lens questions -- crop factor and focal length question.

[Gene Sung]

Hi,

After much research, I'm thinking about getting the GH1 soon. I just have a few questions.

1) One thing that keeps getting mentioned with the GH1 is the crop factor. Does that mean that if I use my 300mm Canon FD1 lens on it, the image will be cropped on the sides? Or will there be a vignette?

2) Also, I think I read somewhere that when using 35mm lens such an FD 300m zoom, the focal length doubles. Is this true? Will the 300mm zoom become a 600mm zoom? That would be great because I loved to film surfing (which obviously requires a lot of zoom).


Thanks for any help.

 

[Cassius]

The field of view is 1/2 that of a 35mm full frame still camera. The lens length obviously does not change. The sensor is smaller than a still camera's, so the sides of the image as projected will not be seen. FD mount lenses are full frame. This means that your 300mm will have the same field of view as a 600mm on a regular still camera. Your shots will always be tighter. Which is great for wildlife work or something like surfing, not so much when you need a wide angle. The optical properties will be the same as a 300mm, because that's what the lens still is.

 

[ydgmdlu]

1) One thing that keeps getting mentioned with the GH1 is the crop factor. Does that mean that if I use my 300mm Canon FD1 lens on it, the image will be cropped on the sides? Or will there be a vignette?

"Crop factor" refers to the fact that when you use an image format smaller than full-frame, only a small portion from the center of the image circle projected by the lens will be visible to the sensor. This has the effect of narrowing the field of view. Nothing else changes.