Full frame Vs. APS-C

Most photographers already know that there are two main types of camera bodies when it comes to Digital SLR cameras but here’s a little introdution anyway. First of all there’s APS-C which is a type of crop bodied camera. A crop body is where the the camera has a field of view multiplier and APS-C cameras have a crop factor of 1.6x. This means that if you’re using a lens at a focal length of say 50mm you’re actually at a focal length of 80mm. This crop factor has a few benefits and advantages and there are some lenses specially designed for crop bodies such as Canon’s EF-S range and Sigma’s DC range.

The other main type of camera body are what’s known as full frame. These full frame sensors have no focal length multiplier at all and so lenses used on these cameras do what they say on the tin! This also means that the focal lengths are identical to 35mm film SLRs. As with APS-C camera bodies there are a few advantages and disadvantages that I’ll in a moment. However the biggest difference between these two types of cameras is that full frame bodies can’t use crop body lenses. Ie: a Canon EOS 1Ds can’t use an EF-S 18-55 and those who try will often result in damaging their cameras mirror or sensor. Following me so far? Good! Because that’s the easy bit. I’ll try to cover as much as I can about the differences between these two without going OTT by covering a few things like cost, focal length conversion (already mentioned) and resolution.

1) Cost

For most semi-pro photographers who use crop camera bodies the only thing holding them back from upgrading to a full frame camera body is the cost. Full frame costs money. Often costing well over £1500 owners of a full frame camera are members of a pretty exclusive club. But don’t assume that what you pay is what you get. Obviously a Canon 1Ds Mk III or Nikon D3x is in a different league to a Canon 1000D or Nikon D40. Don’t forget that if you buy a full frame body you’ll have less money for any lenses, flashguns, filter kits and accessories. APS-C bodies on the other hand are pretty cheap. Very cheap in comparison! For the same price as a full frame body you could buy a crop body camera, a wide angle lens, telephoto lens, flashgun and a spare battery! So with regards to cost alone…APS-C is the winner!

2) Focal Length Conversion

Another well known fact about full frame bodies is that with any given lens they capture a wider view. That’s a bit of a misconception really. Full frame cameras capture a true 35mm view identical to the field of view you’d get with a 35mm film SLR with any given lens. To put it simply, full frame and flilm SLRs capture the true 35mm perspective and APS-C bodies capture a cropped version of that field of view. With APS-C only a portion of the projected image is captured by the sensor. APS-C sensors are around 1.6x smaller than a full frame sensor hence why APS-C is a 1.6x crop. To capture the focal length on a crop body camera you’d have with a full frame body to widen your zoom a bit more to match the true 35mm focal length. However on the other hand APS-C bodies are perfect for motorsport and action photographers as that crop ratio helps them capture subjets at a distance. So if landscape or architecture is your thing you’re more likely to need a full frame camera than an APS-C camera. Alternatively if you need something capable of capturing things at a distance you’re more likely to want a crop body. So really there is no outright winner! Preference depends on what you shoot.

3) Resolution

Resolution is a measure of how much detail the sensor can see…the more detail the better the image! For a higher level of detail you need a higher resolution sensor. Full frame comes into a league of its own here. Generally APS-C sensors have a much lower megapixel count in comparison to full frame for a few reasons. The first is size – because APS-C sensors are generally smaller it’s naturally harder to fit as many pixels into the sensor. In fact full frame sensors are so much larger than the light diodes an be larger resulting in better low light performane and also better sharpness…but only marginally. With smaller more tightly-packed pixels you need sharper glass to every pixel on your sensor count. If the lens you use is soft to begin with then cramming more pixels on the sensor will give you a bigger version of the same blurry image. Similarly this means that an older 12.7 MP full frame image will be sharper and be of a higher resolution than a new 15MP crop sensor. Full frame blows APS-C out of the water with regards to sharpness and resolution!

There are a few other things that affect these two sensor types as well such as ISO performance where full frame is prefered because bigger pixels mean less noise in general and depth of field issues such as background blur – at identical focal lengths, 35mm equivelant focal lengths that is, background blur with APS-C sensors will be much less because the image is effectly a wider perspective that’s been cropped. This means that background blur (aka: Bokeh) is more uniform and pleasing with full frame than APS-C. As for an overall winner it’s really up to you and your wallet! If you’re shooting motorsports, action or portraiture then you’ll probably be needing a crop body. However if you shoot landscapes, low light or architecture you’re more likely to be need a full frame sensor…if you can afford it!


About this entry