A first for Leica can be seen in two ways... as either a catching up with the rest of the industry after many years of extra and thoughtful R&D or an innovation that the rest of the industry might just look at and have to think twice about. However, when Leica announced their new Tri-Elmar-M lens to an admiring if not astonished cognoscente in 1998 it fell into neither of those categories.

Varifocal, as opposed to proper zoom lenses, have been marketed before... and in this photographic age in which the ubiquitous autofocus zoom has reached an unprecedented state of optical and mechanical quality there is little need for a lens of different focal lengths which then requires manual focusing adjustment after its focal length has been, also manually, changed. But of course the Leica M is a rangefinder camera with a direct vision viewfinder incorporating "floating" frame lines, or pairs of frames on recent models, which snap-in with individual lens changes to show the focal length in use. As such, "in-between" focal lengths cannot be seen... and anyway Leica is different as we should all know by now.

Leica must have thought hard, however, about what their customers would want and came up with a neat solution to a problem which exists, even if most photographers don't know it exists. The problem, if I can call it that, is that zooms tend to be used at either extreme of their focal lengths and not so often at the many in-between lengths that are offered. I've been as guilty of this as anyone... my regular 35-70 Nikkor was used mainly at 35mm or 70mm, and my 80-200 at either 80mm or 200mm. I suspect that many of you do the same... we simply do not use our variable focal length lenses enough at their many other variables.

Leica thus came up with an innovation that some may have thought the start of a new trend... a "varifocal" lens. Indeed some of the more hopeful were already commenting that if it could be done as a 28-35-50 then why not in the potentially more useful 35-50-70 range?

November 2006 update: I can add that with the Leica M8 digital body announced at Photokina, September 2006, the sensor crop factor of x1.33 effectively converts the 28-35-50mm Tri-Elmar to a 37-46-66mm lens... close to a very useful 35-50-70mm range. And a second Tri-Elmar-M announced at Photokina 2006 with a 16-21-24mm focal length range for the digital M8 becomes the equivalent of 21-28-32mm on a film-loading body... amazing!

Tri-Elmar-M f/4 28-35-50mm Aspheric
I should mention that this review/summary is for the first version of the Tri-Elmar... it was later superseded by a newer model with depth-of-field markings on the lens barrel and other mechanical improvements. The Tri-Elmar is a compact lens combining the three most popular focal lengths for the Leica M-series of 28mm, 35mm and 50mm. Comprising 8 elements in 6 groups the high image performance of the lens is enhanced by two "aspherical" elements being used... one to reduce distortions, the other to reduce monochromatic aberrations to a minimum.

Leica guardedly admit that overall the lens produces "good to very good" image performance at all focal lengths at between f/5.6 and f/8 with only slight distortion seen at 28mm compared to the prime 28mm f/2.8 Elmarit lens. At all three lengths the Tri-Elmar-M apparently exhibits very slight vignetting - a darkening of the corners potentially seen in even toned areas such as clear blue skies - but is totally absent two stops down at f/8. At full aperture the contrast produced by this lens is excellent and it is only necessary to stop down to f/5.6 in practice to reach optimum performance.