Camera Lens Basics – Complete Beginner’s Guide for 2020

Well, the terminology kind of got lost on me at first. I wanted to admit that. I’m an amateur and so as I research, I’m learning, too! Let me break down a few things that might mean something different to you or that you might not understand. I’m the first to admit, I didn’t know this stuff and it’s pretty important to comprehend the camera lens basics before you pick lenses and maybe even cameras. 

camera lens basics - beginner's guide

Native thinking

For one thing camera brands have “native” lenses that can be purchased for use on their specific type of camera. If you stick with one brand, this can be both helpful and sometimes it can be a hindrance. Think about it, you’re a Canon lover – you have like 15 different lenses capable of all manner of interesting view-finding. Each lens can set you back anywhere from $130 to well over $1000. That’s a lot of investment, right?

But anytime you upgrade your Canon, you have all of these native lenses to choose from. Suddenly, your breath gets taken away by the new Sony camera! It has everything you ever wanted in a camera and then some. Do you buy it? Or do you wait and hope Canon fulfills your dreams with a camera comparable to the Sony – because you have so much invested in their native lenses? See what I mean?

The good thing is, sometimes there are adapters that can be used to fit lenses from one company onto cameras from another. They don’t always work well, and sometimes you cannot share between the big-brands (Sony, Nikon, Canon, Olympus, Panasonic, etc…). I’m finding that a lot of people really dig in and find out which brands of lenses other than native work well between camera lines.

I think this is a good idea. Sure, go for the Nikkor Lens when you have a great deal on it for your Nikon Camera. But also think about spending some money on lenses that can be adaptable to other cameras. 

Camera Lens Mounts & Adapters

If you want to go into further detail about this, please look up the article from B&H on lenses as it contains a lot of pertinent information and it also has an awesome chart for comparing various, popular camera models –

Adaptability for lenses has to do with the lens mount a camera has. A lens mount is an interface of sorts. It’s mechanical and often electrical – the interface between the camera and whatever interchangeable lens you may want to use. Lense mounts are proprietary – meaning they limit compatibility between the lenses and the manufacturer’s camera.

The mounts allow electronic communication between the camera and the lens so that you can more easily control focus and exposure. In most newer camera models, the lens is attached via the lens mount by placing it correctly to the proper physical orientation and then twisting the lens to lock it in place (known as bayonet style).

In older camera models, you may run into thread/screw mounts which are probably self-explanatory or breech mounts that use a ring to tighten down the lens onto the camera. 

Another term that’s very important here is FFD or flange focal distance. FFD describes the length from the mounting flange (the edge of the lens mount on the camera body) to the image sensor or film plane. It varies from manufacturer to manufacturer, and can limit interchangeability of lenses to specific cameras.

The flange focal distance of each camera system is factored into subsequent lens designs, and is a constant length used by each manufacturer to ensure accurate focus from a specific lens’s minimum focusing distance to infinity. Using a lens with a specific FFD on a camera system with a shorter flange distance, you will not be able to achieve infinity focus. This distinction is the key element in which lenses can be used on camera systems other than the original one the lens was designed for, via a lens adapter.

Bjorn Petersen for B&H

I’ve always wanted to be able to use third-party lenses. For one, they’re usually not as expensive as the “brand name” lenses (Hallelujah!!!). Not to mention, I have a mirrorless camera that the hubs purchased recently that I need to work with. Mirrorless cameras have a shorter FFD – sooooo, what does that mean? Well, it means that you can theoretically attach any lens with a longer FFD to it by using a lens adapter.

Because an adapter is used to make up the difference in FFD between the lens and the camera. Like I said before, I’m just including the basics in my article, but if you want to see more detail about mounts and adapters, take a look at the B&H article. 

Lenses affect Aperture

Just to review from the article I posted on Photography Basics – aperture is measured in f-numbers. The numbers refer to how large the opening can be that allows light to pass through the lens. The smaller the number, the larger the hole; the larger the hole, the more light is let in; the more light is let in, the better images you can get in low light. 

Here’s an example from a zoom lens: 18-55mm f3.5-5.6 which means – the maximum aperture at 18mm will be f3.5, while the maximum at 55mm is f5.6.

Lenses and their aperture plays a significant role in “depth of field” focusing or what my Samsung Camera app calls “selective focus”. It means playing with the settings of your aperture  to make it as large as possible (the smaller f-number) so that things around a particular subject are out of focus, while that one subject is focused.

This is a style I love.  But as Bjorn points out, “…because the larger hole demands more perfection in the lens construction, it can be very expensive to achieve this, which is reflected in the price of a lens.”

Types of Lenses

Now that the basics in lens vocabulary have been discussed, we can get into the various types of lenses available to you. I will be covering Prime, Zoom, Telephoto, Wide-Angle, and Macro Lenses. 

Prime Lenses

A prime lens has no zoom. It has one focal length and that’s all you get (35mm, 50mm, 85mm, 135mm, etc). Because of that, it doesn’t have the moving pieces and mechanisms required to zoom. Therefore they are simple, and in that simplicity, the apertures can be wide and the images taken are sharp. Prime lenses are very useful for indoor and low-light situations. 

Prime lenses are also called “fixed lenses” aor may be called by a photographer by another name – their “normal lens”. If you want to add or remove certain elements from your picture, you will have to literally move yourself closer or farther away from your subject. Because of this, a prime lens makes you take your time while composing a picture. 

They can be less expensive and also lighter than a zoom lens, however, you might end up wanting to take more than one with you. Most photographers will grab a 50mm lens and call it a day. 

Among prime lenses, a normal lens is one that sees in similar proportion to a human eye allowing for peripheral vision, but not wide-angle. They are the most common prime lenses on the market. You’ll find they run from about 35mm to 50mm. These are great for street photography, portraits, documentary photography, and creating precise compositions, because the images will come out very much like what we see with our own eyes. 

Zoom Lenses

A zoom lens has a variable focal length – meaning you can adjust the length by using the mechanisms inside the lens. They are preferred by travelers and hobbyists and usually come in most camera kits. There are even things called super-zooms that can cover the entire range of focal points needed by most people.

Zoom lenses can make taking pictures in tough places more efficient – you can zoom in on a subject instead of having to move closer.  

There are drawbacks to these kinds of lenses, though. Obviously, they’ll be more expensive and heavier thanks to everything inside of them. You’ll also need to make sure their functions work correctly with the camera you have – they’ll be more finicky with adapters and mounts than prime lenses.

If you’re trying to cover such a huge range with a super-zoom, a lot of the time, you’ll not get as sharp an image as you would with more limited lenses. 

There are differences among zoom lenses besides the focal length. Remember, aperture is the measure of the diameter of the opening of your lens – the wider the opening, the more light gets to the film or your sensor.  Well, a variable aperture zoom allows the maximum aperture to change whether you are zoomed in or not. Fixed aperture zoom lenses remain at the same aperture through the entire focal range available.  

Just keep in mind that these kinds of lenses will be more expensive and heavier than a prime lens – after all, there’s more to them. 

Telephoto Lenses

Any lens that has a focal length of 70mm or longer could be considered a telephoto lens. However, most are over 100mm and go up to 200mm on average. There is also a subcategory called super-telephoto which is anything over 200mm (200mm, 300mm, and even 400mm).

They are the opposite of wide-angle lenses, shortening the depth of field and enabling you to isolate your subjects from the background.  The subject should be sharp, but everything in front of behind that subject will fall quickly into a blue with a telephoto lens. So if you want the dreamy background blue around something, these lenses help with that. 

These types of lenses are extremely useful when you can’t get too close to your subject. For instance, sports photographers and wildlife photographers use telephoto lenses quite often. Astronomy shots are also taken with telephoto lenses. 

Just keep in mind that these lenses can be very expensive and weigh quite a lot. You will want a sturdy tripod for these things, and don’t think of these things for carrying around when you travel on foot a lot. They quickly become cumbersome. Also, they eliminate the ability to capture a subject that is closer to you – so you might end up missing a good shot in exchange for the long distance one.  

Wide Angle Lenses

Wide angle lenses usually have a focal length between 17mm and 40mm, but their point isn’t about the length, it’s about providing you with a broad view of the scene you’re filming. The smaller that focal length number, the more you will be able to fit into the frame, but also keep in mind that the more you fit in the frame, the more distortion you are likely to get. Wide-angle lenses have three classes: Wide, ultra-wide, and fish-eye.

A regular wide-angle lens is pretty much anything shorter than 35mm. These can capture wide scenes, and have a much larger depth of field (more will be in focus, from the foreground to the background). 

An ultra-wide angle lens is one which has a focal length shorter than 20mm, but is built with internal lenses which are meant to correct the fish-eye distortion; these are sometimes referred to as “aspherical” lenses.

You can tell a fish-eye lens by looking at it because the front element bows outwards, allowing it to see as wide as 180 degrees. They are always less than 15mm in focal length. This gives the signature fish-eye effect (makes you feel like you’re seeing the world from inside of a fish bowl. It bends all straight lines around the center and creates a circular effect in the image. These lenses are fantastic for certain purposes, but around the edge, the image can be extremely distorted. 

Wide angle lenses are ideal for shooting landscapes, small interior spaces that need to look larger, or events like concerts where you are close to some subjects but want to give the viewer the feel for the entire crowd outside of the subject. They also come in handy for certain types of street photography and environmental portraits that need to include your subject’s surroundings. I know a lot of real-estate agents and architectural design photographers use wide angle lenses to capture their shots.   

The biggest downside of wide-angle lenses is that they can create distortion–they tend to stretch things out and make them look larger, especially elements that are close to your lens. A bit of advice, though – if you go for a prime lens to use as a wide angle lens, they are also fairly small and lightweight, so they make a great walk-about lens.

Macro Lenses

Macro lenses are used to create extreme close-ups of subjects. A mador lense can pick up the tiniest of details and can even enhance those for your shot. Because macro lenses can produce a life-size or even larger-than-life size scale image of tiny subjects, these types of lenses have provided for humanity a greater understanding of nature.

The shots you may have seen taken of the texture of a tree frog’s skin, the intricacy of an insect’s wings and eyes, and what plant pollen looks like – all of those were made using macro lenses.

I’ve also seen macro lenses used for cataloguing purposes. Think of people who need to take pictures of small things like postage stamps or bones for a museum. I’ve also seen a photographer use these lenses for things such as close up shots of rings for wedding photographs. So the applications vary.  

Generally, using a camera with a macro lens means that you’re also going to need a tripod to stabilize your shots. That tripod needs to be able to get your camera very close to the ground, either by inversion of the center column or just by using a table-top version of a tripod.

Some photographers or filmmakers of macro-footage just place their camera on the ground or use something to place it on, but that can be risky (getting dirt and posture in the camera) so be aware.  

Macro lenses also tend to produce images with a very blurry background, so you must be very careful and precise when you focus the lens.


I hope this helps you out when you’re looking over the types of lenses you may want to purchase in the future. It’s just the basics, but sometimes that’s all you need. If you want to find out more or go into more detailed information on these kinds of things, by all means, check out any of our other articles on this website. I am not an expert, I’ve just done a lot of research for myself and wanted to share it with you! 

Rachel Adams

I have used a wide variety of cameras over the years and wanted to share my experiences and knowledge with my readers. I don't have a degree in photography and I don't do this professionally. So, if you were looking for a photography expert - sorry. But if you prefer a practical person who admits she’s been a noob to photography and has learned from good people and through trial and error? I’m here for ya!

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