In digital photography, there are two main categories of cameras, determined based on sensor size: full-frame and crop sensors. And if you’ve ever picked up a camera, you’ve likely heard these terms thrown around before.
These terms are usually the starting point of the conversation and part of the puzzle in investigating a new camera. Of course, many professionals rave about the superiority of full-frame sensors. But the reality is that each has its pros and cons. And neither is superior to the other. Instead, both can meaningfully impact our photography. And there’s a compelling argument to be made on both sides.
So in this post, we’ll explain the differences between full-frame and crop sensors, cover their benefits and, ultimately, help you decide which is best for your workflow. We’ll also answer the nagging question of whether the difference of upgrading to full-frame is even worth it.
Table of Contents
Initially, we had film cameras with various sizes ranging from 35mm to 4×5, 8×10, and 120 medium format. But the 35mm format, which measures 36 x 24mm, was prized for its image quality, 1:1 reproduction, and affordability. So much so, it became a standard in the early-1930’s amongst consumer cameras, and it remains so today.
As technology progressed, we eventually saw the launch of the first Digital SLR. Early DSLRs replicated the 35mm format by using a digital image sensor with the same dimensions, 36 x 24mm. And this replication in size is what we now call the full-frame sensor, rather than 35mm film.
The idea of replicating the size was to help photographers with large caches of film lenses use their existing collection on the new digital cameras. And it thus helped them transition easily from film to digital. Without replicating the 35mm format, they’d be forced to purchase new lenses, slowing down the change and the transition.
But, as it was a new technology, it was pretty expensive and impractical for many photographers. So manufacturers gradually began making smaller sensor sizes, now known as crop sensors, to give consumers cheaper alternatives. And today, we have many different sensor sizes available.
Even so, the full-frame sensor remains the largest consumer format available. And it’s the go-to standard amongst digital imaging before moving into the more specialized medium format realm.
Main Difference: Physical Size
Ultimately, the difference between a full-frame camera and a cropped sensor one is purely the physical size of their sensors. And the differences we see in image quality characteristics, like the field of view, magnification, and depth of field, are ultimately the result of the sensor’s dimensions and its subsequent effects on capturing images. So when you hear photographers throw around the term full-frame or crop sensor, they’re really describing the camera’s physical sensor size.
But, let’s cover these differences in size now.
A full-frame sensor has dimensions of 36 x 24mm, or a close approximation like 35.6 x 23.8mm like the Sony A7 III. And like mentioned above, these dimensions replicate the 35mm film format. This also yields the 3:2 aspect ratio, which is the most used among consumer cameras.
While any camera with a sensor size smaller than 35mm (or 36 x 24mm specifically) is considered a “cropped sensor.” The most common cropped sensor formats are APS-C and Micro-Four-Thirds. The APS-C format measures around 22.5 x 15mm, also producing a 3:2 aspect ratio. While Micro-Four-Thirds measures 18 x 13.5mm, creating a 4:3 aspect ratio (hence the name). But, it’s important to note that these aren’t the only formats available. And the remaining formats do have dimensions that vary.
In the below chart, you can see the differences in size represented by changing formats.
What is a Crop Factor?
Since most film cameras used full-frame as their standard and full-frame quickly became the basis of most focal length measurements, it was essential manufacturers reference these smaller sensors in full-frame equivalent terms. And this practice is what we now refer to as the “Crop Factor.”
The “Crop Factor” or “Multiplier” is the effective focal magnification caused by using a 35mm full-frame lens on a smaller sensor. Or, put another way, it’s the measured difference or crop in the field of view that occurs. If you’re unfamiliar with that term, field of view describes how much of a scene you can capture in a photo.
And without adjusting for this difference, a cropped sensor camera with a 35mm full-frame lens crops the edges of the photo, resulting in a tighter field of view and an entirely new focal length. This magnification is due to the physics involved with how a lens focuses an image onto the sensor. So to combat this, manufacturers have made dedicated lenses for each cropped sensor camera system.
Okay. But, how does this work in the real world? Well, say a camera has a 1.5x multiplier. Attaching a 35mm F/1.8 full-frame lens causes it to act like a 52.5mm lens instead. And now, taking a photo at the same distance with the same point of view produces images with a tighter field of view than on a matching full-frame camera. This happens, as in reality, the lens behaves like a 52mm lens, not a 35mm one. And it will also produce a similar field of view, depth of field, and bokeh.
So in many ways it’s like taking a photo and only seeing 80% of the image each time since the edges aren’t ever captured. And now, viewing them on a computer makes them appear magnified or zoomed in. The thing is, by design, all cameras produce a rectangular crop in some fashion. And the full circular projection of the lens isn’t ever recorded. This is simply the rectangular design of today’s sensors. So, in reality, cropped sensors merely amplify this fact further.
But, the key takeaway here is this; if all things are equal, a full-frame sensor will always produce images with a larger field of view. And for any given focal length, smaller sensors will also capture a tighter area of the scene.
Below is a visual diagram so you can see the resulting fields of view compared to the lens’s full image projection. And I’ve also included a list of how each manufacturer tags a full-frame or cropped sensor, if applicable. And I’ve included a list of standard prime lens focal lengths and the subsequent changes from various crop factors.
** This is an image showing the entire lens projection of a full-frame lens and how each of the various sensor sizes crops that projection. The colors featured are identical to the chart above, starting with a full-frame camera and going down to a smartphone sensor. **
|Full-frame or Medium Format
How Crop Factor is Calculated
If you’re curious how camera manufacturers calculate the crop factor, it’s quite simple. The only thing you need to know is the physical dimensions of the sensor in question. From there, you’ll use the Pythagorean theorem (a² + b² = c²) to find its diagonal dimension, which you’ll then square root and divide by the known diagonal of a full-frame sensor. Now the final value from this calculation is the effective crop factor as a magnification ratio, where numbers higher than 1 cause a crop into the frame, and numbers less than 1 are larger than the full-frame.
Here’s an example of using the Sony a6300, which has an APS-C sensor.
- 35mm full-frame diagonal: 36² + 24² = 1872
- √1872 = 43.27, which is the diagonal length of a full-frame sensor.
- Sony APS-C diagonal: 23.5² + 15.6² = 795.61
- √795 = 28.21, which is the diagonal length of Sony’s a6300 sensor
- Calculate the crop factor: 43.27/28.21 = 1.53
And there’s the crop factor of Sony’s APS-C a6300 mirrorless camera, which we usually round down to 1.5x. Now, you can apply this exact principle and workflow to calculate crop factors for any digital camera, from medium format, full-frame, or a cropped sensor.
Advantages of Full-frame
Now that you know the key differences between these formats, let’s address the advantages and disadvantages of each. And let’s also discuss how they affect our photography, as the effects vary. You’ll want to pay particular attention to these differences, as this decision is something we all must contend with eventually.
Field of View
Since full-frame sensors have a focal magnification ratio of 1.0x, they don’t have a crop. And this, in turn, makes the attached lens behave true to its focal length. So a 50mm lens provides a genuine 50mm field of view. This fact is essential for those shooting wide-angle mediums like landscape, architecture, and real estate photography. In these forms of photography, you’ll frequently use a 16-35mm zoom lens. And if you have a cropped sensor camera, say a Sony a6500, it’ll effectively convert that 16-35mm into a 24-52mm, which won’t be wide enough for many scenes.
Now, some manufacturers do have dedicated 16-35mm equivalents, like Fujifilm XF10-24mm F/4. However, not all manufacturers provide a perfect match. So, for this reason alone, you may want to go full-frame.
The term dynamic range describes the amount of latitude in exposure values of an image, from the darkest shadow to the brightest highlight. And it’s something to consider if you shoot mostly outdoors, as most bright sunlit scenes have somewhere around 14 stops of difference between the shadows and highlights. Full-frame cameras, having a larger sensor with bigger pixels, can produce a higher dynamic range. Generally, most offer an effective dynamic range of 10 to 12 stops, while cropped sensors provide less.
And this lets them capture images with better detail in high contrast scenes. They’re also more forgiving if you mistake exposing the image, recovering both the shadows and blown-out highlights more effectively. And if you shoot family portraits, photojournalism, weddings, and street photography, you may want to consider getting a full-frame camera for this very reason.
Signal to Noise, High ISO, and Low-light Performance
The signal-to-noise ratio (SNR) is a function of pixel size and pixel density. Pixel size refers to an individual pixel’s physical dimensions on the sensor, and density describes their placement or packing in a given area. And the SNR is what inevitably determines a camera’s high ISO or low-light performance.
Now, being larger in physical size, full-frame sensors collect more light than a smaller sensor because it has larger individual pixels or a smaller pixel density. And this factor effectively increases its SNR compared to a cropped sensor with matching resolution. (We’re assuming both cameras have matching resolutions of 24MP for this example)
So, how this translates to the real world is this, you don’t have to increase the ISO as far when shooting in a low light scene. And, secondly, you get less visible noise at higher ISO settings, say above ISO 800., because the sensor is more sensitive to the ambient lighting. Plus, you also get a better dynamic range from this added sensitivity, improving their image quality in high contrast scenes.
Thus, getting a full-frame camera is best if you shoot night photography, weddings, or photojournalism, or mediums where low-light performance is important. And you can expect a minimum of a one-stop improvement in ISO compared to a similar APS-C camera.
Shallow Depth of Field
While the depth of field is an aspect primarily determined by the focal length and aperture of a lens, the sensor size does affect it nonetheless. And a full-frame sensor does indeed result in a more shallow depth of field when compared to a cropped sensor at an identical effective focal length. This occurs because a full-frame camera still has a longer focal length attached, altering its field of view and lens compression. And the longer the focal length, the more shallow the depth of field.
And that, in turn, yields a more pleasing blurred background and a strong artistic effect focused on your subject. So much so, it could be similar to opening the aperture several stops, say comparing full-frame to Micro-Four-Thirds. So for this reason, if you shoot portraits or weddings or want more bokeh and subject separation, full-frame is best. Otherwise, if you’re a landscape, product, or still life photographer, the added depth of field from a cropped sensor can help ensure the entire scene is in focus.
Printing Detail and Resolution
If you plan on printing images at larger sizes, say above 13×19″ or A3+, then full-frame also has a key advantage here. This is due to the different magnification ratios required to enlarge a digital image to a print. Simply put, a larger sensor requires less enlarging of the image, resulting in fewer impurities caused by artifacts and better overall detail. Additionally, if you use a high-resolution full-frame camera, you can also crop into the image without losing any meaningful detail.
And the large pixel size is part of the reason we only see high-resolution full-frame or larger cameras. It’s usually not beneficial to cram more resolution into a compact APS-C format. So if you want the best image quality for large format prints, then full-frame is best.
Being older, there are more full-frame lenses on the market than cropped lenses. And full-frame lenses, while expensive, offer professional-level image and build quality. And they usually feature more lens elements, higher-end finishes, and wider apertures. So if you want the best image or build quality possible, full-frame is best.
Disadvantages of Full-Frame
Full-frame being the long-term standard in the industry, is designed to meet the needs of professionals. And, unfortunately, many of the camera bodies and lenses reflect that intention and are substantially more expensive to suit. Many of the lenses come with a matching, and often higher, price tag of the camera body itself. And the cost of entry becomes an enormous barrier for many photographers. So if you’re on a budget, going full-frame will likely be a gradual process rather than an immediate change.
Even with the advent of small full-frame mirrorless cameras like the Sony a7, there’s no debating the fact that full-frame cameras are bulky. Sadly, the added heft and weight are mostly the result of their larger sensor and more robust design, which usually includes weather sealing. But, coupled with the added heft of most full-frame prime lenses, you can easily lug around a 5 lb camera setup. No ideal.This amount of weight will cause strain on your wrist, neck, shoulder, and hips. And the size and form factor is often the most notable complaint with this format. So, if you’re looking for something lightweight, compact, or pocketable, you may want to consider a cropped sensor instead.
Slow Frame Rate in Burst Mode
Full-frame cameras usually have slower continuous burst rates when shooting action sequences than cropped sensors. Generally, we see an average burst rate of 6-8 FPS, compared to 10-12 FPS for most cropped cameras. This occurs because their large sensor captures more data, which requires more processing time to write to the memory card. And this usually slows both the writing process and how quickly the camera clears the buffer. So, if you’re a sport, wildlife, and journalism photographer shooting events, you may want to investigate whether these speeds are sufficient.
Advantages of Cropped Sensors
Compact and Versatile
Since this format has a smaller sensor and usually lacks internal weather sealing, these cameras are almost always smaller, lighter, and more compact than their counterparts. And this difference is especially apparent if you compare mirrorless options. The result is a camera that’s more portable and easier to travel with, making them ideal for street and travel photography. So if you frequently travel, this size difference alone can be the deal-breaker and a key reason to choose this format.
Larger Depth of Field
While in some cases you’ll want a shallow depth of field, for the creative effect it provides, it’s not always a must. And rather, it’s the exact opposite for mediums like products, macro, architectural, and landscape photography, where you often want as much in focus as possible. And in comes the advantage of this format. A cropped sensor camera can offer as much as 2 stops more field depth, assuming you use a matching aperture setting and focal length. And that difference can be enough to capture a sunset at F/11 compared to F/5.6, dramatically increasing the depth of field. And this advantage alone could be a deciding factor if you frequently shoot mediums that demand higher aperture settings.
Sure, the crop factor of this format is often seen as a downside. But, you can use their magnification as a tool to give your lenses more reach. The 1.5 or 1.6x crop can transform your typical telephoto lens into a unique specialty lens that’s ideal for sports, wildlife, weddings, and photojournalism. And this fact is why both Sony and Nikon offer interchangeable lens systems, letting you use both full-frame and APS-C lenses freely.
And you can even use an APS-C mode on their full-frame bodies, giving you the freedom to use APS-C lenses without major downsides outside of a loss of resolution. Even so, you can also use this advantage as a means to avoid carrying excess lenses when traveling. And it’s a key advantage that’s ideal for wedding and journalistic photographers wanting to switch focal lengths quickly.
When factoring in the pros and cons, you’ll also want to consider the purchasing costs of these systems, including the lenses. And the difference between costs is often the first factor that photographers immediately notice. Frankly, the lower cost is a major advantage of a smaller sensor and a key reason new photographers migrate to this format.
Faster Frame Rate in Burst Mode
Since these cameras have a smaller sensor, they have less incoming data to process. And that fact results in faster average burst rates with quicker buffer clearing rates than their peers, averaging 10 FPS for most mid-range models and often unlimited RAW buffer in many cases. And for this reason, this format is often the go-to amongst photojournalists and sports photographers wanting to capture every finite movement.
Disadvantages of Crop Sensors
Now, while the crop factor is helpful to extend your lens’s telephoto power, it’s not ideal for wide-angle photography. Instead, the crop factor will magnify all images, removing much of the wide-angle effect. And it’ll make capturing architecture and landscapes quite challenging. So to compensate, you’ll want to move back further or use a wide or ultra-wide fisheye lens that matches the full-frame equivalent directly. Take, for example, Panasonic 8-18mm G lens, which matches Canon’s full-frame 16-35mm EF lens.
But, the problem is that these lenses have a lot of barrel distortion, which usually requires post-processing to fix. And not every camera manufacturer offers these options in their lineup. So if you plan on shooting landscape or architectural photography, be sure to investigate the lens selection beforehand.
Which sensor size is right for you?
Well, so which sensor format is best for me? Truthfully, only you’ll know the answer to that. This particular debate doesn’t have a clear winner. Both have their advantages. But, it’s important to highlight that most cropped sensors offer largely matching image quality these days, especially in well-lit scenes. So, a bump in image quality alone isn’t necessarily enough to make this choice. Instead, it comes down to which pros and cons are most acceptable in your eyes.
Granted, it’s also important to highlight that full-frame will continue to remain the industry standard, especially amongst working professionals. So, long-term, if that’s your goal, then it’s conceivable you’ll eventually transition that way. But, it’s also possible you’ll end up shooting a medium where full-frame offers little benefit, like sports, wildlife, and photojournalism. Either way, though, now you at least understand the pros and cons of this decision. And even though sensor size is important, the technical specifications and minutia are not the ends at all. The ultimate goal is to find a camera that inspires you and delivers on the visions you create. So whichever one does, that is the right one for you.
Frequently Asked Questions
Is full frame really better than crop?
Yes, in some situations. But, the difference is only meaningful if you want the best low light performance and widest dynamic range for your images. Otherwise, the differences are more of a personal preference, not necessarily factors that make it “better.”
Is Full Frame sharper than crop?
No. Both full-frame and crop sensors offer similar resolution and fine detail. The only means to improve their fine detail is attaching a higher quality lens, which is what mostly determines image sharpness anyways.
Is buying a full frame camera worth it?
Yes. But, it depends on the medium of photography you plan on shooting. Full-frame cameras have the biggest advantages in low-light photography, and high contrast or large dynamic range scenes. In both situations, you get better image quality due to their improved signal-to-noise ratio from the larger pixel size. Otherwise, the remaining advantages are a personal preference.
Can I use a Full Frame lens on a Crop Camera?
Yes. But both crop and full-frame cameras have unique lens ecosystems. And not every camera manufacturer uses an interchangeable mount, letting you freely switch between them. But, thankfully, Nikon and Sony offer this option. So you can use their full-frame lenses on APS-C cameras and their APS-C lenses on full-frame, assuming the camera has an APS-C crop mode. But, generally, if you intend to upgrade the full-frame long-term, it’s best to invest in full-frame lenses from the get-go. Doing so will save you money since you won’t have to replace your entire collection of crop lenses.
Last Updated on October 19, 2023 by Photography PX Published November 13, 2021