Focal length

The focal length of a lens is a measurement in millimetres from the lens to the camera's film or CCD and is a good indication of the magnification and angle of view. When using 35mm format cameras the standard lens is 50mm. It’s called standard because it gives roughly the same magnification as the human eye, which is actually around 43mm. As 35mm format has been the standard for so long all focal lengths for digital cameras are given with the equivalent in 35mm format. See the focal lengths comparison table here

Anything longer than a standard lens is classed as a telephoto lens and magnifies the subject. Super telephotos are lenses longer than 300mm. There are times when your budget may not allow the purchase of a super long telephoto. If so there are attachments made to extand the focal length. These teleconverters are available in 1.4x, 2x and 3x magnifications and fit between the camera body and lens.

Anything shorter than 50mm is classed as wide-angle and decreases magnification, but gains a wider angle-of-view to capture more of the scene in the frame.

Ultra wide-angles are lenses wider than 21mm.

There are also special lenses, such as macros, that allow superb close up facilities and fish-eye lenses that have a 180 degree angle-of-view and produce circular images.

In most cases the physical size of a lens is relative to the focal length, a 400mm lens will be longer than a 28mm lens for example. One exception to this is a mirror or reflex lens, so called because it has a set of mirrors inside the lens to fold the light, making the lens about half as long as a conventional telephoto.

By: bill451 2762 days ago
What type of lens would be best for up close action for soccer games? I currently use a 70mm-300mm but it's hard to get a close up shots - they players seem rather distant
By: Midget34 2337 days ago
I'm having this same problem with shooting youth football, soccer and baseball. I've done a lot of research on whether or not to buy a 400mm telephoto lens or a zoom lens. According to my WONDERFUL photographer crew at my camera shop, the best answer for these youth sports issues is the Nikon 200mm-400mm Zoom f4 VR SLR. It's pricey at 5G, but if you do this for a living, this it's well worth the price. I've tested one out, and it's GREAT! (Also, make sure you use a monopod if you don't already, it's quite heavy). As for me....I'm still saving the dollars to try and have one within the month....

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