Appature help

[Miss Moo!!]

Please could sometrying explain this in a simple way for me??

I have been told that the lower the appature no the more the background will be fussy and the lower the number the faster shutter speed you should use??

I also get fussy things at the front and in random areas??

 

[Jelster]

The larger aperture, the more light comes and the shallower the depth of field you have.

The smaller the aperture the less light comes in, and the greater the depth of field you have.

(Depth of Filed is the phrase given to the area of the image that is in focus)

The larger the aperture the smaller the "f" number.

Light at a given time & place is a constant, so if you open the aperture (widen the hole to let more light in) you need to speed up the shutter so that it lets that amount of light in for a shorter amount of time.

Does that help ?

PS: Have a look here

Steve

 

[TCR4x4]

f/2.8 will give a very thin area of focus before and after the subject. As you raise the number, the area in focus expands, so you'll have more in focus before and after the subject.

Think of it like a wall that is parallel to the sensor. At f/2.8 the wall is very thin. Everything inside with the wall will be in focus, everything outside will be out of focus. As you change the aperture to a higher number, you are making the wall thicker, so more will be in focus as whats inside the wall is thicker.


The lower the number, the bigger the hole, so the more light is hitting the sensor, so you need a faster shutter. The higher the number, the smaller the hole, so less light is able to hit the sensor, so you need a slower shutter speed to allow extra light in.

 

[String]

The perfect exposure is like a full bucket of water. The flow of water into the bucket is controlled by the aperture (how big the pipe is) and the shutter speed (how long the water is allowed to flow into the bucket).

So, using f4 and the shutter speed is 1/500, and you get a perfect exposure, you will get the same exposure if you close "the pipe" to f8 and leave the tap open longer, in this case 1/125th of a second. The difference is:

1. The smaller aperture will give you a greater depth of field
2. The slower shutter speed may cause blur if your subject is moving

Does that help you?

Dave

 

[Trig's]

http://www.apertureacademy.com/how-to-aperture.php with a little slider thingy to play with that will blur the bear

 

[phototuition]

There's an outline explanation on my blog at http://phototuition.wordpress.com/2011/01/05/apertures-and-shutter-speeds-an-explanation/

But more usefully your camera has a screen on the back that gives you instant feedback from any experiment you make with the camera settings so experimentation can play a significant part in the learning process.

 

[Miss Moo!!]

Thanks guys, i'm learning