Photographers often talk about using “normal” lenses for their work. What they are referring to is a lens that mimics the field of view of human vision. In general, most photographers would agree that a focal length of around 50mm on a full-frame camera is considered a normal lens.
What exactly is a normal lens? The standard litmus test is a lens that takes a printed picture of a scene held at arm’s length that matches the perspective of the real world when viewed with one eye. Over the years, photographers have debated back and forth about the right focal length, and it generally ranges between 40mm and 60mm for a full-frame camera.
The truth is that the answer is somewhere around 50mm for a full-frame (1.5″ or 35mm) sensor. This focal length changes depending on which sensor or film format you use. For example, a large format 8×10 film camera needs a 300mm lens to look normal, while a cell phone camera needs a 4mm lens to look normal. Here are some normal focal lengths for different imaging formats:
- 150mm focal length for 4×5 wide format
- 75mm focal length for 6×4.5 medium format
- 50mm focal length for full-frame sensor cameras
- 35mm focal length for camera with APS-C sensor
- 25mm to 30mm focal length for camera with half frame sensor
Varieties of 50mm lenses
50mm lenses are extremely popular and come in a wide variety of options. Within a brand, lens manufacturers often offer at least three options for 50mm lenses, each with different maximum apertures and focusing technology. For example, Nikon currently offers seven 50mm lenses for DSLRsincluded:
- 50mm f/1.2 manual focus
- 50mm f/1.4 AF-D
- 50mm f/1.4 AF-S
- 50mm f/1.4 manual focus
- 50mm f/1.8 AF-D
- 50mm f/1.8 AF-S
- 50mm f/1.8 AF-S Special Edition
Sony, Canon, Sigma, Tamron, Tokina, Zeiss and Leica all offer a plethora of 50mm primes to choose from, making the 50mm normal lens one of the most popular in the world.
Advantages of a normal lens
There are some obvious advantages to owning a normal lens.
50mm lenses typically cost between $150 and $400, making them some of the most affordable professional-quality lenses available. In fact, one of my favorite lenses is the Nikon 50mm f/1.8 AF-D. It’s an older lens, but you can still find it on sale for around $110 brand new. You can often find them for less than $80 on the second-hand market. Leica lenses are the outlier here, with some of their m-mount 50mm lenses costing many thousands of dollars each.
The large maximum aperture of 50mm primes is one of the main reasons to buy one. These lenses often come with a maximum aperture of f/1.2, f/1.4 or f/1.8. As a result, you can shoot in very low light while still using reasonable shutter speeds and ISOs.
Excellent control over depth of field
The wide aperture allows photographers to separate the subject from the background by using a shallow depth of field. This creates an image where the subject is sharp, but the background is blurred. A 50mm prime lens makes this creative composition very easy to achieve. At the same time, the photographer can choose a smaller aperture such as f/11 or f/16 to keep the background sharp.
One of my favorite reasons to use a 50mm lens is that they are small and light. When I mount one on a larger DSLR or mirrorless camera body, the setup seems downright small compared to my larger f/2.8 zooms. For this reason, 50mm lenses are ideal for street and travel photography.
Disadvantages and challenges of using a normal lens
Using a normal prime lens does have some drawbacks and challenges.
No zoom functionality
Obviously, shooting with a 50mm prime lens means you can’t change the focal length while shooting. This can make it difficult if you can’t change your physical position. However, if you can move, you’ll need to change your framing and composition by moving the camera’s position.
Critical focus when wide open
If you shoot your lens at f/1.8 or f/1.4, the depth of field is very shallow. Sometimes the depth of field is only a few millimeters. Therefore, if your subject moves during your image, their eyes will be out of focus or the flower will be out of focus. You have to be extremely diligent when shooting wide open.
Do you have a “regular” lens for your camera? If so, what do you like or dislike about it? Let me know in the comments below.