THE BARE BONES CAMERA. Assignment#1

pp. 1-43.
Topic 1. Depth of Field (DOF)

DOF is the area in front of the camera where everything looks sharp and in focus. The importance of DOF can be hardly overestimated. Control over the sharp and un-sharp parts of the image can be of considerable importance for the success.

For instance, changing DOF you can attract the viewer’s attention to the subject or hide the most important part of the frame, so that its appearance becomes unexpected and adds suspense to your sequence. Various DOF can help a lot to get rid (blur) a very busy background or to frame the main subject (e.g. photographing over somebody’s shoulder and blurring this obstacle, leading the eye of a viewer into the background where we have the main subject).

There are several factors that affect DOF:

• Focal length – the increase of the focal length decreases your DOF. Thus using a wide angle lens can help to make a greater depth of field, while a telephoto lens will give you a shallower DOF;
• Aperture – the more you close down the aperture the greater will be your DOF. E.g. DOF at f22 is much greater than at f 2.8;
• Distance to the subject - the closer you come to the subject the shallower will be your DOF.

One more thing to remember about DOF is that ‘you always have less DOF in front of your point of focus than behind it’. Thus if you want to get a greater DOF in front of your main point of focus, you should move you focus a little bit closer to the subject you want to get a greater DOF.

Here is a tutorial by Shelton Muller, that illustrates how DOF works and how it can change the look of your photos

http://bricedigitalphotography.com/?tag=importance-of-depth-of-field

And this tutorial shows how DOF works for video cameras.

http://www.youtube.com/watch?v=yMOb9Zzm_es

Some fun with the DOF. This video illustrates how changing DOF can influence your perception of the same subject.

http://www.youtube.com/watch?v=eYQOX6OZERU&feature=related

Topic 2. Lenses.

The choice of the lens can influence the look of your video a lot. So depending on your creative purposes, you should be very careful while choosing the right lens.

All lenses can be roughly divided into: ‘normal’, wide angle and telephoto lenses.

• ‘Normal’ lens is the lens is the one that helps to reproduce the objects without noticeable distortions, objects look proportionate and more or less equal to what our naked eye can see. For a video camera with 2/3’’ CCD chip, the normal lens is 25 mm

• Wide angle lens includes a larger area than the normal lens. Thus for the aforementioned video camera a wide angle lens will be e.g. 12 mm. the wider the angle the more distortion you get in your image (e.g. fisheye lenses).

• Telephoto lens includes a smaller area of the frame than a ‘normal’ lens. E.g. 100 mm lens for a video camera with 2/3’’ CCD chip.

If we take three pictures of the same subject from the same distance but with different lenses, we’ll see the following differences of wide angle and telephoto lenses comparing to a ‘normal’ lens:

• Wide angle lenses include a larger area and telephoto lenses include a smaller area than the normal lens;
• Subject is smaller in the frame with a wide angle lens and larger with a telephoto lens ;
• Wide angle lenses make elements appear farther from each other than normal. Telephoto lenses compress depth and the elements look closer than they are in reality;
• With a wide angle, when the subject goes to and from the camera, the movements seem to be faster; while with a telephoto lens they look slower than they actually are;
• With a wide angle lens camera jiggles are less noticeable and with a telephoto lens they become more obvious;
• When you shoot a face, a wide angle lens will distort (bulbous) the face features, while a telephoto lens compresses them.

Here is a wonderful video that shows the difference of the same scene shot with telephoto and wide angle lenses

http://www.youtube.com/watch?v=A0JOtBtceL8