Archived posting to the Leica Users Group, 2007/03/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]When the 4/3 system was first announced one of their statements was that conventional film lenses were unsuitable for digital sensors and that special lenses needed designing such that the light rays impinging on the sensor are at 90 degrees to it. This requires both a huge mount diameter and the exit pupil at infinity (impossible?). There was much discussion many years ago about this, at the same time Leica had announced that there would be no digital M camera for the same reason, the exit pupil of rangefinder wa lenses being very close to the film. It was thought that slr lenses were probably generally sufficiently telecentric to get away without designing new lenses specially for digital sensors. Clearly there is more vignetting when using RF lenses for digital than there was on film, even taking account of the offset microlenses Leica used on the M8. This seems to allow its 1.33x sensor to perform as well in this respect as the smaller 1.5x epson RD1 sensor. It seems likely that they were completely correct that a bigger sensor would have too many problems with RF lenses to bother to try to use one unless a new sensor technology arrives. History has shown that customers gets what they want, so we got the RD1 and M8, and digital cameras to take existing lenses designed for film. It is clear that there are compromises in these digital rangefinders, and, to a lesser extent, the EOS 5D and EOS 1Ds with compromised corner performance due to the lenses not being optimised for digital sensors. To what extent these compromises are acceptable to the user will be personal preference. Whether there is any long term benefit in the engineering spec of the 4/3 mount/lenses which makes the potential optical benefits overcome the sensor size disadvantage only time will tell. Frank On 8 Mar, 2007, at 07:25, Didier Ludwig wrote: > The disappointing thing is that a Digilux-3 with that Summicron is > even fatter and more expensive as a fullframe Canon 5D with 50/1.4. > I believed the 4/3 system (with a sensor in quarter-frame size) > would lead to more compact bodies and lenses, which might excuse > it's flaws like exceedingly high ISO noise and AF slowness. > Didier > > >> For me the legitimacy of the format just took a jump. >> And my wanting to be involved in it. >> Here you can see how it makes a Lumix look like a farily nicely >> balanced >> camera. As it would an Oly. >> http://dpnow.com/forum2/showthread.php?t=254 >> But they clearly need a pancake. >> A 21mm 2.8. Very thin. But leaving you not wanting more.. >> Then these 4/3 cameras will be where they need to be. >> On your person. >> Not home. >> Like a bum. >> Mark Rabiner > > > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information