After a long time without posting, here I am back! Sorry for the delay, but life got quite hectic.
Did you knew that its quite possible that your camera has a crop sensor and not a full frame one? What that means, it means that a lot of the DSLR cameras that are in the market today have a smaller sensor than the traditional film camera. In general for normal hobby photography having full sensor or a cropped one won’t really change your pictures, but its good to know so when you do your pictures you understand what its going on in your camera.
Film cameras have a 35 mm sensor, this is the size of the negative and the sensor means the long side of the negative that is exposed to light to make the picture. After that digital cameras took that concept as full frame, so a full frame is a 35 mm sensor in the digital world is the same concept as in the film time, but instead of having film there is some special material that is sensible to light, so when it exposed to light it captures the picture.So what is cropped sensor? Well its a smaller sensor than 35 mm. Most of the cheap and non professional DSLR have a cropped sensor, the size of the sensor depends on the camera and the model of it, you can find it in the internet. So this means that the area where the picture will be exposed is smaller than in the full sensor.
Full frame has usually more advantages, like better quality pictures and its possible to work with higher ISO, but usually the cameras are bigger and more expensive than the cropped sensor ones.
One of the things to take into consideration with the cropped sensors is that the focal length of your lens is not what it says in the box. What this means? This means that for example you have a lens that says 50mm in the box and a Canon 600D, this camera has a cropped sensor so the 50mm in your camera will be like a 80 mm in a full frame camera. Just to know that will help you to make the right decision when buying a lens. There are a lot of calculators around that will help you to know which lenses you have, for example this one: http://www.digified.net/focallength/
Some examples if you have a Canon 1.6x cropped sensor:
|Lens focal lenth||With cropped sensor 1.6|
If you are interested in a more techicall and detailed explanation, check this page.