There's a lot of hype in photography circles about having a full-frame camera, and shooting with full-frame lenses. Sure they're marketed at professionals and can offer superior results, but is the four figure premium worth it? Let's look at some benefits, let's look at some drawbacks and let's see if a full-frame camera is actually more suited to particular genres of photography.
- Low Light Performance: The larger sensor grants the camera noticeable advantages when it comes to higher ISOs, whilst an APS-C might push out usable images up to 1600 or so, a full-frame sensor will sail up to 6400 and above. It's also important to note that the iso noise is easier to scrub in post when produced by a larger sensored camera.
- Wide Angle Options: You're probably familiar with the crop factors of APS-C cameras, and how it gives you an effective focal length above the one you might see written on your lens barrel. The 18-55mm kits often supplied with APS-C DSLRs actually clock in at 27-82.5mm*, pushing your lens out of wide territory. To get an 18mm equivalent on a crop body would requires an 12mm lens, for example. With a full-frame camera what you read on the lens is what you get, and anything below 24mm gives you the wideness you'd expect.
- Full-Frame Lenses: As a very general rule, they're just better. More expensive, yes, but sharper, better made, optically superior when it comes to minimising glare, chromatic aberration.... they're a real step ahead. Whilst you can use full-frame lenses on a crop body you're only using <50% of the projected image. This wasted image-area is doing you no favours. Another think to think about is your potential to upgrade to a full frame body in the future - buy only full-frame compatible lenses and you'll never be caught out!
- Sensor Technology: Camera companies put all their best tech into their newest, most expensive models, and so the full frame offerings are usually a generation ahead when it comes to dynamic range, ISO range and so on. Not only will you benefit from the inherent advantages that come with a larger sensor, the sensor itself will just be better.
- Better sensors live in better bodies: The cameras containing full-frame sensors are going to have more features, weather sealing, longer battery lives and so on. APS-C cameras sold to enthusiasts are stripped slightly for the less demanding market, and so won't have the same feature set you might find on full-frame models.
- Price: This is the obvious one, full-frame cameras and lenses cost a good deal more.
- You lose range: In the same way that full frame sensors grant access to wider fields of view they take off the upper range of your lenses. A 70-200mm lens on a crop body actually offers a 105-300mm effective focal length. You lose this 100mm when upgrading your sensor! For people shooting distant subjects a crop sensor can actually be advantageous for the extra reach it gives you - the 7dmii and the D500 might be better options for wildlife and sports photographers.
- Why stop at Full-Frame?: Full frame only came about as a film standard, the 35mm film was a convenient balance between size and image quality that lent itself to various uses. There are larger formats available, and these might be more suited to your needs than a full frame digital sensor. You might be surprised to hear that a lot of landscape photographers are still using large format film systems, and a lot of commercial photographers use medium format system offerings from companies such as as Phase One and Hasselblad. If you're getting a full frame camera because bigger is best, that quest doesn't end here.
- Size and weight: Bigger sensor = bigger camera. You're going to have to carry around bigger lenses too and maybe even a bigger tripod to support the extra weight. You might regret this after a long walk or a few hours hand-holding.
*Assuming a 1.5x crop ratio on a Nikon DX body.