>> http://groups.yahoo.com/group/elan7e/files/Ken%20Durling/0index.htm
> "Jim Davis" <[EMAIL PROTECTED]> wrote:
> First off, you're right, big difference in magnification of the
> two red roses. As to quality of other things, the 28-135 seems
> to have more contrast. I think I might shoot a couple frames
> like this on my next roll, using the 35-135 and 75-300 at,
> say 100mm.
Hi Ken and Jim,
These are the numbers for (length), maximum magnification and closest
focussing distance in Canon's Camera Museum:
http://www.canon.com/camera-museum/
For selected lenses, I calculated the [focal length] which would
produce the specified magnification and focus distances. I did this
using my lens calculator: http://members.home.net/jul.loke/ but
anyone is welcome to double-check my math...
-- LENS -- length max mag CFD focal length
EF24-85USM (0.070m) 0.16x at 0.5m [f= 59mm]
EF28-70L USM (0.118m) 0.18x at 0.5m [f= 58mm]
EF28-90USM (0.071m) 0.3x at 0.38m [f= 71mm]
EF28-105USM II (0.075m) 0.19x at 0.5m [f= 69mm]
EF28-135USM (0.097m) 0.19x at 0.5m [f= 64mm]
EF28-200USM (0.090m) 0.28x at 0.45m [f= 79mm]
EF35-80III (0.063m) 0.23x at 0.4m [f= 64mm]
EF35-135USM (0.086m) 0.15x at 0.75m [f= 86mm]
EF70-200L USM (0.193m) 0.16x at 1.5m [f=180mm]
EF75-300USM III (0.122m) 0.25x at 1.5m [f=276mm]
EF100-400L IS (0.189m) 0.2x at 1.8m [f=269mm]
So, out of this bunch of Canon lenses, the 28-90mm produces the
highest magnification by having the closest focus distance AND
by retaining its focal length at close focus.
And you can also see that the infernally focussing L zooms
are not immune from the shortening of focal length.
Cheers
Julian Loke
CC eosdoc: time to draft another table.
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