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2007/8/23-27 [Consumer/Camera] UID:47739 Activity:nil |
8/23 While we're on the topic of Nikons, I'm really pissed about my new Nikkor 18-135mm lense. When I bought my Nikkor 18-135mm for only $330 I thought I was getting an awsome deal, only to find out that it has pretty much the *same* view angle as my vintage 1977 SLR with a newer Sigma 28-85mm lens. Why did they advertise it as 18-135mm when it is not? This is really misleading. Does Canon do the same thing? \_ http://www.dpreview.com/learn/?/Glossary/Optical/Focal_Length_01.htm |
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www.dpreview.com/learn/?/Glossary/Optical/Focal_Length_01.htm Focal Length By Vincent Bockaert The focal length of a lens is defined as the distance in mm from the optical center of the lens to the focal point, which is located on the sensor or film if the subject (at infinity) is "in focus". The camera lens projects part of the scene onto the film or sensor. The field of view (FOV) is determined by the angle of view from the lens out to the scene and can be measured horizontally or vertically. Larger sensors or films have wider FOVs and can capture more of the scene. The FOV associated with a focal length is usually based on the 35mm film photography, given the popularity of this format over other formats. Optical Zoom (X times zoom) and Digital Zoom Optical zoom = maximum focal lenght / minimum focal length For instance, the optical zoom of a 28-280mm zoom lens is 280mm/28mm or 10X. This means that the size of a subject projected on the film or sensor surface will be ten times larger at maximum tele (280mm) than at maximum wide angle (28mm). |