Tag Archives: telephoto

Exercise – Focal lengths – for cameras with variable focal lengths (with a zoom or interchangeable lenses)

The object of this exercise is to appreciate the simplest effect that the changing of lenses from a short focal length to a long focal length can make with regards the amount of view taken in from these different focal lengths.  I tried to find a subject of some interest with fore and background and settled on the ruined building that I framed to the right of the overall image to give a sense of place and context.  I was lucky to have a roughly shaped triangular field of bluebells in the foreground for the long focal lengths which also added colour.  From closely examining all the photos I notice that  although the magnification changes from one photo to another the relationship of different objects doesn’t alter from one another, in this case by examining the tree in relation to the chimney in all the photos  illustrates this point very clearly.

I set my camera upon a tripod and kept the tripod in the same position for all the photos, only slightly altering the composition by repositioning the subject in the view finder.  I kept the camera setting to ISO-200 with the white balance set to auto and aperture priority set to f/8 for all the images taken and I have mentioned the different shutter speed as they automatically changed for each focal length under each picture.
I have used both primary and zoom lenses for this exercise: 24mm, 50mm, 105mm and a zoom 55-300mm DX (1.5 ratio) lens. When quoting focal lengths for images taken with the zoom lens I have quoted both the 1.5 (DX) focal length and the equivalent full frame (FX) focal length above each relevant photograph.

Prime 24mm wide angle

24mm-resizedDue to the wide angle of this lens the attached lens hood created a slight vignetting but I decided not to crop it out as I want to fully illustrate the full width of angle created from this focal length. Shutter speed 1/640.

Prime 50mm (Standard focal length)
50mm-resizedThis is the standard focal length for 35mm SLR film camera and as my camera DSLR has a full size sensor this is also the equivalent standard focal length for my camera. This means that it is approximately the same angle of view as that of the human eye. Shutter speed 1/400.

Zoom DX-55mm / FX-83mm focal length

Shutter speed 1/250.




Prime – 105mm telephoto lens

Shutter speed 1/320.




Zoom – DX80mm / FX 120mm

Shutter speed 1/200.




Zoom – DX 86mm / FX 129mm

Shutter speed 1/200.




Zoom – DX 116mm / FX 174mm
Shutter speed 1/200.




Zoom – DX 165mm / FX 247mm
Shutter speed 1/200.




Zoom – DX 220mm / FX 330mm
Shutter speed 1/200.




Zoom – DX 300mm / FX 450mm
Shutter speed 1/250.