My OCA Art of Photography blog: Pt 1, Ex 4. Focal Lengths

For this exercise, I selected St Peter's Chapel in Bradwell-On-Sea as the subject - more info here. I had planned to use the area for a few exercises, but once again I was greeted with awful weather and the clouds and the sea merged into one. It was also drizzling, which made for a difficult time trying to keep everything dry, something that didn't work in the 1st image as rain got on the lens.
I used 2 lenses for this exercise, a Sigma 10-20mm wide angle lens and a Sigma 50-500mm zoom. This enabled a very large range in focal length. The camera was fixed to a tripod, however as the 50-500 is such a large lens it is fixed to the tripod rather than the camera. This means that when I changed lenses, the sensor in the camera is moved backwards and downwards. This does make a small change in the resultant images, although with this subject it hardly notices. Obviously, with such a large range the differences in the images is huge, but we can see the view through the window in the centre of the images remains the same.

The original images are available in this Flick set