Exercise 3 - Focus at different apertures

With this exercise I should find out, what will be the focus area at different apertures with focus set in the middle of the picture. Leaving in 10 minutes driving from Baltic sea, I decided to take some shots of the row of concrete stones on the sea shore. For all three shots focus has been preset at 7m. Here are the shots I finally got:

1. The widest aperture - f/3.5; shutter speed - 1/640s.

2. The middle aperture value - f/13; shutter speed - 1/60s.

3. The smallest aperture value - f/22; shutter speed - 1/20s.

The conclusion for these three shots is that the larger is the aperture the smaller is depth of field, the smaller area of the picture stays in focus. Depending on what you want to be in focus you may use wider or smaller apertures. E.g., when taking macro pictures it is good to highlight the object more and blur the background. In these cases the big aperture might be preferred. Also, the big aperture would compensate the faster shutter speed, which is crucial when taking picture of moving object (birds, animals, insects). In this way moving object will be sharp and background blurred.