Lens query

[Alan Baird]

I have Olympus 40 - 150mm lens and am always reading that this is equivalent to 80 - 300 in 35mm format. How does this work and how can I get the benefit from it?

 

[Alastair]

With a crop sensor (non-fullframe as measured against a 35mm film camera) the image captured is only a part of the image projected by the lens. A larger sensor would "see" more of the projected image. The field of view seen in the image file from a small sensor is narrower, so it apears to be the equivilant of a longer lens on a full frame camera. This isn't a function of the lens, but of the sensor in the camera body.

The second question is the easy on. To get the benefit you just need to use it. Simples.

 

[John Mc]

It works out lens X sensor = 35mm size.

just means the longer the focal length on your sensor, the further you can reach.

 

[Alan Baird]

Thanks guys, now I understand