Monday evening aperture

Monday January 31, 2011

Okay...so I mentioned aperture a little bit in my last entry and how it works together with ISO and shutter speed. I also mentioned that aperture effects depth of field. Well, here's a little more on that.

Recap: aperture is the size of the opening in the lens when you take the pic. Aperture is measured in "f-stops". The super confusing thing is that the smaller the f-stop #, the larger the aperture (the bigger the opening, the more light that is allowed in, etc.) So, f 2.8 means more light than f 7.8.

So, moving on to aperture and depth of field. Depth of field is the amount of your picture that shows up in focus. For landscapes, you want a large depth of field- meaning that everything in your picture (foreground, middle ground, background) is in focus. BUT, for portraits you may want a smaller depth of field so only the subject is in focus and the rest of the background is kind of blurred...this helps add emphasis to your subject. Get it?

But how does aperture effect depth of field, you ask. Basically, like this- the larger the aperture (the more light allowed in, the smaller the f/stop #), the smaller the depth of field. It's easiest to remember it by small f/stop #= small depth of field. With larger apertures/smaller f/stop #s, less of your shot is in focus.

For example:

The pictures below were taken with larger aperture (f/5.6) and you can see that only the subject that I focused on is clear, the rest is a bit blurred. When I focus on the glass, the puzzle in the background is blurred. But, when I focus on the puzzle, the glass in the foreground is blurred.





Neat huh? Obviously, the blur would be a little more dramatic at smaller f stops, but for some reason, 5.6 is as small as my camera would let me go (probably adjusting for lighting). I think the pics show the general gist though....

On the flip side, if you have a small aperture (larger f/stop #), then the larger your depth of field and the more of your picture is in sharp focus.

So, there's your mini lesson on aperture. How fun is this? Pretty exciting, I know :)

Next up, I'll have to start playing around with ISO. Get excited....:)