Exercise: Focus With a Set Aperture
Find a scene with a row of subjects set at regular intervals and take 3 shots at the lens’ widest aperture focused on 1 at close range, 1 at middle distance and 1 at the end of the row.
The points chosen for each of the shots were: – Close, the white bishop, Middle, the white queen, Far the white castle.
In my opinion, of the three images above, the MIDDLE shot does not demonstrate what this exercise is trying to illustrate as clearly as the other two, because too many objects are either in, or near, focus. Of the other two, the FAR image demonstrates the concept of the exercise most clearly, whereas the CLOSE shot has more objects focused than the far. However, aesthetically, I think the MIDDLE image is better constructed as it holds more interest with the bokeh concentrating the eye to an area.
I personally don’t care for the FAR image as the bokeh tends to be an affront to the visual sense, being too much with little interest when the eye gets to the subject.
I chose the chess board to illustrate this exercise to see how my 50mm prime would handle the dof issues. The glass is fast at f/1.8 and the dof is paper-thin at that extreme. Although more than one object is focused, the dof is no more that 1″, although the optical illusion is more. What I was a amazed to see was that the dof is shown to be both horizontal and vertical around the object of attention. This is normally an intellectual concept as the usual scenes I shoot don’t have such clearly defined limits in either plane nor are they normally geometric.