom lens that does this:
This lens is only around $300, but on its wide angle setting, it’s speed is f/4. At it’s telephoto setting, it is ONE FULL F/STOP LESS or f/5.6. The reason for the low price is that even though it is made by a name brand, it is not as good as one able to carry its speed through all focal lengths. That’s why a zoom lens able to hold a f/2.8 setting, say, costs five times as much! So, when you are buying any zoom lens, make sure it will hold its widest aperture through all of the focal lengths and be prepared to spend more. It will be much easier to use and will yield far better results. A great piece of advice: get the best lens you can afford. It pays to spend money on good optics.
Here’s an example of a good zoom lens:
This is a 24-70mm variable focus lens that carries its f/2.8 speed throughout the focusing range. Cost: $1,889!
One of the things that’s great about the wide angle lens is that when you focus on the foreground, most of the rest of the scene will be rendered sharp because of the great depth-of-field these lenses offer.
A “wide angle” lens is one where the elements are put together to bend light rays so that the image created encompasses more of the scene. The angle of view is anywhere from a “fisheye” (almost 180 degrees) to roughly 35-40mm (for a full-frame 35mm camera) where the angle of view is around 65-85 degrees. This type of lens will yield an image that shows most of the scene in front of the camera.
Wide angle lenses do several things:
- They show most of the scene
- They tend to render objects further away and thus smaller in the frame
- They can distort objects that are close to the lens
- They increase depth-of-field by expanding distances
- They sometimes create vignetting at the edge of the frame
You can use a wide angle lens in several circumstances:
- When you want to show a large part of a scene
- When you want everything in the scene to be sharp
- When you want to distort a particular part of a scene
- When you are shooting a large group
- When you are shooting a big landscape
When I shoot landscapes, I prefer to use a wide angle lens and focus on the foreground. One of the characteristics of wide angle lenses (as noted above) is their superior depth-of-field. So, to give my landscapes that sense of infinite focus, I use a wide angle lens and focus on foreground objects. Here is an example:
In this shot, I concentrated on the foreground and let the background just fall off. The important part of the shot was the grasses and water in the front. They are the largest objects in the field of view. They need to be sharpest. The depth-of-field would be taken care of by the lens opening (in this case f/16) and the wide angle lens. The boats and hillside in the background are acceptably sharp because of their distance from the camera.
When shooting with this lens (20mm f/2.8), I always concentrate on the foreground because details in the background would usually be too small to see really clearly anyway. When I did this kind of scene with a view camera on film, I could adjust the controls (swings & tilts) to create infinite focus with almost any lens. This cannot be done with a digital camera, so, since objects that are closer to the camera appear larger, it’s better to focus on them. When working with a wide angle lens, you usually want to have the foreground as sharp as possible. Sometimes the foreground can be rendered soft on purpose (such as when you want to concentrate on a subject in the middle of the scene). In that case, the foreground is not as important as the main subject and the soft focus can force the eye to concentrate on it.
In this image, the train cars in the foreground just serve to frame the main subject, which are the buildings of Hudson Yards in New York City. The strong composition lines are actually accentuated by the wide angle lens and serves to draw the eye into the frame.
Wide angle lenses make you think more about what you want to show in a scene. One reason is that because of the nature of the lens itself, it renders most things smaller than they actually are. That’s why the foreground is most important. Keep in mind the items above and do some experimenting to see what kinds of results you can achieve.
Here are a few images made with the 20mm wide angle lens on my cropped sensor Canon cameras:
In each of these images I was focusing on the foreground and just letting the background be covered by the lens’ depth-of-field, which on wide angle lenses is very great. One of the other caveats with these lenses is to try to focus on an object roughly about 1/3 of the way into the frame. This will ensure that the foreground will be sharp along with most of the rest of the image.
This is my “go to” wide angle lens:
The reason I like this lens for my crop-sensor Canon 90D is that allowing for the slightly smaller sensor, it functions as roughly a 32mm lens which is not really a super wide angle lens, but just wide enough to encompass most of a landscape where I need to show more than a “normal” lens. It is also fast enough, with a f/2.8 maximum aperture so that it can make images in relatively low light which works especially well at dusk. Here is an example:
