Archived posting to the Leica Users Group, 2009/12/19
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Dec 19, 2009, at 9:17 AM, Frank Dernie wrote: > Hi Steve, > the limiting factor in whether a lens "matches" the M9 offset microlenses > and IR filter is the position of its exit pupil which, if I understand > correctly, is a virtual point from which the image can be considered to be > projected onto the sensor. It has been argued, strongly by Olympus in > early digital days, that only lenses designed specially for digital, with > exit pupil at infinity, were suited to digital sensors. Long lenses > approximate to this anyway and clearly this is an exaggeration since it > seems any wide angle lens designed for a reflex camera has a sufficiently > distant exit pupil by the time it has been designed to miss the mirror. WA > lenses for rangefinder cameras have their exit pupil much closer to the > sensor, because they can, and for film this was no problem, coming up with > a compromise which suits the M9 to the Leica lenses is what the offset > microlenses etc are all about. I am sure the design of the M9 and its > software are a good match for the 21mm f2.8 asph. > The 21mm f4.5 Zeiss lens OTOH is almost symmetrical, was designed for > film without taking these precautions and has very low distortion as a > result, but making it unsuited to the digital sensor. > I am sure Leica lenses work fine with the M9, with the exception of those > published in their literature. > Making the offset more would start to make the M9 unsuited to the longer > lenses... > Some of the Zeiss and Voigtlander Leica mount lenses are unsuited to the > M9 but at the beginning Zeiss did not say so. AFAIK nor did Voigtlander. very interesting and totally clear Frank, even to me...thank you, Steve > cheers, > Frank > On 19 Dec, 2009, at 16:51, Steve Barbour wrote: > >> >> On Dec 19, 2009, at 2:46 AM, Frank Dernie wrote: >> >>> My WATE works fine on the M9. I always assume a lens with an exit pupil >>> extremely close to the sensor will be too extreme to be compensated, so >>> the 15mm CV almost certainly won't work, though I took a few shots with >>> my 12mm and it seems not bad, I preferred uncorrected. Depending on the >>> subject the shortcomings may not be noticed at all. It was pretty >>> obvious that the Zeiss 21mm f4.5 would be unsuitable for digital >> >> I'm sorry Frank, I don't follow... why is that and does it apply to the >> Leica 21/2.8 Elmarit ASPH on the M9....? >> >> Does that apply to use with the appropriate external viewfinder? >> >> >> >> thanks, Steve > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information