Find a scene that has depth. From a fixed position, take a sequence of shots at different focal lengths without changing your viewpoint.
All images taken standing at the same spot. The only deliberate camera alteration was to the focal length however there are some slight changes to the exposure time, I assume partly due to minimal variations in the light but will also be due to the differing amounts of light reaching the sensor though the varying focal length. It was very windy and clouds were scudding over. There was also an inevitable difference to the aperture, for this set I left the aperture as wide as possible, but the maximum aperture varies with the focal length. I was curious to see how the camera would handle the long distance at this aperture, but the pictures remained sharp throughout. I assume it was because I was focused on the statue at infinity.
I then took a second set of images where there was also something (a set of bollards) in the foreground. In this case, I changed the aperture to as small as possible to maintain the widest depth of field.
In this set I was pleased to see that the depth of field remained enough to allow the bollards to be in focus even though I still had the camera focused to infinity. I was standing in a fairly shady spot, and by this point the light was changing rapidly, however I note that the camera has ‘chosen’ to vary the ISO rather than the exposure time. I assume this because the internal processor ‘judged’ that the exposure time would become too long and there would be a risk of camera shake.
Learning points:
- The focal length most similar to my eye’s view is between 24 and 34mm for my camera (Panasonic micro 4/3rds).
- Be aware of the camera changing the ISO to compensate for lighting levels, either fix the ISO in advance or use it creatively in low light situation.
- At a very small aperture with this lens I get a good depth of field although the sense of distance is partially lost, there is a much greater sense of distance in the first set of images using a wide aperture.