Crop sensors vs. Full-frame sensors

Today we will be talking about crop sensors, their effects, and them in relation to full-frame sensors.  First off a crop sensor is essentially a focal length multiplier, common crop sensors are 1.6x, 1.5x, and 1.3x.  I'll just use a 1.5x since it'll be easier to understand, with this crop sensor a 100mm lens has an effective focal length of 150mm lens, so you get more reach with that lens than you would with a full-frame camera or a film camera.  As a full-frame camera and film camera both take advantage of the entire lens while the crop sensors only use a centre section of the camera.  To give you a visual representation of this, here is an example.  That shows you the effect of using a crop sensor.

There are pros and cons to both however, full-frame sensors tend to have much less noise and your wideangle lenses will be much wider.  Such as an 18mm lens on a crop sensor actually becomes about 28mm, while on a full-frame camera it is actually 18mm (or the same focal length as an 11-12mm lens on a crop sensor).  The cons to a full-frame are that you don't get any help on the telephoto side, a 135mm lens on a crop camera is about equal to a 200mm lens on a full-frame camera.  Thus you can get a much longer lens a lot cheaper on a crop camera than a full frame.

Think about it like this, I can buy a 300mm ƒ/4 lens and a 1.4x teleconverter (multiplies the focal length by 1.4) for about $1300 and it will be a reasonably fast 420mm lens.  This same lens on a crop camera will be approx. 672mm equivalent lens on a full-frame camera and that is longer than a 600mm lens on a full-frame camera which costs thousands more and weighs 4 times as much.  That brings me to another point, lenses designed for a crop sensor are significantly lighter than those that are not.  This is because as you saw from the example the crop sensors only take advantage of part of the lens so the ones designed for a crop sensor don't have to have as much glass in them.

I personally prefer crop sensor cameras because for one I am not rich and the full-frame cameras are significantly more expensive (The cheapest being over $2000 new).  And second I enjoy wildlife photography and the 1.6x factor is a great benefit to me, as you saw in that lens example I gave above, well that is going to be my next investment.  I do however enjoy landscape photography and while the crop sensor hurts me there, lenses are made that will give me back that wideangle that I lost such as the Canon 10-22mm.  Anyway, that's the basics of crop sensors and full-frame sensors, and as always if you have any questions whatsoever just leave a comment or a note and I'll get back to you on it