Question on Rangefinder Lens Focal Length

[V0IGTLANDER]

Hi Range Finder Gurus

I am new to rangefinders, being a SLR user. I am planning to get a Bessa R3A with some lens online. Unfortunately I am unable to get hold of any lens to try out before the purchase. I would like to know what is the RF-equivalent of a SLR's 17mm and 85mm lenses. Or is there no difference?

Thanks.

 

[doubs43]

Hi Range Finder Gurus
I am new to rangefinders, being a SLR user. I am planning to get a Bessa R3A with some lens online. Unfortunately I am unable to get hold of any lens to try out before the purchase. I would like to know what is the RF-equivalent of a SLR's 17mm and 85mm lenses. Or is there no difference? Thanks.

They are essentially the same except for the manner in which the lens are designed for the specific type of camera they are to be used on. i.e.; An 85mm lens for an SLR will be the same as an 85mm for a RF. Their mounts, of course, will be designed differently but their images on film will be the same.

Walker

 

[Doug]

Yes, it is the size of the sensitive material that determines what is a "normal" lens angle of view. All recent 35mm cameras have a film gate 24mm x 36mm in size, regardless of the viewing method, ie, SLR vs RF. Digital cameras with interchangeable lenses have a sensor that is about half this area, and a "645" roll-film medium format cameras' film gate is about 42mm x 56mm... and so on for many different film and sensor sizes. By convention, a "normal" lens focal length is about equal to the diagonal of the sensitive area.