Depth of Field: This is a fancy way of saying how much of the photograph you want in focus. Have you seen someone with poor vision squinting? What they are doing is reducing the area through which light passes into their eyes, which in turn increases the region in which objects are in focus. (The physics of this concept is quite simple but unimportant if you just remember the cause and effect.) The analogous situation in photography is changing the aperture on your lens. This is the ‘f-stop’ on you camera.   The larger the number, the smaller the hole through which light gets in. So, to get a large area in focus (large depth of field), you can set everything in your camera on automatic and then manually set the lens to a large f-stop like f/16 or f/22. This will have the effect of placing into focus objects that are a significant distance in front and behind the object that you focused on. Conversely, using a small f-stop like f/5.6 will put into focus objects that are only a small distance in front and behind the object that you focused on (small or shallow depth of field). Usually people like to photograph landscapes with a large depth of field and small objects with a small depth of field so the object almost pops out of the image.   There are two things to keep in mind. The depth of field is also a function of the lens size (e.g. 50mm, 135mm) and the distance of the object from the camera. The closer the object, the more significantly the f-stop will affect the depth of field. When I get a new lens, I usually do a number of tests to find the depth of field relation with respect to the object distance and f-stop. It is simple to do. Place 8 soda cans in a staggered formation 8 inches apart with the first one about 6 to 12 inches from the camera lens (camera is on a tripod, of course). Focus on each can and take a photograph at each f-stop on the lens and don’t forget to write down, for each frame number, the can used for focusing and the f-stop. Looking at the photographs you can tell the effect of object location and f-stop on the depth of field.   There are a number of other ways to selectively blur part of an image by selecting a slow shutter speed when shooting moving object or following a moving object while taking the picture (panning). I will address these techniques next time and give suggest on some ways to practice them. Remember that the person in Japan is a good photographer but will never be able to take a picture as well as you can make an image. Last month I talked about Depth Of Field and I assume that all of you tried out the technique on a few roles of film in the passed month. In the depth of filed technique you can blur objects by having them out of focus. There are however a number of other ways to get things blurry. Another way to get things blurry is by having your subject move during the time that your shutter is open. I call this Motion Blurring.

Motion Blurring is when an object is moving while the shutter is open and the film is being exposed. As we all know, moving objects come out blurry when the shutter is not fast enough. We have all seen the photographs of a stream where the water is blurry and almost looks like it is moving but all the rocks and trees are tack sharp. This is done by setting the camera on a tripod and photographing the water with a slow shutter speed. I find between ½ second to 3 seconds works for me. Let the camera and the expert from Japan figure out the aperture. Another example of this method is night traffic where cars become a trail of lights. For that I can not give an exact time. I would suggest that you time a car going from one end of the camera frame to the other and doubling that time for your shutter speed. However there are some other things that can be done with this method that can have a very powerful effect on the image. For example, taking a picture of a person standing still in a crowded street, which become a blur of cars and people. This can be used as a commentary on speed, life, people and so on.

Panning is another method of selective blurring. This time it is done using the reverse of the previous method. With panning you again manually select a slow shutter speed but this time you follow the moving object with your camera. What you are trying to do is make the moving object remain stationary with respect to the camera and consequently make everything else look like it is moving.   This is by far the most difficult photographic technique for me. There are a few tricks to make it slightly easier. First, select an object that is moving at a constant speed. Next, make sure that it is moving across your line of vision, because the method will not work if the object is coming towards you or away from you. Next, put your camera on a tripod and set it up so that it will move only in the direction of the object. So if the object is moving downwards make sure that the camera can’t move right to left. This will reduce the amount of unwanted motion of the camera. Finally, try a few practice runs where you track the moving object without releasing the shutter. As with Motion Blurring, Panning will require an educated guess on the shutter speed. See how long the object will take to move across your frame if the camera is fixed and try doubling that time for your panning shutter speed.   As with any technique, when practiced and used properly, the result can be a work of art and when done by accident they are often called junk. I have found that there is a fine line between art and junk and that line, for me, is often defined by the thought that went into making the final image. To paraphrase one of my favorite sayings “One man’s Junk is another man’s Art”.