I am Jason Cher MediaTech. ;DD
Life thru lense. Yay! Anyway that is a nikon D5000.(Very Expensive)
Year 2010
1) I have to finish all my homework on time.
2) Win something in competitions.
3) Attain good result.
4) Get into CSE (SMTP)
Miscellaneous
~ This is still under maintaintence ~
Hobby
Hahas. I like photography as there is a saying,"A picture is equal to a thousand words", maybe 2 thousand. There are a lot of cameras around but I prefer Nikon DSLR as I like their lens, especially the 55-200mm lens. I hate to study but I will end up studying because I am afrail to fail. I like to eat spicy stuff, is there anyone who likes it too?
When you look at the technical specifications of a digital camera, one of the very first specification mentioned is its maximum aperture and/or its aperture range. What is 'aperture,' what is a good aperture range, and how is aperture relevant when it comes to choosing a digital camera?
What Is Aperture?
The main function of a camera lens is to collect light. The aperture of a lens is the diameter of the lens opening and is usually controlled by an iris. The larger the diameter of the aperture, the more light reaches the film / image sensor.
Aperture is expressed as F-stop, e.g. F2.8 or f/2.8. The smaller the F-stop number (or f/value), the larger the lens opening (aperture).
In practice, unless you are dealing with a fixed-aperture lens (many simple point-and-shoot cameras have only one fixed aperture), the aperture of a lens is usually expressed as a range of fstops.
A Good Aperture Range My personal preference for a 'good' aperture range is: F1.8 - F16
F1.8 F2.8 F4 F5.6 F8 F11 F16
This tells us that the camera has an aperture range of F1.8 to F16; the maximum aperture is F1.8, and the minimum aperture is F16.
There are 5 f-stops between the max and min aperture. If your camera's lens is currently set at an aperture of F5.6, closing it by 1 f-stop would mean selecting F8; opening it up by 1 f-stop would mean selecting F4.
F1.8 F2.8 F4 F5.6 F8 F11 F16
How Is A Large Maximum Aperture Relevant?
A large maximum aperture is preferable to a smaller one since it gives the photographer more latitude in the kind of pictures that can be taken.
For example, it is pretty obvious that the larger the aperture, the better your digital camera will perform in low-light situations, since a larger lens opening is able to admit more light than a smaller lens opening.
A larger max. aperture also allows you to use a faster shutter speed to freeze action. So, let's say the light meter in your digital camera calculates that for proper exposure in that indoor arena, you need an aperture of F4 and a shutter speed of 1/60 sec.
F4 1/60
To use a faster shutter speed (say, 1/250 sec.) to freeze action, you have to open up the aperture to allow more light in for that shorter amount of time.
For every shutter speed increment we go up, we need to open up a f-stop of aperture. From 1/60 sec. to 1/250 sec. there are 2 increments, so we open up the aperture by 2 f-stops, going from F4 to F1.8. Note that the camera would give proper exposure at 1/60 sec. at F4, 1/125 sec. at F2.8, and 1/250 sec. at F1.8, since all three aperture/shutter speed combinations allow the same amount of light into the camera.
Of course, in a digital camera set on Auto mode, you can select Sports scene mode, and the camera will automotically select a fast shutter speed and the appropriate aperture. Likewise, in Shutter-Priority mode, you can choose which shutter speed you want (fast or slow), and the camera will select the appropriate aperture for proper exposure.
In our example above, let's say the lens on your digital camera only opens up to a max. aperture of F2.8. If you now select 1/250 sec. (in Shutter-Priority mode), the camera will not be able to select an aperture larger than F2.8 (in our example, it really needs F1.8). It would then give you an "underexposure" warning. If you go ahead and take the picture anyway, your picture would be 1 f-stop underexposed (i.e. you really needed to open up the aperture by 1 more f-stop for correct exposure).
How Is A Small Minimum Aperture Relevant? A small minimum aperture is preferable to a larger one since it also gives the photographer more latitude in the kind of pictures that can be taken. So, let's say the light meter in your digital camera calculates that for proper exposure on a bright sunny day, you need an aperture of F8 and a shutter speed of 1/125 sec. For example, I like outdoor photography so that f stop is higher so I can up my shutter speed.
F8 1/125
Well, if you decide to use a slower shutter speed (say, 1/30 sec.), this means that you have to compensate by closing down the aperture to allow less light in.
Aperture and Depth of Field (DOF)
The Depth of Field is the distance wherein objects are in focus. There are times when you desire a great depth of field, i.e. where objects both close to you and far from you are in focus. This is especially true when you are taking a landscape picture and want as much as possible to be in crisp focus.
One way to influence DOF is by selecting the appropriate aperture. The rule of thumb is this: • Select a large aperture (or small f/value or small aperture value), e.g. f/2.8, to obtain a shallow DOF • Select a small aperture (or large f/value or large aperture value), e.g. f/8.0, to achieve great DOF
Picture on the right
Note how the use of a large aperture (small aperture value) throws the flowers in the background out of focus. Focus has to be precise.
(49.8 mm, Av, Spot, 1/30 sec., f/3.5, +0.7EV, Macro, Tripod used )
Picture on the extreme right
Using a small aperture (large aperture value) extends the DOF from the foreground all the way to the background.
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