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Heading Towards Normal

July 24, 2011


W h a t   I s   N o r m a l ?

   Not me, (or you if your still reading this). As far as focal lengths go, 50mm or so in 35mm format is considered a normal lens. This is because this focal length gives a perspective that closely matches what we see. Wide angles (less than 50mm) make things appear smaller and further away, while telephoto (greater than 50mm) make things appear larger and closer. Normal focal lengths make things appear..well normal.

   As you go from wide-angle to normal, distortion decreases (especially near the edges of the frame). If you keep your main subject the same size in the frame as you increase your focal length, you will notice that background objects will become larger in proportion to your subject as demonstrated here in a pic I stole from Wikipedia. (If you followed the link in my last post you may remember this shot).

  Red bottle stays the same as the Blue bottle grows


   If this same setup were  shot with a long telephoto, both bottles would be of equal size in the frame and, due to compression, would appear to be standing side by side. Notice that each time the focal length is increased the background seems to get closer to the subject (compression), the floor gets flatter (perspective distortion lessens), and the Red bottle gets straighter (barrel distortion lessens). The scene gets more and more normal.

 P o i n t   a n d   S h o o t e r s

   If you have a compact camera your optical zoom range is probably around 24mm to 110mm. It is worth your while to Google the specs for your model or look in the owner’s manual to find the 35mm equiv. focal length range of your camera. Armed with this info you’ll be able to select a focal length that jives with the shot you envisioned. You can then guesstimate your focal length with the little zoom amount slider on the LCD. Remember only the optical zoom matters.

E v e r y b o d y

   Instead of standing in one spot and using the zoom to get your subject a certain size in the frame, you’ll get much better results by first selecting a focal length that creates the type of shot you want, then get your subject the right size in the frame with shoe leather. Focal length has a huge effect on how your shots look, so don’t fall into the trap of selecting your focal length only as a matter of convenience (zooming in to fill the frame with your subject). Instead try to decide first what focal length would suit your intended shot (wide-angle, normal, or telephoto). Sometimes this may not be practical as your shooting positions may be restricted, but try to make this type of thinking your default.

   If all this focal length business makes you feel like you just drank a bottle of Schnapps and got on the Tilt-A-Whirl, grab the discomfort bag cause next up “Focal Review”.



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