Tag Archives: Prime

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.

Panning with different shutter speeds

Hand holding and panning my camera; using my standard 50mm f/1.8 prime lens, I took a number of photos of speeding cars using different shutter speeds starting from 1/8000sec down to 2 seconds to see how the shutter speed affects the image. I set up halfway down a sloped road and from the opposite side of the road I took my photographs of the passing cars as they passed me travelling at 40 mph. I set autofocus to continues focussing; I used the shutter priority mode to automatically adjust aperture with each new shutter speed, I also had to make compensations with the exposure compensation feature and re-adjust the ISO as the shutter got towards the slowest settings I also had to add a polarizing filter to the lens in order to help shut out some of the light as I didn’t have a neutral grey “stopper” filter.

Working from the fastest shutter speed the lowest, from 1/8000sec to 1/1000sec there appears to be no sign of motion from the wheels of the cars or from background. Therefore at these settings the subjects appear to have been stationary at the moment the shot was taken as there appears to be no sign or reference to movement from any of these images. (Exposure 0 step, ISO 320)
1/8000sec @ f/2.2,
1/4000sec @ f/3.2,
1/2000 @ f/4.5,
1/1000sec @ f/6.3.
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Focal length and angle of view

My first outdoor photography exercise was to take 1 – 3 photos of a scene as seen both through the lens and the naked eye and to take 3 photos one matching my normal field of vision, one at a much wider angle to my normal field of vision and then one at a much narrower field of vision.  Having found a subject to photograph and a spot to take my photos from I set my camera up on my tripod to eye level and locked it tight so that the camera body didn’t move from its position whilst changing lenses. Continue reading