Camera 101 – What is Aperture???

I talked about Aperture a few posts ago but I didn’t really talk about it in details. Some of you found that using A mode or Av mode to be useful and takes better pictures than Auto but you didn’t really understood why. Well, first let me give you the Princeton definition of Aperture: a device that controls amount of light admitted; a natural opening in something; an man-made opening; usually small
In short, it’s that round thing that you see inside your lens. If you look close enough, your camera actually moves it to make it smaller or bigger. The larger the aperture, the more light it takes in. The smaller the aperture, the less light it takes in. Now, look at the pictures below, one was taken at f/5.6 and the other at f/1.4. The smaller the number, the bigger the aperture gets and the bigger the number, the smaller the aperture gets….. what???? Yes, this can get confusing sometimes. You might hear someone say “wide aperture” and that means “big” aperture or the largest aperture your lens allow. For example, if you have a 18-55 f/3.5-5.6, the largest aperture that your lens will allow is f/3.5 at 18mm. Since the lens has 2 numbers, this means that your lens is not a “fixed” aperture lens. Your aperture changes depending on your focal length. Now, examine the pictures below and tell me what you see:

Taken at f/5.6
Above: Taken at aperture 5.6 or f/5.6
taken at f/1.4

Above: Taken at aperture 1.4 or f/1.4
Now that you’ve looked at the pics, you will notice that one is clearer than the other. The first picture was taken at f/5.6 and this aperture will pretty much get everything in focus, it’s still a little bit out of focus but the background is still a little bit distracting. The second picture was taken at f/1.4, at widest aperture my lens allows (50mm). The subject in the middle is completely in focus and the rest are out of focus (my focus point was in the middle). You can actually change your focus without moving your camera. If you look in your view finder, you will find several boxes (depending on camera model), some will have 3, 11, 39, 51, etc. focus points. You can move your focus points by using the arrows behind the camera. If you can’t move the focus in the view finder, you might be in “Area” mode and not in “single/dynamic” mode (refer to your camera manual).

Here’s a video that pretty much shows you how aperture works.


Comments are closed.