matts13
December 9th, 2009, 06:32 AM
I'm no photography expert or anything, but I noticed there was no info here about different functions and whatnot of cameras. Sorry if this gets too technical or boring. This is mostly aimed at more advanced SLR cameras, where there may be some confusing functions.
Aperture
This is the amount of light that the lens lets into the camera. A aperture (now this is quite confusing) which has a small hole has a larger f value and a wider "depth of field" which is how wide the area of things in focus is.
In other words, with a f value of 22, the subject and background will be in focus, however with a f value of 3.5, only the subject will be in focus and the rest will be blurred. A bigger f value means a smaller hole, and so less light gets into the camera, which means you have to either have a longer exposure (see later) or a higher ISO sensitivity (see later) else your photo will come out too dark.
You can use the 'Av' function on a camera which lets you set the aperture and the camera will control the rest.
Exposure
This is how long the sensor (or film) is exposed to light through the camera. It is measured in seconds (mostly fractions of a second) like 1/80 (one eightieth of a second) or just 80 sometimes. A longer exposure means more light gets to the sensor (or film) but there may be some motion blur (which can be used artistically, for example with fireworks). You can use the Tv or Sv function on your camera to set the exposure time and let the camera deal with the rest. My camera goes from 1/4000th of a second to a 30 second exposure.
ISO sensitivity
In the old days of film you used to get different types of film that were made differently. A higher ISO film has more sensitivity but has weird dots of colour all over called 'noise'. I'm sure you've seen this on some pictures taken with a cellphone camera especially at night. Personally, I don't think high ISO's are any good cause they degrade the quality of the picture, but sometimes you are forced to use it because there's just not enough light. dpreview.com says it well:
"The lower the sensitivity, the finer the grain, but more light is needed. This is excellent for outdoor photography, but for low-light conditions or action photography (where fast shutter speeds are needed), more sensitive or "fast" film is used which is more "grainy". "
Today, digital sensors can be set to an ISO "speed" (you don't have to buy a different sensor ;) ) which ramps up the sensitivity. 200 is a low ISO, 6400 is too high to win any awards, unless its supposed to look old fashioned or something, but rather do that in photoshop.
White balance
With our eyes, if we look at a light bulb (please don't, its bad for you), it looks pretty white, right?
Most lights give off light with some colour. The colour given off by a light is called colour temperature, the unit is Kelvin (K).
A high colour temperature is a blue-er light, and a low colour temperature is a yellowish white.
Tungsten bulbs (the round ones that get hot) give of a low colour temperature (around 3000K), which makes the photo look 'warm'. CFLs (energy savers or flurescent bulbs) normally give off slightly blue colour, although you get many kinds which give off different colours. 'warm white' has
a yellow colour and 'Daylight' ones have a blueish colour.
Colour balance helps to correct the colours so that whites look white and not some other colour. This is usually done on a computer. Find something white in the photo and correct the colour using the right tool. You can also take a photo of a blank piece of white paper just before taking the actual picture you are wanting. Adjust the picture of the paper until the paper looks properly white, then adjust the other picture exactly the same.
I hope this has helped you understand some of this stuff better, and that you can use this stuff to
take even better pictures. I'll post some photo ideas I've found if you're interested.
Aperture
This is the amount of light that the lens lets into the camera. A aperture (now this is quite confusing) which has a small hole has a larger f value and a wider "depth of field" which is how wide the area of things in focus is.
In other words, with a f value of 22, the subject and background will be in focus, however with a f value of 3.5, only the subject will be in focus and the rest will be blurred. A bigger f value means a smaller hole, and so less light gets into the camera, which means you have to either have a longer exposure (see later) or a higher ISO sensitivity (see later) else your photo will come out too dark.
You can use the 'Av' function on a camera which lets you set the aperture and the camera will control the rest.
Exposure
This is how long the sensor (or film) is exposed to light through the camera. It is measured in seconds (mostly fractions of a second) like 1/80 (one eightieth of a second) or just 80 sometimes. A longer exposure means more light gets to the sensor (or film) but there may be some motion blur (which can be used artistically, for example with fireworks). You can use the Tv or Sv function on your camera to set the exposure time and let the camera deal with the rest. My camera goes from 1/4000th of a second to a 30 second exposure.
ISO sensitivity
In the old days of film you used to get different types of film that were made differently. A higher ISO film has more sensitivity but has weird dots of colour all over called 'noise'. I'm sure you've seen this on some pictures taken with a cellphone camera especially at night. Personally, I don't think high ISO's are any good cause they degrade the quality of the picture, but sometimes you are forced to use it because there's just not enough light. dpreview.com says it well:
"The lower the sensitivity, the finer the grain, but more light is needed. This is excellent for outdoor photography, but for low-light conditions or action photography (where fast shutter speeds are needed), more sensitive or "fast" film is used which is more "grainy". "
Today, digital sensors can be set to an ISO "speed" (you don't have to buy a different sensor ;) ) which ramps up the sensitivity. 200 is a low ISO, 6400 is too high to win any awards, unless its supposed to look old fashioned or something, but rather do that in photoshop.
White balance
With our eyes, if we look at a light bulb (please don't, its bad for you), it looks pretty white, right?
Most lights give off light with some colour. The colour given off by a light is called colour temperature, the unit is Kelvin (K).
A high colour temperature is a blue-er light, and a low colour temperature is a yellowish white.
Tungsten bulbs (the round ones that get hot) give of a low colour temperature (around 3000K), which makes the photo look 'warm'. CFLs (energy savers or flurescent bulbs) normally give off slightly blue colour, although you get many kinds which give off different colours. 'warm white' has
a yellow colour and 'Daylight' ones have a blueish colour.
Colour balance helps to correct the colours so that whites look white and not some other colour. This is usually done on a computer. Find something white in the photo and correct the colour using the right tool. You can also take a photo of a blank piece of white paper just before taking the actual picture you are wanting. Adjust the picture of the paper until the paper looks properly white, then adjust the other picture exactly the same.
I hope this has helped you understand some of this stuff better, and that you can use this stuff to
take even better pictures. I'll post some photo ideas I've found if you're interested.