Depth Of Field Experiment


Jan bought me a book for Christmas called “Understanding Exposure” and I’ve been dying to try out some of the exercises.

Yesterday was warm enough to spend some time working on depth of field.  Basically, the smaller the aperture, the greater the depth captured. (click on any picture to see a larger version)

Shallow Depth Of Field

This first shot was taken using a setting of F/4.5 for 1/1000 of a  second.  The lens is wide open (the smaller the f number, the larger the aperture).  No, I don’t understand it either.

The foreground is crisp and clear while the background is very out of focus.  This naturally leads the eye to the tap itself. 

An automatic digital camera sees this shot and automatically tries to bring everything into focus so it chooses a smaller (larger number..huh?) aperture and a longer exposure. 

Deep Depth Of FieldThis shot was taken at f/22 for 1/40 of a second and approximates what an automatic camera would capture.

In an effort to avoid capturing what it feels would be a bad exposure (out of focus elements), a smaller opening is used and gathers more light by increasing the exposure time.

It’s still an OK picture but now your eye isn’t really sure where to look as the trees in the background compete with the tap for your interest.

This is really the first time I’ve been really able to demonstrate the power of a digital SLR being used with manual settings.  If I’d set the camera to automatic mode, I would have naturally got the second shot.  I prefer the first one.

One last one.  In this one, I manually focused about 10 inches out so that the middleground was highlighted.  The picnic table board in the foreground is out of focus  as are all the other tables in the background.  Only the second board is clear and your eye is drawn to the knot.  If I had really thought about this composition, I would have made sure that you couldn’t see the tree in the far background.  The angular, dark trunk competes with the effect I was trying to achieve. (f/4.5 1/1250 sec.)

Heart Lake

I could crop it to get rid of the tree which works better but now it’s a flat shot.


Still lots to learn.