- LENS COMPARISONS -

From Alan Greeley (Area 3+)

I’ve been having a rummage through my photographic equipment drawer to see just what I haven’t used lately. Two lenses which were almost obligatory (in addition to the standard 50mm) came to hand — a wide angle and a telephoto. Yes, I was a bit of a purist in those days when they were bought and prime lenses had the edge on zooms.
Bill was crying out for articles as usual, so it seemed destined that I should see what the trio of glassware would do, and how they differed one from the other.

The wide angle was a 24mm Sunagor, the standard 50mm was the camera manufacturer’s own (Konica) and the telephoto was again one of the Sun range, this time a 135mm. The camera was a Konica FT1 which must be getting on for twenty years old, but was one of the first SLR cameras to have a built-in motor drive. Alas Konica no longer make SLRs.

Why haven’t I used them lately? Laziness probably! It seems quite a load to carry around for such an elderly white-haired old gentleman! Anyway I had a few 35mm cassettes of Tura black and white 100ASA 12 exposure films which were going out of date, so using one of these seemed just right for the lens comparison. I didn’t go far — just to the front gate as a matter of fact, but the whole point was to show the differing angle of view of each lens and the change in perspective.

The angle of view is, as you all know, the amount of the subject that is included in the picture at any given camera position. The first three pictures were all taken from the same camera position; first with the wide angle 24mm, then the 50mm and finally the 135mm. They show the considerable differences in the covering power. The 50mm, or standard lens, corresponds roughly to the human field of vision. With the 24mm lens much more of the scene is included, but everything is smaller (top photo), while the 135mm telephoto magnifies the subject and sees less of the scene (next page). The white frame on the wide angle shot will be explained later, but ignore it for now.

The following three photos are taken with the same lenses, 24mm, 50mm and 135mm. This time, however, the distance from the subject was varied considerably in order to keep as near as possible the tree on the left at the same size.

The change of distance has dramatically altered the perspective, but by using the different lenses the tree has more or less kept the same. With the wide-angle shot there is a much greater feeling of depth and objects in the background appear small and insignificant. Moving further back and using the 50mm standard lens reduces the feeling of depth and the background objects have moved closer and assumed a greater significance. The telephoto shot, taken still further back, reduces the apparent depth almost to nil and the background towers up to a dominant degree.

The bottom picture is an enlargement from the first 24mm shot (white frame area). Compared with the same 135mm shot, perspective is the same but the wide angle shot shows a greater range of focus, or depth of field.