Very Crisp, and Most Important, It Feels Good In Use
The Leica 18mm f/3.8 is a terrific lens. It's very crisp, and most important, it feels good in use. It's feather weight, easy to grip and transport, feels solid, although light and exact. It seems to be another Leica landmark lens which is the very first time in more than 50 years since Leica has extended its fixed focal length lens range for their rangefinder M cameras. Up until this point their widest fixed lens available has been 21mm for the Leica M every since 1958. The 18mm is an appreciated addition after waiting for over 50 years (Leica has the 16-21mm f/4 that zooms, although it's a zoom lens, and not a fixed length lens, additionally it's not nimble with lens filters.)
Don't lose any sleep over the f/3.8 being quicker than the f/4; do the math, it adds up to less than a sixth of an f stop quicker.
The 18mm uses 77mm filters which can be used only with film, and then only if you purchase a special holder. You don't normally need filters, when shooting with digital where you'll be fine with only the dedicated hood (shich is included) sans filter holder.
Additionally Leica announced a fixed 18mm finder complementing the 18mm lens.
This 18mm lens works impeccably with all Leica M cameras that has ever been built, from the 1954 M3 through today's Leica M9. Unlike Nikon, absolutely every lens functions the same as with all Leica M lens and bodies manufactured since 1954.
(The older half-frame M8s and M8.2 discarded half the picture, therefore on the M8, the 18mm lens only provides a similar angle-of-view to a 24mm lens mounted on full-frame Leicas.)
It functions exactly the same mounted on the Leica M3 as the newer Leicas. The external finder is needed with all Leicas, so employing a1954 M3 just requires you to meter externally in place of metering through the lens. "Super-Elmarit" is only a marketing term that denotes "f/3.8."
Leica lens new updated "6-bit" coding
This Leica lens features the new updated "6-bit" coding, that allows the M digital camera to optically read this information and then identify the lens being mounted. Optionally the M camera can then apply a software based "last stage" vignetting adjustment (for images captured in RAW, the lens mounted is simply recorded, with no changes made). Apr 20, 2011
M Mount Adapters
The Leica M mount was introduced in 1954 at the same time as the Leica M3. It's been the mount of choice on every Leica M series thru the present day Leica M7 film camera and Leica M9 digital camera
The M Mount was also the mount used for Minolta's CLE rangefinder, on the Konica Hexar RF, on the later versions of the Voigtlander Bessa family
and Lenses, the mount for the Rollei 35RF, also quite recently on the newest Zeiss Ikon
Rangefinder and Lenses..
Benefits of Lens adapters is versatility, and saving money with the continued use of the preferred lenses you already own.
Drawbacks of lens adapters is the inconvenience, no electronic connection between the adapted lens and your camera body
A couple of factors are necessary for a lens adapter to work properly. First, the camera body "lens registration" space or the expanse between the mount of the lens to the sensor or film surface. Two, the "throat size" of the mount or the mount diameter. An adapter flanked by the body of the camera and a lens from different brands, this registration distance of the adapted lens must be larger than the registration distance on the body; plus the lenses throat-size must be less than the throat size on the body mount.
M lenses can be adapted to Canon EOS, Nikon, Micro Four
Thirds, and Sony Nex Cameras.