Exercise 3: Focus at different apertures

I found getting a suitable subject for this exercise difficult.  I tried a row of houses, railings and a fence but changes to the depth of field were not visible.  In the end I lined up a row of jars and food cans to see if I could get a result. 

The pictures below were taken at 35mm using a 18-105mm lens at apertures f4.5,f14 and f29.  The focal point was the can of vegetable curry in the middle of the line up.

Aperture f4.5
The sharpness in this shot is primarily around the can of vegetable curry with the jar and can on either side slightly blurred. 
The front can is out of focus as is the last jar in the series.
Depth of field is shallow.

Aperture f29
The line of cans in this shot are sharper from beginning to end and there is a stronger depth of field










Aperture f14
There is only a slight difference between this and f29.  The front and rear are more focussed than f4.5 and there is a greater depth of field.