Full-size Sensor On DSLR Camera Has Advantages2009-06-14 22:48 | Source
- 1.7x - Sigma SD14, Sigma SD10, Sigma SD9
- 1.6x - Canon EOS 500D, 50D, 1000D, 40D, 400D, 30D, 450D, 20Da, 350D, 20D, 300D, 10D
- 1.53x - Pentax K10D, Pentax K200D
- 1.54x - Pentax K20D
- 1.5x - all Nikon DSLR cameras (except the full-frame D3, D3x and D700); all Fuji; all Sony (except full frame A900), and all Konica Minolta DSLRs.
- 1.3x - Canon EOS-1D Mark III, 1D Mark II (and Mark II N)
The size of the sensor inside a camera determines the field of view that will be expressed in each photograph. Most of the lenses used on DSLR camera bodies cast a light circle intended to cover a full frame sensor/35mm negative. Since a cropped sensor is smaller than a 35mm negative, it captures a smaller portion of the area covered by a full-frame sensor. Cropped sensors also have an effect on depth of field - they increase depth. The difference is not overly dramatic when comparing a full-frame sensor to a size such as APS-C or Nikon's DX format (which appears in cameras such as the D5000, D90 and D300). However if you were to compare the depth of field produced by a DSLR to that of a point & shoot camera, the difference would be quite pronounced. While taking a portrait at f/2.8 with a DSLR would give you a nice blurry, out-of-focus background, f/2.8 on a compact digital camera would put much more of the scene in-focus. The sensors in pocket-sized compact digital cameras are but a fraction of the size of those found in DSLRs, therefore differences in depth of field are very noticeable.
Another major advantage of full-frame sensor is the use of wide angle lenses. Given the crop factor of small sensor DSLRs, wide angle lenses lose their characteristic wide angle of view, for example, a 24mm lens on a small sensor camera with a crop factor of 1.5 takes on the optical characteristics of a 36mm lens. When used on full-frame DSLR, the lens will continue to behave like a 24mm lens offering the same angle of view like a 35mm film camera. In addition to wide-angle photography, the larger full-frame sensor allows for larger pixels on the sensor that provide wider dynamic range and lower noise at high ISO levels. As a consequence, full-frame DSLRs may produce better quality images in certain high contrast or low light situations.
Here is a recent Q&A from San Francisco Chronicle answering a reader question on whether he should go with a full-size sensor for the DSLR camera purchase:
"Q: I'm in the market for a DSLR camera, and I can't decide whether to go for one with a full-size sensor. They're about $2,000 more than models with the smaller APS-C/DX sensors. What makes a larger sensor better, and why the big price difference?
A: On a full-size sensor, the individual pixels are larger so they can gather more light. That produces more-detailed photos and better images in low light conditions. Photos taken with a full-size sensor can be blown up larger without losing quality.
Also, full-size sensors take full advantage of 35mm lenses, so you don't have to worry about the "crop factor" inherent with smaller sensors. That's most important for wide-angle shots, because a smaller sensor will reduce the angle of a lens.
So why do full-size cameras cost more? Because they're physically bigger than small-sensor cameras, and the larger sensors themselves cost more to manufacture (although I doubt it's $2,000 more).
There's also another reason. If Nikon and Canon put full-size sensors in their consumer DSLRs - which boast many professional features as it is - they'd cannibalize sales of the more expensive models."