Aperture for Depth of Field
This week I found a gem of a quote:
“When words become unclear, I shall focus with photographs. When images become inadequate, I shall be content with silence.” – Ansel Adams
Enough said! 😉
Speaking of focus… I have generally been thinking of aperture (the size of the lens opening) in terms of the amount of light that is let in when the shutter is released. However, aperture also determines how much of the picture is in focus (depth of field). (Click here and scroll down to “aperture” to see a great illustration of this.)
Depth of field has to do with the curvature of the lens and the number of angles of light that are hitting the lens. Wide aperture = more lens curve exposed = light coming in from more angles = blurriness. Clear as mud? Alternately, with a small aperture, light enters the lens in a straighter line, so more of the photo is in focus.
“When words become unclear…” it’s time for the photographs!
We had our first real snow of the season Monday, so I thought snow photos would be nice.
The first two photos were taken in “landscape” mode (turn the big camera dial to the picture of the mountain):
morning snow
Thanksgiving snow
The aperture is small, at f/14 and f/16, respectively. (Just to make things more confusing… the larger the number, the smaller the lens opening!) Everything in the above pictures is in focus, from the near branches to the far snow heaps and fence.
At the other end of the spectrum is macro mode (on the big dial, the picture of the flower). In the following picture, the snow on the back edge of my son’s cap is out of focus, as is the deck rail in the background. The aperture was open wide, at f/5.
snow capped
The following picture was my favorite of that same shoot – and the last one I took, for obvious reasons! Wide aperture of f/5.6. The tassels on her cap begin the out-of-focus range.
time for hot chocolate!
The photography/philosophy take-home? Hmmm… The more open you are to let light in, the more ONE point comes into clear focus!
I’m taking some of the “flower” focused photos to use for watercolor painting. They give the up close clarity of my subject and the perfect “watercolor wash” effect for the background. Laura showed me that setting and it is so fun. It can be reversed to focus on the background and blur the foreground as well.
It is fun! My best venture into drawing/painting was from a photo – so helpful in finding a focus and seeing what’s really there.
Your pictures keep getting better. It seems like I could reach out and touch Micaiah. The path through the photography maze seemed daunting, but you are finding your way, week by week. Even I am beginning to understand a little!