zoom question
 

General question. Lets say my GL2 with 20x lens is sitting side by side with a JVC 5000 and a 16 X lens. Both cams focus on news print at 20 feet. Which cam will record the largest print? Does the fact the lens of the JVC is physically much longer than the GL2 play a part in the equation? Thanks in advance!
Ron

The physical sizes of lens designs is not material to their optical performance, per se. Not being a "measurebator" myself I have never performed such a side-by-side comparison between my XL1S' 16x and my GL2's 20x lenses. But I'm quite confident that the 20x will produce a higher degree of magnification in the image.

You should, however, also understand that you must also consider the size and resolutions of the lenses' targets; i.e. the CCD's. You're comparing a (nominal) 1/4" target on the GL2 to a 1/2" target on the JVC camera.

Why do you ask this question?

Thanks Ken,
Just trying to get a better understanding. I did not know if the physical length of the lens played a part or not. My little part time video work may allow me to "move up" some day in equipment. I am considering the JVC 5000, but not totally convinced this is the right choice. The standard lens is 16X. The 20x cannon is several more $$$. My GL2 20x is about right for my work.
Ron

The zoom ratio of a lens is irrelevant in determining subject magnification. You need to compare the focal length of the lens in mm to determine the magnification.

Indeed. And in this regard, the GL2's 20x lens is spec'ed at a 35-mm-equivalent focal length range of 39.5mm-790mm.

When comparing digital camera focal lengths with 35mm cameras, the difference in image aspect ratio can be a factor.

Strictly one should compare angle of view (which is format independent), but some manufacturers take advantage of the 3:2 ratio of 35mm and compare horizontal field of view.

Unfortunately, few people understand or care about field of view. But almost everyone cares about how big their subject is. There is no avoiding it. Hence the need to educate people about the various factors that effect the image size of the subject, including formats, lens focal length and distance to subject.