The Effect of Camera Lenses

Wednesday, December, 7, 2011
(Pearlh Harbour Sneak Attack by Japanese on Hawaii)

The Effect of Lenses

     There are many different focal lengths of lenses. However, with the advent of the DE (Digital Era), camera manufacturers seen to have decided to make moire zoom lenses and less of the fixed focal length. A fixed focal length is one with just 1 focal length (e.g. 100mm) compared with a zoom (e.g. 20mm-135mm).

     I have both types of lenses. I prefer the "fixed" because there are less moving parts. Also, I find that the zoom gears will loosen over time, so that when I shoot towards the ground, the zoom moves by itself, and the lens goes out of focus. Also "irritant" is the fact that a zoom lens needs "breathing room" for the inside to move as you zoom in or out. AS a consequence, the escape vales (the turning ring) has a bit of space between the ring and the lens barrel.  What happens? Air is sometimes sucked in, and so is dust! I'll bet you didn't know that!

     Since my other blog is all about toys, I'm only going to show you a tabletop photo of a nice Tootsietoy Jumbo car. What I did for the 8 photos in the series below is to move the camera and item each time, so that the car "filled the frame" of the viewfinder from side-to-side. As a consequence what you should notice is:

1. The back edge of the platform that the car is on will 

change in spacial dimension (closer of farther away).

THe wider the focal length of the lens, the larger the "appearance" of a greater distance between the car and the background edge. Conversely, the longer the focal length, the shorteer the distance between the car and the background edge.

2. The car will distort from the front to the back.

Both of these "effects" are due to the relative position of the focal length (or the zoom focal length) lens to the subject. For a longer lens, the camera is farther away, but the "telescopic effect" fills the frame from a farther distance. For a shorter focal length lens, the camera has to be closer to the object than for a longer focal length lens. As a consequence, the right side of the car will, relatively speaking, be closer (by 2 inches), due to the angle that I have positioned it for. However, the camera effect is much more exaggerated.

10mm Lens

The car was about 1" (2.5 cm) form the lens.

AS a result, I had trouble with my lighting.

14mm Lens

20mm Lens

28mm Lens

35mm

70mm

100mm

135mm

In Review:

1. Shorter focal length lenses create larger exaggerated distances or spacing among objects in the viewfinder. This is known as "distortion".

2. Shorter focal length lenses, create a "compression" or shortening of the spacing among objects in the viewfinder. This is known as "compression".

3. Photographers use longer lenses to avoid distortion, and to record the actual dimensions of a product.

4. Photographers use wider-angle lenses for exaggerated effect (distortion), as well as using the wider angle in confined spaces.