The topic of full frame vs crop sensor is a debate that has surpassed most of the famous camera models. It is also an important criterion for buying DSLRs for many photographers.
Full frame cameras are costlier and traditionally bulky. They are also considered more professional and provide better results overall.
Why does the size of the sensor take center-stage in most camera debates? Is it the most important, or the only thing that matters while buying a DSLR?
What is a Full Frame Camera Sensor?
Full frame, or 35 mm sensor, as it is called, is actually the size of the film used in the SLR days. The size of the images captured with the film was 36 mm x 24 mm, and the width of the film was 35 mm, which became the common terminology.
When DSLR’s came, the same sensor size of 24mm x 36mm became standard, until the smaller sensors came, which came to be called the crop-sensor cameras.
What Is a Crop Sensor in a Camera?
Crop factor refers to the ratio of the 35mm sensor size to the crop-frame sensor. Nikon has FX and DX sensors. While FX is a full-frame sensor, DX is a crop-frame sensor. The crop factor of the DX sensor is 1.5.
The effective focal length of any lens attached to a DX body is 1.5 times the actual focal length, or focal length on an FX body. The actual reason isn’t that the crop-sensor frame has a larger reach, but the sensor can’t capture the entire image projected by the lens, and it gets “cropped”, hence appears more zoomed in.
Canon’s traditional crop-frame sensors carry a crop factor of 1.6. There are also cameras with a crop factor of 1.3 from Canon.
Micro-thirds is another crop-sensor. The smaller digital cameras carry a crop-factor of up to 5.
The Traditional Benefits of Full Frame Sensor
The Better ISO Performance
One of the biggest benefits a full frame sensor has is better ISO performance. The larger the sensor size, the better the high ISO performance. For the professional wedding, landscape, and architectural photographers – this comes in really handy.
However, modern-day crop-frame sensors show amazing high ISO or low-light shooting capabilities. The difference between the previous generation of full-frame cameras and the present generation of crop-sensor cameras has thinned owing to the advancement of technology. Sony has, in fact, brought a revolution with crop-sensor cameras, most of them being mirrorless.
Higher Dynamic Range
Dynamic Range is the difference between the darkest and the lightest portions in an image. For photographers, a high dynamic range is important to capture dynamic scenes where very bright highlight, as well as dark shadows, are present. Imagine a cloudy day with all the drama, or a white model wearing black clothes.
Dynamic range is one factor that is proportional to the sensor, while also being related to the processor. The larger the sensor size, the better the dynamic range. Hence, a more versatile camera is available. Again, in 2019, the crop-sensor cameras have gone way ahead of their predecessors in dynamic range performance. But the same technology has touched the full frame cameras too.
Combining the above two factors provides us with the real incentives of using a full frame sensor. The full frame sensors tend to provide far better image quality at higher ISOs. For example, the dynamic range of Canon 550D and Canon 5D Mark III (crop sensor and full frame respectively, released close to each other) are 11.7 and 11.6. But 5D Mark III can provide good quality images even at ISO of 3200, while 550D starts dropping drastically above 800.
Natural Depth of Field
The effective focal length in a crop-sensor is more than the original focal length. This reduces the natural gradation of focus in an image as it crops a part of the gradation while the full frame sensor gives a natural gradation. For any given lens and settings, the depth of field of a full frame lens will appear truer than the crop-frame sensor for the same reason.
Wider Focal Length
A full frame camera offers a wider focal length more easily. Lesser distortion than a crop-frame lens is another huge advantage. Let us consider the example of a 16-35 lens.
A focal length of 16mm provides great coverage for architectural shots, and for shoots in cramped spaces. On a crop-frame sensor, however, the same lens offers a widest focal length of 24mm. To get the 16mm focal length, the crop frame sensor will have to use close to 11mm natural focal length lens. But at 11 mm the lens will likely have a lot more distortion issues than a 16mm lens.
Going wider not only increases the cost of the lens but also introduces more distortion.
For most professional photographers, there’s no real alternative to a full-frame camera. They can always get a longer lens, but it is the wider lenses with less distortion that are more premium.
The Reach – Why Many Photographers Stick to Crop
For many of the hobbyist photographers, it isn’t always possible to invest in huge lenses, especially when doing wildlife and sports. The crop-sensor, although falsely, provides them with the reach they are looking for will cost them a fortune on a full frame camera.
Another advantage comes in the form of lens availability. While you cannot use crop-sensor lenses on full frame cameras (or can be used albeit with considerable loss of quality), you can use full frame lenses for the crop-sensor cameras.
Technology has also reduced the gap between the crop-sensor and full frame cameras, and some of the crop-sensor cameras provide with the quality that is barely short of full frame cameras. Also, in expert hands, a crop sensor camera can produce the same results as a full frame camera. As photographers tend to say, it is all about the glass.
Cost and Bulk of Full Frame vs Crop
The cost of full frame camera, as is obvious by its various advantages, is usually much higher than the crop-frame sensor cameras.
An entry-level full-frame DSLR is about 5-6 times costlier than an entry-level crop frame sensor camera. The bulk of the full frame DSLR is also huge and is only dwarfed in comparison to medium format and large format cameras. However, modern day full frame cameras aren’t quite as bulky, especially with DSLTs and Mirrorless cameras entering the market.
The budget is one of the bigger deciding factors in buying a camera. One can always buy a basic body and invest in better lenses instead of buying a bigger body with a kit lens.
However, it is better to buy full-frame lenses only, and keep the brand constant so that you can upgrade the body to full-frame later while keeping the lenses. Also, the bulkier body of full-frame DSLRs doesn’t go everywhere, and in some disciplines, the smaller cameras are much better.
Full frame and crop-sensor camera debate isn’t as black and white as it used to be a decade back, especially with the availability of high-end post-production, the advancement of technologies, and quality of glass attached – whatever the body may be.