For many people who only rarely pick up a camera, a "good" photo is one where you can recognize what the subject is, such as this photograph of the Flying Kiwi blowing bubbles when he was still young and carefree.   This sort of amateur photograph acts as a reminder of a person or an event or an experience, and the pleasure of viewing it comes from the emotions which are connected with the event and brought back by seeing the photo.   The technical aspects of the photo, even whether it's focused, are secondary and might not even be noticed.

    It's obvious what's wrong with photos like this, but what's not so obvious is what's right with them.   They're a reminder that the whole purpose of photography is to create an emotional response in the viewer.   There's nothing technically special about the famous photo of marines raising the American flag on Iwo Jima during World War Two, but it's considered one of the all-time great photographs because of the emotions it stirred, and continues to stir, in the people who see it.

    Of course, if that photo was blurred then it would never have had such a strong impact, so there's a balance between technical perfection and emotional perfection.

    Unless the subject is extraordinary, a poorly taken photograph will only be enjoyed by people who experienced the event which was captured.   What's better is a photograph with enough power to arouse emotions in people who weren't around when the shot was taken.   To achieve this it's necessary to reach a basic level of competence with the camera, so that technical defects in the photo won't stand in the way of its enjoyment.

    A photo which is technically faultless might be very boring - probably most technically faultless photos are boring - but it doesn't put distractions in the path of someone looking at the shot, and some level of technical proficiency is needed before you can consistently take photographs which other people will enjoy.   In the end, however, technique is only a means to an end, and your photographs will only interest other people if you're enthusiastic about the thing you're photographing.   If you can find a different way of looking at it than most people, then your photography might even become great.

   When your eyelids are open, light enters your eye through a circular hole called the pupil and is focused by a lens onto the light sensitive retina attached to the back of the eye.

  The size of the pupil can be adjusted to allow more light to enter when the environment is dim, and less light when it's bright.   There are about 126 million sensory cells in the retina, both cone-shaped cells which are color-sensitive and rod-shaped cells which aren't color-sensitive but can detect low levels of light, useful for night vision.

    Most cameras work in the same way as the eye - when the shutter is open, light enters a roughly circular hole called the aperture and is focused by a lens onto a light sensitive medium at the back of the camera, either film or an electronic sensor.   The shutter is the equivalent of your eyelid, the aperture is the equivalent of your pupil, the lens is the same as your lens and the light sensitive medium is the equivalent of your retina.   Some types of camera, like a pinhole camera, don't have a lens, and some digital cameras don't have a shutter, but understanding how these things work will help make your photos better.
 

   The most important thing for the beginner to understand is how to control the amount of light which enters the camera and hits the light sensitive medium inside.   The amount of light determines the exposure of the photograph - whether it's too dark (under-exposed), too bright (over-exposed) or just right (well-exposed).

    Under-exposure is the most common problem for the inexperienced, and ruins more photos than any other single cause.   This often happens because we automatically assume that the camera see things just as we see them - but this isn't true.   The human eye is much more sensitive to light than either film or digital sensors.   A very ordinary room which seems to be perfectly bright often has too little light to take a properly exposed photo.   Outside there's usually about 200 or 300 times as much light as inside a room, even on a cloudy day. 

    If your photos are underexposed then there are three ways to get more light into the final photograph:
 

	(1)   Allow more light into the camera by making the aperture (pupil) larger.   The amount of light which comes through the aperture is measured in a strange unit called an f-stop, sometimes just referred to as a stop.   The larger the aperture becomes, the more light enters but the smaller the f-stop becomes.   If the aperture becomes smaller then less light enters and the f-stop gets bigger.   Every time you multiply the f-stop by the square root of two, you halve the amount of light which enters through the aperture - for instance, a camera which is set to f5.6 (f-stop 5.6) has half as much light entering as a camera set to f4 (f-stop 4).   A camera which is set to f8 has one quarter as much light entering as a camera set to f4, an increase of two f-stops.   The f-stop measurement is standard across all cameras - a Nikon-brand camera whose aperture is set to f8 lets the same amount of light enter the camera as a Canon-brand camera which is set to f8.  It's also standard whether you're using film or a digital camera - a scene on print or slide film which is properly exposed at f11 will also be properly exposed on a digital camera at f11.
	(2)   Allow more light into the camera by keeping the shutter (eyelid) open for a longer time.   If you keep the shutter open for 1/100th of a second, then you'll let twice as much light into the camera than if you keep the shutter open for 1/200th second.   However, if you're holding the camera in your hands, a slower shutter speed will result in more camera shake appearing in your picture, which makes everything as blurry as if it were out of focus.   Modern point-and-shoot digital cameras will often automatically open the shutter for a longer time if a photo is taken inside without flash, and often this causes blurred photos.
	(3)   Increase the sensitivity of the light sensitive medium (retina) by increasing its speed, measured in ISO units, which are the same as the old ASA units which some people might be familiar with.   If your photo is underexposed, then put a higher ISO film into the camera or, on a digital camera, increase the ISO rating of the sensor.   A fast film is one which records light faster than a slow film; film rated at ISO 200 is twice as fast as film rated at ISO 100.   The ISO ratings are standard across all films and all electronic sensors - an ISO 200 film gets exposed at the same rate as a digital camera sensor set to ISO 200.   The sensitivity advantage of high ISO films and sensors comes at a price:  the higher the ISO, the grainier the film becomes and the more electronic noise the sensor produces.

  Another area where problems arise because cameras differ from the human eye is in the area of contrast, which is a measure of the difference between the dark parts of a scene and the bright parts.   The human eye can easily handle a lot of contrast, but cameras cannot.   Because most people don't realize this it's easy to end up with photos where some parts are so under-exposed that they're black and other parts are so over-exposed that they're white - even if the thing you were photographing isn't white!   This can happen if you photograph someone standing in shadow with the sky behind them, or if you photograph someone standing in bright sunlight with the sun behind them.   If they're facing directly away from the sun, then their faces might be too dark while the rest of the shot is OK; if they are side-on to the sun then one side of their face might be too dark and the other side too bright.   It's often better to take the photo with them facing the sun or, even better, waiting for a cloud to pass overhead and put everything into shadow.

    One way to deal with contrast is to ensure that the sun is always behind you.   If it's directly behind you then any person you photograph will probably be squinting, and pictures of architecture or landscape might come out a bit flat and shapeless, but if the sun is behind your left or right shoulder then you'll usually have everything in your photograph bathed in roughly the same amount of light, which will minimize your problems with contrast.

    Not shooting into the sun will also eliminate any risk of flare, which refers to circles or polygons of light scattered in a line across your photo, caused by the sun or some other bright light shining directly onto the lens and creating reflections of the aperture on the glass of the lens.   Since many lenses have 5 or more separate pieces of glass inside, you can end up with many of these polygons on the photo.    Sometimes this can enhance a picture, but much more often it ruins it.

    The term composition refers to the way you place the elements of the photo in relationship to each other.   By paying attention to some simple principles of composition, you can take the first steps from taking snapshots to taking photographs which other people will think are interesting.

    The easiest thing you can do to make a photograph more interesting is to fill the frame with the subject.   This removes irrelevant distractions from the shot and forces the viewer to confront the interesting features of the thing that you've photographed.   If the person or the plane or the bird which is the subject of the shot only occupies a small percentage of the photo, it won't have much impact - a person whose feet are at the bottom of a horizontal photo and whose head is at the top will only occupy about 10% or 15% of the shot, and will have to compete for attention against 85% or 90% of irrelevant background.

    There are certain rules to follow when composing photos of different types of subject.   For instance, if you're photographing people, be nice to them; don't put a power pole through grandma's head, don't cut off the top of Aunt Selma's head, and don't cut off her feet, unless you also cut off her legs and hips!   If you're photographing a landscape or anything where the horizon is visible, make sure that the horizon is horizontal - after all, that's where the word "horizontal" comes from!   This last rule is especially true if there's a large body of water in the photo - if that picturesque sailboat looks like it's sailing uphill, then the photo isn't going to look right.   On the other hand, if it's a building or tall trees that you're photographing, make sure that vertical lines stay vertical.