Full frame and Crop DSLRs
- Thread starter maroun.c
- Start date
Both terms describe the size of the sensor. A "full frame" sensor is the same size as one frame of 35mm film. A "crop sensor" is smaller. To keep the projected image from overlapping the sensor on a crop camera, it's slightly closer to the lens. The result is that you get some additional magnification. For example, my Rebel XT is a 1.6 crop camera. That means that a 100mm lens on my system gives me the magnification equivalent of a 160mm lens on a full frame system.
It can be quite handy if you're trying to get "closer" to a subject. The trade off is that you need to go to a very wide focal length to get a crop camera to take good wide angle shots. Many OEMs make wide angle lenses specifically for crop cameras to get around that limitation. My Tokina 12-24 is one such lens.
It can be quite handy if you're trying to get "closer" to a subject. The trade off is that you need to go to a very wide focal length to get a crop camera to take good wide angle shots. Many OEMs make wide angle lenses specifically for crop cameras to get around that limitation. My Tokina 12-24 is one such lens.
astrogazer
Premium Member
It deals with the size of the sensor incorporated into the camera system. Most DSLR's have a sensor that is physically smaller than the standard 35mm film frame. Since the sensor is smaller there is a magnification factor usually about 1.5 to 1.6, however is some PS cameras it can even be more than this. There are quite a few 'professional' DSLR's that have this 'crop' factor, as far as I'm aware there are only a handful of full chip sensors out there. basically what this does is increase the focal length of any given lens used (there are some other issues, too detailed to get into here), let's say you're using a 100mm lens on a camera with a crop factor of 1.5, the realized focal length would be 150mm (100mm x 1.5).
astrogazer
Premium Member
lol, beerguy ... you type faster than I do 
Professional is not a good description, canon has both professional full frame and consumer full frame. The 1ds mk II is a pro body, the 5d isn't. Canon also has a crop sensor in a pro body, the 1d mk II is 1.3X crop and is considered a pro body. All Nikon dslrs have a crop sensor @ 1.5X, even their pro bodies.
Frisco
Premium Member
One other important difference is the size of a pixel and the packing density of pixels on the sensor. A 10MP full frame sensor has much larger pixels compared to a 10MP cropped sensor, and that has a bit of an impact on the manufacturing complexity, the amount of gain that has to be applied to each pixel to produce the electrical signal output, and the amount of stray current/light that can inadvertantly activate a neighboring pixel (IIRC the term is 'blooming'). That is one reason that the Canon 5D full frame cam has very good noise at high ISO - the pixels are relatively huge (~10-15 microns or so) and have a pretty large collection area so they don't require as much amplification/gain to get current out, and they are located relatively far from one another and have less problems with pixel blooming relative to a similar MP cropped sensor.
