Written by 8:00 am Camera Settings, Photography, Photography Lenses • 45 Comments

What You Must Know About Full vs Crop Frame Sensors Before Choosing a Lens

You must be equipped with knowledge about crop frame and full frame sensors and lenses because not all lenses work on all DSLRs, even within the same brand.

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DSLRs have either full frame or crop frame sensors. Whichever you have will make a big difference on how you should go about choosing your lenses. Here, you will learn what the difference is and what it means for your photography.

“I got a new DSLR and I want a new lens. What should I get?” This was my aunt and, after a series of questions, I was able to narrow down what lens would probably make her happy based on her camera model. If you’re unhappy with the lens you have (or don’t have one at all) and you don’t know what you should use, find guidance in my straightforward suggestions below for new Canon and Nikon DSLR shooters. You must be equipped with this knowledge because not all lenses work as intended on all DSLRs, even within the same brand.

Narrowing down what lens you need can be divided into 3 steps:

Step 1: Identify Your Camera
Step 2: Identify Your Lens Type
Step 3: Pick a Lens (With Some Recommendations)

Let’s get started!

full-frame-vs-crop-frame-cameras-and-lenses

You must be equipped with knowledge. Find out if you own a crop frame or full frame sensor camera.

Step 1: Identify Your Camera

The model of your camera is important to knowing what lenses you should and shouldn’t use. Not every Nikon lens works well with every Nikon camera. There are some Canon lenses that simply will not work at all on certain Canon cameras!

Ignoring a few rare exceptions, Nikon and Canon DSLRs fall into 2 camps: APS-C Crop Sensor Cameras and Full Frame Sensor Cameras. There are lenses designed only for crop sensors and lenses that work fine with both. Here’s some Q & A to help explain the difference.

What are full frame sensors?

Every DSLR has an image sensor inside it. It is hiding behind a mirror and looks like a green rectangle. This is what conveys information that results in an image. It is what we popularly use now to make pictures instead of film. In fact, that is what a full frame sensor is – it is a digital version of a 35mm film frame. They are the same size!

SensorFilmBLCropAlexHuff

Same concept, different delivery. 35mm film next to a full frame 35mm sensor from a D800 camera.

What are crop frame sensors?

It’s a smaller sensor – smaller than 35mm. That’s it. That’s all it is. Imagine a 35mm piece of film, crop the edges down, and that’s your crop frame sensor.

Why would anybody crop a sensor?

The cynical answer is money. You can fit more cropped sensors on a silicon wafer during production than full frame-sized sensors so the yield is higher, making the cost lower. But there are other benefits. Crop sensors are smaller, which means the cameras they go into can be smaller. Crop sensors also have a narrower angle of view (they simply aren’t as wide as full frame sensors), which enhances the telephoto effect while reducing the wide angle affect. We’ll talk more about that later.

If full frame sensors match 35mm film, then exactly how big is a crop frame sensor?

Most crop sensor DSLRs use the “APS-C” format, which is a 3:2 ratio, as is full frame, but approximates the size of Advanced Photo System Classic film, which is closer to 24mm rather than 35mm. It was popular in the 90s in point-and-shoot cameras. In the digital age, APS-C sensor cameras occupy a formidable presence among pros and amateurs alike.

I heard crop sensor cameras have crop “factors”. What is a crop factor?

In the digital photography world, the 35mm size is our reference point for all imagery. We have all of these lenses available that are designed to work specifically on a standard 35mm frame size. But not all cameras have 35mm size image sensors! Many DSLRs have the APS-C sized sensor, which is closer to 24mm. When you mount a lens that is built for a 35mm size and stick it against a sensor that is 24mm size then the edges of your pictures are going to get cropped off. How much they get cropped is different on Nikon and Canon. Nikon APS-C sensors crop your image by 1.5x. Canon crops it a hair more, by 1.6x. This crop reduces your field of view through a lens by a factor proportional to the ratio between the 24mm size and the 35mm size.

Ok, so I’m going to see less on the edges of my scene through a lens on a crop sensor camera than on a full frame sensor camera. But how does that affect my lens choice?

When you cut off the edges of a scene, your field of view is narrower. If you’re a big fan of wide angle lenses because you like shooting wide scenes, you are going to lose some of that width on a crop sensor camera. How much? Simply multiple the length of the lens by the amount the sensor is cropped. In Nikon’s case, it is 1.5x – for Canon, 1.6x.

Let’s say you want to use a Nikon 16-35mm lens on a Nikon crop sensor DSLR:

16 x 1.5 = 24
35 x 1.5 = 52.50

Your 16-35mm lens will produce imagery on your crop sensor camera that looks more like what 24-52.50mm would look like on a full frame sensor camera. This is your focal length multiplier. You take your crop factor (in this case 1.5) and times that by the focal length you want to use. The result is how your crop sensor camera sees the scene in a world dominated by lenses designed for full frame fields of view. This will help you better choose a focal length that matches what you intend to see through your camera and not just what’s printed on the lens barrel.

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Full frame sensor image on the left and crop frame sensor image on the right. Same lens and position on both.

I’m still a little confused.

Another way to think about crop factor is this:

Full frame sensors measure approximately 43.5mm diagonally. So a baseline lens for full frame sensors, one with as “normal” of view as possible (not overly wide, not overly telephoto) is about 45mm-50mm. But for the smaller crop frame sensors, the diagonal is only about 30.5mm.

So a quick way to think about it is if you have a crop frame camera and your friend has a full frame one, you will have to use a 30-35mm lens to get the same approximate field of view as they do using a 45-50mm lens. If you are both using 50mm lenses, then your friend’s focal length is 50mm. But your apparent focal length is closer to 80mm. This is why it is really important to know what you’re shooting with before choosing a lens. You don’t want to purchase or rent a wide angle lens only to learn that your field of view isn’t going to be as wide as your expectations.

PhotographerCropSensorBorrowLenses

A visual approximation. This dad is using a 50mm lens on a full frame camera. His view is represented by the red box (his result is on the right). If he were using that same lens on an APS-C sensor camera, his view would be narrower (cropped) – which is resented by the blue box. If he wanted to get the same result you see on the right with an APS-C sensor camera, he’d have to either A) step backward or B) use a wider lens.

How to Tell Full Frame from Crop Frame Sensors

The specs will always say what kind of sensor you have. It will say either Full Frame or APS-C. It will usually tell you the crop factor, too. (1.0x, or no multiplier, for full frame and either 1.5x or 1.6x for crop frame – there are also cameras with 1.3x crops, but they are uncommon). Our own camera body listings on BorrowLenses.com will also note the sensor size. Here is a list of the most popular models for you:

Camera APS-C Full Frame
Canon 7D & 7D Mark II X
Canon 5D, 5D Mark II, 5D Mark III, 5D Mark IV X
Canon 60D, 60Da X
Canon 70D X
Canon 1D X, 1D X Mark II, 1D C X
Canon 5Ds, 5Ds R X
All Rebel Series Canons X
Canon 6D & 6D Mark II X
Nikon D3*, D3s*, D3x, D4*, D4s*  *Crop Mode X
Nikon D5* *Crop Mode X
Nikon D500 X
Nikon D7000, D7100, D7200, D7500 X
Nikon D700, D750 X
Nikon DF X
Nikon D300, D300s X
Nikon D5100, D5200, D5300, D5500, D5600 X
Nikon D3200, D3300 X
Nikon D800*, D800E*, D810*, D850* *Crop Mode X
Nikon D600*, D610*  *Crop Mode X

Step 2: Identify Your Lens Type

Now that you know what kind of sensor you’re using you can begin to choose the right lens for what you want to shoot.

For the most part, modern lenses (like their camera counterparts) fall into 1 of 2 camps: lenses for full frame sensors and lenses for crop frame sensors. One of the benefits of shooting with a crop frame sensor DSLR is that you can use full frame and crop frame lenses. But if you have a full frame sensor camera you should avoid using crop frame sensor lenses. Full frame cameras should only use full frame lenses. Crop frame sensor lenses are designed specifically to match the smaller size of crop sensors. The image coverage on these lenses is designed for a sensor smaller than full frame. If you try to pair a lens built for crop sensors onto a full frame camera then your images will have black edges around them. Full frame lenses work just fine on crop sensor cameras because the image coverage is 35mm, which is more than enough to cover the crop camera’s approximate 24mm sensor. You get image cropping, sure, but you can still shoot great images!

Here is an analogy to help you think of this in a different way:

Imagine you have a picture frame. If the frame is larger than the picture you want to put inside it, then you’re going to have weird empty space surrounding your picture. This is like the black vignetting you get when trying to use a lens designed for crop sensors on a full frame camera. Conversely, if you try to use a frame that is smaller than your picture, you have to crop your photo down – but at least you fill the frame!

Q & A time:

Ok, so crop sensor lenses have image coverage that is too small for full frame cameras so I should only use them with crop sensor cameras. But full frame lenses work just fine on both. Why would I ever use a crop sensor lens?

You still have to consider your focal length multiplier even on crop sensor lenses. Whether you opt to shoot with a lens designed for full frame sensor cameras or a lens designed for crop frame sensor cameras, the effective focal length of that lens will be either 1.6x more or 1.5x more when paired with a crop sensor camera. Lenses designed for crop sensor cameras don’t do the math for you and list it on the barrel. You still have to do your own math to get your effective focal length.

The major benefit of using lenses built for crop sensors is their size, weight, and price. Because they use a smaller image circle, it takes fewer materials to make long-range zooms. This is great for traveling and keeps these lenses relatively affordable.

Crop sensor cameras come with a lot of “lens math”. Do I have to do this with full frame cameras?

No. Full frame lenses are built for the 35mm size sensor so what it says is what you’ll get. You don’t have to compensate for cropping. This is why some people prefer full frame cameras (among other reasons not pertinent here). While full frame sensor cameras can’t use crop sensor lenses, they also don’t come with any need to calculate your focal length multiplier so long as you stick to the full frame lens inventory.

How can I tell if a lens is for crop sensors or for full frame sensors?

For Canon, full frame lenses are expressed as “EF” lenses while crop frame lenses are expressed as “EF-S”. If a lens has “EF-S” in the title, it is for crop frame sensor DSLRs and cannot be used on full frame cameras. If the lens’ title has “EF” (no S) in it, then you can use that lens on either full frame or crop frame sensor cameras.

For Nikon, if you see “DX” in the title, the lens is for crop frame DSLRs only. If it has “FX” in the title, the lens was designed for full frame (but can also be used on crop frames). Some Nikon cameras, like the D800 and D810, have a “DX Mode”.  These are full frame cameras that can mimic crop frame sensors when you attach a crop frame lens to the body. Sensor modes are becoming more common, which is great news for people who see the virtue of both modes and don’t want their lens choices to be limited.

sensor-lenses-differences

The major benefit of using lenses built for crop sensors is their size, weight, and price. Because they use a smaller image circle, it takes less material to make long-range zooms. This keeps these lenses relatively affordable and their small size is great for travel.

Step 3: Pick a Lens (Some Recommendations)

This is a lot of information to process. I remember my mind being blown at the discovery that some lenses read differently on different cameras because of sensor size. If you’ve come this far and understand most of what you just read but still feel a bit out-to-sea, fear not! I have some lens recommendations for new full frame and crop frame sensor DSLR owners. The first list is for zoom lenses, or lenses that cover a range of focal lengths. The second list is for prime lenses, or lenses that only have 1 length and do not zoom.

Introduction to Full Frame vs Crop Frame Sensors Plus Great Sensor Comparison Resources

My Zoom Lens Recommendations for Full Frame and Crop Frame Sensors

Remember, everything I recommend for full frame cameras can also be used on crop frame (or APS-C) sensor cameras. If you have a crop sensor camera, the APS-C recommendations below will emphasize portability and affordability while the full frame counterparts provide ultimate quality but are larger, heavier, and spendier. A few lenses I recommend in the APS-C category can also be used on full frame cameras, especially among primes since there aren’t as many crop-dedicated primes as there are primes already compatible with both. Be sure to click on the item to read more details about it before committing.

Subject Nikon APS-C Nikon Full Frame Canon APS-C Canon Full Frame
Wide – Interiors, Vistas, Crowds, Landscapes Nikon 10-24mm f/3.5-4.5G (15-36mm Equivalent)  Nikon 14-24mm f/2.8G  Canon EF-S 10-22mm f/3.5-4.5 (16-35mm Equivalent)  Canon EF 11-24mm f/4L
Normal – Events, Landscapes, Traveling, Family, Products  Nikon 17-55mm f/2.8G (25.5-82.5mm Equivalent) Nikon 24-70mm f/2.8E VR   Canon EF-S 17-55mm f/2.8 IS (27.2-88mm Equivalent)  Canon EF 24-70mm f/2.8L II
Long – Sports, Events Nikon 55-200mm f/4-5.6G ED VR II (82-300mm Equivalent) Nikon 70-200mm f/2.8G VR II Canon EF-S 55-250mm f/4-5.6 IS STM (88-400mm Equivalent)  Canon EF 70-200mm f/2.8L IS II 
Super Long – Safaris, Stadium Events, Birding Nikon 80-400mm f/4.5-5.6G VR (120-600mm Equivalent)  Nikon 200-400mm f/4G VR II  Canon EF 100-400mm f/4.5-5.6L IS II (160-640mm Equivalent)  Canon EF 200-400mm F4L IS

The benefit of using a zoom is that you get to have many lenses in 1. This is great for traveling and events where you might not have the room to carry around, or the time to change out, multiple lenses.

My Prime Lens Recommendations for Full Frame and Crop Frame Sensors

Subject Nikon APS-C Nikon Full Frame Canon APS-C Canon Full Frame
Wide – Interiors, Vistas, Crowds, Landscapes  Nikon 20mm f/1.8G (30mm Equivalent) Nikon 24mm f/1.4G  Canon EF 20mm f/2.8 (32mm Equivalent) Canon EF 14mm f/2.8L II
Normal – Events, Landscapes, Traveling, Family, Products  Nikon 35mm f/1.8G (52.5mm Equivalent)  Nikon 50mm f/1.4G Canon EF 35mm f/2.0 IS (56mm Equivalent) Canon EF 50mm f/1.2L
Long – Sports, Events  Sigma 180mm f/2.8 HSM (270mm Equivalent)  Nikon 300mm f/2.8G VR II  Canon EF 180mm f/3.5 (288mm Equivalent) Canon EF 300mm f/2.8L IS II
Super Long – Safaris, Stadium Events, Birding   Nikon 300mm f/4E VR (450mm Equivalent) Nikon 500mm f/4E VR  Canon EF 300mm f/4L IS (480mm Equivalent) Canon EF 500mm f/4L IS II

The benefit of using prime lenses is that they are designed to produce beautiful out-of-focus backgrounds when using wide apertures. They also, generally, have wider maximum apertures, which lets in more light. While you’re limited to only 1 focal length, your are forced to actually physically move your body in order to change perspective. This goes a long way toward teaching beginners some of the fundamentals of good image making.

I recommend zooms to people who plan to shoot a lot of family events, vacations, or a larger variety of subject matters. I recommend primes to people who have a stronger fine art interest, or who plan to shoot the same subjects over and over, and want to teach themselves the fundamentals of composition through restriction while still using a high quality lens.

This blog post is dedicated to all my friends and relatives who just got their first DSLR. If you’re also a beginner, I hope this helped. If you are a seasoned shooter, please share this with anybody you feel would benefit from it, along with your own lens recommendations based on your own experience.

Tags: , , , Last modified: May 22, 2020
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