Lenses and look
Posted 24 November 2005 - 03:30 AM
Posted 24 November 2005 - 11:07 AM
I couldn't find a lenses section...but my question is..what would be the 'look' difference between regular lenses, say 35 mm and 25 mm and Anamorphic? I have never used Anamorphic.
You're confusing focal lengths (25mm, 35mm, etc.) and anamorphic. The opposite of anamorphic is spherical, just like the opposite of a zoom lens is a prime lens. Anamorphic prime lenses come in focal lengths just like spherical prime lenses do. There are anamorphic zoom lenses made to.
The higher the number of focal length, the less wide of a view the lens can see. So a 35mm lens has a narrower view than a 25mm lens. Generally it's by halves and doubles, i.e. a 50mm lens has half the view of a 25mm lens. Now whether that lens looks very wide angle, slightly wide-angle, normal, or telephoto, depends on the size of the target area that its image is being projected onto.
So in a 35mm movie camera, a 25mm lens is moderately wide-angle, but on a 16mm camera, it looks more telephoto (more like how a 50mm lens looks on a 35mm camera). And on a Super-8 camera, a 25mm lens looks even longer (less of a view) than it did on the 16mm camera. So in general on smaller format cameras, the average focal lengths being used are shorter (lower in number of millimeters) than on a 35mm camera.
Now anamorphic lenses have an extra set of lens elements that give the image a horizontal compression (making things look skinny), most commonly a 2X squeeze. This allows them to fit a much wider image onto the squarish 35mm frame, only to then be unsqueezed in post or in anamorphic projection back out to a wide frame (wide as in a widescreen aspect ratio, usually around 2.35 : 1.) Because of the anamorphic lens element, the view of the lenses is doubled in the horizontal direction, so a 50mm anamorphic lens "sees" horizontally the same view as a 25mm normal (spherical) lens does, but vertically it still has the same view as a 50mm spherical lens. So anamorphic lenses "seem" more wide-angle, which means people tend to compensate by using the longer focal lengths. So whereas you might use a 20mm or 25mm lens for a wide shot in spherical 35mm photography, you'd probably use something like a 40mm anamorphic lens.
The other way of achieving a "scope" widescreen image is to just use normal spherical lenses and simply compose the frame for cropping top & bottom in post to 2.35.
Edited by David Mullen, 24 November 2005 - 11:10 AM.
Posted 27 November 2005 - 12:08 PM