Lens Terminology

[Dominique Grenier]

Ok, I'll probably be flagged as a newbie for this one, but I got to ask it. I've heard a couple times now people talking about lenses and saying a 10-1 (ten to one) lens, or something like that... what does that mean exactly? I guess it must be some sort of ratio...?

Thanks.

[Mitch Gross]

It is the zoom magnification ratio. A zoom that ranges from 25mm to 250mm has a 10:1 zoom ratio. The new RED 18-85 is close to a 5:1 zoom.

Generally, wider angle zoom have a lower magnification ratio than the more telephoto models. For years the two most common zooms were the Cooke 20-100 (5:1) and the Cooke 25-250 (10:1). Of course the RED 50-150 (3:1) is an exception to this.

[Charles Angus]

10-1 means the long end is ten times the short end.

A 10-100, 40-400, 5-50 are all 10-1 zooms.

edit: got beat to the punch...

[Dominique Grenier]

Great, thank. I was assuming something like this, but I couldn't find anything for sure. Thanks again.