What lens is that? With two, one could do stereos.
What lens is that? With two, one could do stereos.
One man's Mede is another man's Persian.
1800mm f16 Rodenstock Apo-Ronar. Used for this: http://www.immediatus.de/NINE_txt.html
In action: http://www.notizie.it/wp-content/blo...1/09/wirtz.jpg
When we say a lens is 1800mm, we mean that it requires 1800mm when focused at infinity. The exception are telephoto designs, whose optical designs allow them to require shorter bellows draw than normal. Lenses designed for SLR cameras sometimes require longer bellows draw than normal, in order to accommodate the mirror inside the camera.
For a normal lens (not retrofocus), a 1:1 photo requires 2x the infinity bellows draw. A 120mm macro lens will require 240mm at 1:1.
M = (b-f)/f
where M = magnification ratio, b = bellows extension, f = focal length
How about a 210mm lens where the magnification is around 1:3. We can calculate the required bellows draw using the following formula:
Here M = 1/3, f = 210mm, and b is unknown
1/3 = (b-210)/210
1/3 * 210 = b - 210
70 = b - 210
b = 280mm
So a 210mm lens will require 280mm of extension to make an image at 1:3 magnification.
For 1:1
1 = (b-210)/210
210 = b-210
420 = b
So a 210mm lens will require 420mm of extension to make an image at 1:1 magnification.
It looks like the lens used by Ian Ruhter here (with maybe a different FL):
http://player.vimeo.com/video/39578584
people say this lens doesn't exist but it does and it is huge.
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