Aperture is one of the two most important features of your camera. The aperture regulates how light enters the lens and how much light enters the lens. If you want to shoot truly perfect photos you need to master aperture to perfection.
Physically, the aperture is produced by a group of leaves that can be adjusted to allow either more or less light to enter your camera. These leaves can slide together reducing the aperture. The aperture determines how much light is allowed to enter the lens.
The smallest aperture value you can use is indicated on the lens.
This 18-200mm tele zoom can operate at f/3.5 at 18mm and f/5.6 at 200mm.
When the f-number is small (f/2) this is called a large lens aperture because much light is allowed to enter. If the f-number is high (f/22) the lens aperture is small because only very little light is allow through the tiny hole created by the leaves. That a high f-number equals a small lens aperture, and vice versa, can make discussing aperture somewhat confusing.
When trying to shoot a badly lit subject it is a good idea to increase your lens aperture, that is, adjust your aperture to a low f-number in order to allow more light to enter the lens. If your subject is, on the other hand, very brightly lit, it is a good idea to use a smaller lens aperture.
You generally get the best results with a circular aperture. The more leaves the aperture mechanism has the more perfect the circle of the aperture will be. For this reason the number of leaves of the lens is an important indicator of quality.
You have just been given the technical explanation of what aperture is. It may seem a little complicated, but there is, however, no reason to be alarmed. Understanding the practical ways of using aperture is much more important.
The lens aperture value is indicated in f-numbers also known as f-stops. The amount of light allowed to enter the lens is either doubled or reduced by half whenever you adjust one stop up or down the scale, e.g. twice as much light enters the lens at f/4 than at f/5.6.
f/1.8, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32
Knowing the f-stop scale and being able to change swiftly between different f-stops is very important.
The focus of this image is very precise. This very shallow depth of field is achieved by using very low f-numbers (appx. f/1.4-f/4). Shot with a 105mm macro lens.
You will most likely find the mode dial located on top of your camera housing. Depending on what model your camera is, the name of this wheel may vary slightly. Using this dial you can choose between the semi automatic modes S (on some cameras this is called T or TV) and A (or AV). These letters are different abbreviations of shutter priority mode (S) and aperture priority mode (A).
Using a wide-angle lens allows you to get a very high depth of field. Using a high f-number (e.g. f/8-f/32) you can get some really good results.
If you are interested in working creatively with aperture you should choose mode A. In this mode you adjust aperture as needed, and the camera subsequently finds a corresponding shutter speed. Alternatively, you can choose the M (manual) mode that allows you to control aperture as well as shutter speed.
Most cameras have a P (program) mode, in this mode all parameters are controlled automatically. If you really want to be in control of your camera, and consequently your photos, we recommend that you avoid using this mode.
Aperture is one of the features that you need to be able to adjust instantly, precisely, and without having to think too much. For this reason it is important to know the controls and modes of your camera before you do any serious photography. If you consult the manual of your camera you will find much more information about the possibilities of your equipment.
If you have never before used aperture as a creative tool in your photography we recommend you to start right away. You will see results in no time.
You have now learnt something about aperture, and if you have not already read about shutter speed, reading more about this topic would be the next step. Otherwise we move you on to more knowledge about focus or ISO values, both of which are important tools.
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