Archived posting to the Leica Users Group, 2009/04/01

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Subject: [Leica] Full frame again!
From: lrzeitlin at optonline.net (Lawrence Zeitlin)
Date: Wed, 01 Apr 2009 16:57:41 -0400
References: <mailman.435.1238618811.976.lug@leica-users.org>

Chris' wonderful April Fool joke gave me a few seconds hope that  
Leica had finally returned to its senses. It is not impossible to  
make a full frame Leica which can use all the legacy lenses, just  
difficult. It is perhaps more of a technical tour de force than a  
financially strapped company can support.

Before the M8 was introduced I had lunch and a few beers with a  
couple of photographers who, incidentally, were optics gurus at IBM's  
Yorktown technical center. The topic of a full frame digital Leica  
came up and a number of ideas were floated to solve the problem of  
the short back focus between the lenses and the digital sensor. The  
first idea was offset prismatic micro lenses to turn the angular  
light rays in a more vertical direction, an idea Leica partially  
implemented in the M8. But this was not the only solution.

Another idea was to use an intermediate lens to capture the real full  
frame image of the prime lens and reimage it on a smaller size  
sensor. This is a common technique in instrument optics. Admittedly  
the tube length would be longer than desired and the intermediate  
field lens would have to be of the highest optical quality, but a few  
million dollars of engineering time should be able to solve both  
problems and reduce the size of the package to Leica dimensions.

A third solution was to use an optical fiber reducing bundle, full 35  
mm frame on one end, sensor size at the other. Marty Forscher used  
this method 40 years ago to produce 35 mm images from a Hassleblad.  
The bundle of fibers, each fiber smaller than a pixel, would be  
compressed on one end to the dimensions of the digital sensor. The  
compression need not be linear since software could correct any  
geometric distortion (these guys worked for IBM). Indeed, a long thin  
mechanically moved sensor could scan the bundle. An electronic  
shutter slot, so to speak. That's the way film is exposed in a  
conventional Leica.

The final solution was to keep the current format of the present  
Leica and move the digital sensor across the frame as in the previous  
example. If the sensor could move across the frame in 1/30 second, a  
digital full frame image could be recorded.  This is a miniature  
version of the old Hassleblad Leaf system. Of course there would be  
difficulties with slow speed exposures but I'm sure the Elves of  
Solms could come up with an answer.

Any other ideas?

Larry Z


Replies: Reply from henningw at archiphoto.com (Henning Wulff) ([Leica] Full frame again!)
Reply from richard.lists at gmail.com (Richard Man) ([Leica] Full frame again!)