Let me thank all of those who appreciated myfirst post about camera basics. Here comes the second one. Remember, this short course can give you a fair idea and some useful information about cameras and their use. However, you cannot start taking wonderful pictures without spending some tme. The learning curve in this field is not that complicated or steep. Yet, it definately asks for time!
Camera Basics : The Aperture
The aperture is the opening light enters the camera through, and on most cameras a iris allows you adjust its size. Widening the opening allows more light to contact the film, so it and the shutter affect your exposure time. The aperture also affects the depth of field, or the area that is in sharp focus from the closest in focus element to the farthest. As the aperture size decreases, the depth of field increases as out of focus elements are less noticeable when the lens area is reduced.
When you adjust the aperture size, each click either doubles or halves its current size. The aperture uses a system of f-numbers in a standard order. The larger the number, the smaller the opening. Depth of field for a long lense is much narrower than for a shorter one. As decreasing the size of the aperture reduces the amount of light entering the lens, it can make it a little more difficult to focus, so most cameras keep the aperture open until you click the shutter. Most cameras come with a preview button that closes the aperture down to whatever setting you’re using, letting you see how sharp it really is.
Camera Basics : Films
One of the most important factors to consider when selecting your film type, is its speed or sensitivity to light. High speed films are very sensitive and so require little light, allowing you to select a lower aperture or shutter setting even in lowlight conditions if necessary. The downside to using high speed films is that the grains on the film have to fairly large so they’ll react quickly enough, which can severely hinder image quality should the image be blown up. Low speed films require a great deal of light to function properly, but because the grains are smaller it can render fine details. The downside to slower films is if there isn’t quite enough light, you may have to use a slower shutter or wider aperture setting. Overall, high speed films are for lowlight or action scenes, and slow films are good for static subjects that have a lot of detail you want to bring out.
There are two standards for measuring film speed, ASA (American Standards Association) and DIN (Deutsche Industrie Norm). They are usually displayed together via ISO (International Standards Organization) as follows: ISO 100/21. Any increase or decrease in the numbers is proportional to the increase or decrease in film speed, if you choose one film that’s number is twice as high as another it is twice as fast. Each doubling or halving increases or decreases the required exposure by one full setting, on the aperture or shutter, so keep that in mind.
Many prefer black and white film to color because of its ability to enhance the dramatic. Its simplicity allows it to convey moods and contrasts far easier than color, which sometimes complicates the image overly much. Black and white is also far easier to develop and print at home and the equipment isn’t terribly expensive or complicated. It is also available in a far wider range of speeds, from ISO 32 to ISO 1250.
If you’re going to use color film, you also need to decide whether you want prints or slides. Prints are made from a negative and are printed out on special sheets of paper. Slides are made into small transparent films that are placed in cardboard mounts and viewed via a projector and screen.
Prints are the most popular because of the convenience with which they may be viewed, such as in an album or frame. Also, prints are easier to manipulate during development to remove unwanted flaws or distortions.Slides maintain greater color quality and are better for use in magazines or other reproductions. It is also far easier to “enlarge” a slide by simply projecting a larger image allowing you to recreate a scene more accurately.
It is easier to judge the quality of a slide, so some people take their pictures on slides initially then have their favorite images carried or to prints. Slides cannot be adjusted but very little during processing, so great care must be taken during the initial exposure. If you use daylight slide film in an area that has artificial lights, you may see false colors on the finished product. Fortunately, there are films specially created to compensate for this that work with standard tungsten photographic lights and common house light bulbs.
I hope you have enjoyed this lesson on camera basics.