Focal Length and Sensors

Different lenses have different focal lengths. The lens on the Cannon 600D I used is an 18mm - 55mm. The 18mm focal length would give you a wide angle shot, which you would use for images of subjects which are close to you or for landscapes. The 55mm focal length would give you a smaller angle as you are zoomed in. So you would take pictures of subjects which are far away from you. However, when taking head shots you would use a 55mm focal length because it avoids distortion. Here is my example;

 For this image I used the 18mm focal length and I had to stand very close to Amber to get all of her face to fit the whole portrait within the wide camera angle. As you can see, using an 18mm for portraits makes the persons face look wider and more distort and doesn't give you a real perspective as to what he persons face looks like. Also you can't see as much detail and the image can also look quite sharp.

For this image, I used the 55mm focal length. I was zoomed right in on Amber's face so I had to take a couple of steps back to fit her whole face in the portrait. As you can see, the face looks better than it does when using the 18mm length.This is because here is no distorion, therefore giving us a real perspective as to what she actually looks like. The overall image also looks softer and warmer as the background is out of focus, allowing us to focus on here face.






Sensor Sizes

In digital photography, the image sensor format is the shape and size of the image sensor. The image sensor format of a digital camera determines the angle of view of a particular lens when used with a particular camera. In particular, image sensors in digital SLR cameras tend to be smaller than the 24 mm × 36 mm image area of full-frame 35 mm cameras, and therefore lead to a narrower angle of view.