Exercise – Focal Length and Angle of View

The initial exercises of the course set out to get one used to the camera and its operation. The first of these is to do with the lens and particularly the effect of focal length on field of view.

I am lucky enough to have a selection of lenses, both prime (fixed) and zoom and can cover a range from 17mm to 200mm. My camera is full frame, meaning a 36x24mm sensor (the same size as the exposed area of 35mm film) as opposed to a crop sensor. In turn, this means that the focal length marked on the lens is the actual value. A crop sensor camera uses a smaller sensor and so only the central area of the equivalent full-frame image that effectively zooms the image by 1.6x, cropping the edges.

Anyway, I stopped off on my ride home from work to take these pictures of a local landmark. Old John is a folly, built in the late 1700s and a well known landmark in Leicestershire. I am almost embarrassed to include photos of such a tourist attraction in my coursework. Anyway, after lugging my camera and lenses to this spot, it took the very average pictures you see here. To keep the same view each time, and without using a tripod, I used the left hand focus point and focused at the base of the tree in the hedgerow to the left of the frame.

Standing in the same spot, I took pictures at 17, 40, 50 and 200mm. The reason for the 2 at the similar focal lengths of 40 and 50mm was to explore the idea of the ‘standard’ length. Digital cameras magnify the view through the viewfinder slightly, so the exercise in the notes that described fitting your standard lens and using one eye to look at the scene and the other through the camera is something I’ll try on a film camera at a later date.

Old John Set Up

The next step was to print the pictures and return to the same spot, working out how far away the picture had to be to match the scene. I did this on my way home from work, again on my bike. Problem was that it threw it down on my way to work and my printed pictures were soaked and became one damp mass. I peeled them apart and began holding them up to compare to the scene.

The image shot at 17mm had to be held closer than it was possible to focus, 2 inches or less. I had to wrap the paper around my face to duplicate the scene at the same size. When I took the paper away from my face, a couple walking their dog were looking my way in a pitying manner.

40mm needed to be held around 8-9 inches from my eyes. The shape of the gate, particularly the gate posts being close to the edge of the page, allowed me to match the scene easily.

50mm was about 4 inches further away and a much more comfortable viewing distance.

As I was on my own, with floppy sheets of A4, I struggled to get the 200mm print at the correct distance. I ended up hanging it in a thorn bush around 3m away.

This was an interesting exercise and taught me a couple of things, although more about the course than the camera. The main learning point was to simplify the logistics of my exercises, otherwise the course may take the rest of my life. Carting around the camera and lenses on a bike was daft. The idea was that it would fit into my lifestyle and save me making an extra trip. It did that, but also gave me back-ache.

The second point is to take better pictures for the exercises. Those attached are rubbish. They achieved the point of the exercise, but I’m a Photography Degree student who should be doing better than this!

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