Often called a “do-it-all” lens, the 24-70mm is useful when the production team does not know exactly what the day will require. Photo by Sirisvisual on Unsplash
When it comes to capturing images in still or video, lenses are one of the most important factors for controlling your image. However, the generic term “lenses” can cover a huge spectrum of meanings, glossing over some of the very aspects that make a lens unique. Just saying you have a lens alone doesn’t tell you zoom range, aperture, mount, or sensor coverage, all of which change what the outcome of the image is. This article is going to focus on focal length and usage. Even narrowing down to just this aspect leaves out important variables such as: kit lens or premium, zoom or prime, standard or cinema. Obviously, this article could very easily become a book; to prevent that, this will be a primer on focal distances and use and is far from comprehensive.
Wide lenses reveal the room. Long lenses control attention.
First things first, focal length is the distance from the optical center point of the lens to the sensor. What this results in is the angle of view, or how wide or narrow your image is going to be. To set a baseline, humans can see 180 degrees, but most of that is located in our peripheral vision, so it is blurry. However, our central vision is an area of about 45 degrees, which is going to be equivalent to somewhere between 35mm-50mm. That means shooting with a 16mm lens is going to capture details far beyond what you can see looking straight ahead. Conversely, a 200mm lens is going to see more details much further away but with less of the overall field of view.
So here are some standard lens focal lengths and what they tend to get used for:
12mm-24mm
These lenses have an enormously wide field of view, between 100 degrees and 84 degrees horizontal. Optically, this is far wider than your central vision. That width has some tradeoffs; sometimes it makes things like straight lines curve. Chances are good you have seen photos like this, maybe of buildings where the lines simply aren’t straight. The wide aspect can also exaggerate the perspective if the subject is up close.
These lenses succeed at things like astro photography, landscape, and real estate photography. On the video side, they can be used for great establishing shots or for BTS of the congregation, especially in a large venue.
35mm
A standard; often, you will hear lenses listed as a “35mm equivalent,” which is a comparison to 35mm film stock. This is an interesting lens because it falls wider than our standard field of vision but not so wide that it distorts the image. Also, as a prime lens, it trades zoom for aperture. The 35mm is going to be f/1.4 or f/1.8 as opposed to the kit wide zoom, which is going to be f/3.8-5.6 variable unless you fork out the extra cash for a constant f/2.8. This lens will be brighter and have a narrower focal plane than a zoom lens covering this same focal length. This lens is great for street photography, and some portraiture if you are looking to include some of the surrounding area, not just a subject.
For video, these get used for documentary and interviews because it’s wide without sacrificing a natural look; since 35mm is close to what the human eye sees, this lens doesn’t feel odd to the viewer.
24mm-70mm
This is what most photogs would consider their everyday lens. It covers your main field of view at 50mm but also gives you a little zoom on the 70mm, as well as a little more width on the 24mm. Quite literally the jack of all trades lens, it can do everything. It, however, lacks the reach of a true telephoto, and the width of a wide lens. Typically, because it’s a zoom, it will have fewer f-stops compared to a prime of the same field of view. For photos, this lens is good at everything: portraits, landscapes, street photography, everything, but it’s just good, not perfect.
Better lens choices begin when church techs stop asking, “What will work?” and start asking, “What will this communicate?”
On the video side, like photography, this lens is good at everything. For everyday use, when you may not know what you are shooting today, this is the go-to. I had this on my main camera for years without taking it off. It does well at everything, but if you need something specific like a wide establishing shot or something telephoto, you will find this lens probably not wide enough or not long enough for “that shot,” but really useful at everything else.
50mm
The nifty 50, for many people it’s their first prime because it’s got a very natural look, falling almost exactly on your field of view. It doesn’t magnify objects, so images from this lens look “normal.” Since it’s a prime, it has all the advantages of f-stops. For photos, this is good for everything, full stop. It’s like taking a picture of what you see; it’s just good, not great.
In video, likewise, this lens is a good all-use-case lens; it simply works.
70mm-200mm
The go-to for sports and distant subjects. If you see a photographer on the sidelines at a professional sporting event, typically they use this lens. Great for getting tight to subjects at a distance and focusing attention.
For video subjects that are far away, like on a bike or jet ski, this is great at getting close. Also, if you are going to do lens zooms, this is the perfect lens because it covers such a wide distance, which can make the zoom dramatic. Good for events, especially if you pair it with something like a follow focus on the zoom ring, and use autofocus. This lens allows you to shoot like you are using an ENG camera rather than cinema or mirrorless.
85mm
Tighter than a 50mm tends to look the most accurate for faces, making it a good portrait lens. Also gets used for street photography.
For video, it can get dramatic close-ups, so it’s great for doc and interview shoots. Also good for b-roll that gets a different field of view from the A camera without feeling weird.
The right lens can turn a technically correct image into one that carries the emotion and energy of the moment. Photo by Rob Simmons on Unsplash
Beyond 200mm
At this point you are into specialty lenses that only make sense in very specific use cases. These tend to be sporting and wildlife, because the field of view is so far away that often you are looking at something hard to distinguish with your naked eye.
Choosing a lens is where image capture begins to move from technical to artistic.
200mm or more in video is going to have to be an intentional choice because the camera will be very far from the subject. There are some absolute use cases, but they are going to be outliers; this is not an everyday lens. This is the type of lens you rent when you need it because they tend to be very expensive, especially the fixed aperture versions of this lens.
Now those in the know have already figured out these fields of view are based on a full-frame sensor size. Now full frame lenses tend to work just fine on smaller sensor cameras, provided the mount is compatible or adaptable. The field of view of those lenses changes because they are only utilizing a portion of the entire image the lens can resolve. The math for the other two main less-than-full-frame sensors is easy: if it’s a full-frame lens on an APS-C sensor, it will be multiplied by 1.5, so your 10mm lens is a 15mm on a crop sensor. For an MFT sensor, it’s multiplied by 2, so your 10mm lens is going to be more like a 20mm. The result means it’s harder to get wide with APS-C or MFT sensors than with full-frame lenses. Conversely, if you are shooting something in the distance, say wildlife, that 400mm full frame will be more like 600mm on an APS-C or 800mm on an MFT.
You develop an eye for lenses by leaving the safe shot behind and seeing what another focal length can reveal.
However, smaller sensor lenses, while less expensive than their full frame counterparts, have a glaring issue. Certain focal lengths vignette, resulting in an area where the lens can’t resolve an image at all on part of the sensor, so it captures nothing, just black around the image. Which is why having a camera with a full-frame sensor that has an APS-C mode is really the best of both worlds; you get more reach out of your telephoto lenses without sacrificing your super wide-angle full frame for your wide lenses. However, if you are shooting photos, do your research because some cameras will take a significant hit on the megapixel when swapping from full frame to APS-C mode.
Lens choice is one of the things that moves image capture from technical to artistic. Technically, you can get an image of pretty much anything with any lens; it may not be good or useful, it may not communicate anything, but you can technically do it. The question you should be asking is “Why should I choose this lens?”
