Leica-M 135mm lenses: a review
When Leica launched the APO-Telyt-M 1:3.4/135mm in 1998, it replaced two 135mm lenses that had until then been part of the M-system lineup: the Elmarit-M 1:2.8/135mm and the Tele-Elmar-M 1:4.0/135mm. Both were well regarded in the Leica community for their optical quality, but the APO-Telyt promised to add further tack to sharpness and contrast thanks to its apochromatic correction.
In terms of maximum aperture, the APO-Telyt was placed in the middle of its two predecessors: it is half an f-stop slower than the Elmarit-M and half an f-stop faster than the Tele-Elmar-M. Similar to the lenses it replaced, the APO-Telyt-M features a built-in, sliding lens hood. It is lighter and more compact than its predecessors, with the difference being particularly marked in comparison with the Elmarit-M (that comes with magnifying viewfinder "goggles").
In addition to the three most recent lenses, there are older 135mm designs that can be mounted on M-system cameras. These include notably the Hektor 1:4.5/13.5cm, which was produced from 1933 to 1960, the Elmar 1:4/135mm that was in production from 1960 to 1965, and the Tele-Elmar of 1965 to 1990. While the Hektor is generally seen as being below average in terms of optical performance, the Elmar and Tele-Elmar are sometimes regarded, including by expert-bloggers Ken Rockwell and Ashwin Rao, as second-hand bargain alternatives to the more recent lens designs.
|Headline specifications of 135mm lenses for the Leica M-system|
(m / #)
|Leica Hektor 13.5cm f/4.5||4.5 - 32||4 / 3||1.5 / 9||A36/E39||127.5 / 51.0||440-555||1933-60||150-300||check|
|Leica Elmar 135mm f/4||4.0 - 22||4 / 4||1.5 / 9||E39||122.7 / 53.0||440||1960-65||250-350||check|
|Leica Tele-Elmar 135mm f/4||4.0 - 22||5 / 3||1.5 / 9||E39/E46||112.0 / 59.0||510||1965-90||500-1,300||check|
|Leica Elmarit-M 135mm f/2.8||2.8 - 32||5 / 4||1.5 / 9||E55||114.0 / 66.0||735||1976-96||350-700||check|
|Leica Tele-Elmar-M 135mm f/4||4.0 - 22||5 / 3||1.5 / 9||E46||112.0 / 59.0||550||1990-98||1,200-2,000||check|
|Leica APO-Telyt-M 135mm f/3.4||3.4 - 22||5 / 4||1.5 / 9||E49||104.7 / 58.5||453||1998-today||2,400-3,000||check|
Contrast and sharpness compared
Leica publishes optical performance information for its lenses in technical specification brochures and in special booklets, such as the one edited by Erwin Puts on "Leica M-Lenses: Their Soul and Secrets". The underlying data are gathered under consistent conditions and can, hence, be used to compare the optical performance of different lenses. In particular, Leica makes MTF information for different spatial line pair frequencies available: The 5 lp/mm and 10 lp/mm data can be taken as indicators of contrast reproduction, while the 20 lp/mm and 40 lp/mm MTF data reflect the ability of lenses to reproduce fine image detail, and thus determine lens performance. This information is provided both in tangential and sagittal direction within the image.
In order to keep the presentation concise, the subsequent comparison of the three 135mm lenses for the Leica M-system is based on the MTF data for 10 lp/mm (for contrast) and 40 lp/mm (for sharpness) only. Moreover, tangential and sagittal MTF data points have been averaged. These data suggest that the APO-Telyt-M provides better contrast than the Elmarit-M and the Tele-Elmar-M, both at maximum aperture and when stopped down to f5.6.
The difference between the lenses is not very big, though. The APO-Telyt-M and the Tele-Elmar-M are roughly at the same, very high level, while the Elmarit-M trails somewhat when evaluated wide-open. However, this lens is faster than the other two and it improves when stopped down.
The advantage of the newer, more elaborately corrected APO-Telyt-M becomes more obvious when looking at the reproduction of very fine detail (second diagram). Even wide open, its MTF for 40 line pairs per mm stays above 50% across (virtually) the entire image area. The Tele-Elmar-M and the Elmarit-M are clearly less sharp when used at their maximum aperture. Stopping down to f5.6 results in increased, and now excellent sharpness of all three lenses, but the APO-Telyt-M retains an edge over its predecessors.
Vignetting is low for all three lenses with the light fall-off wide-open amounting to less than half an f-stop. Similarly, the slight pincushion distortion of the three lenses of less than 1% will not be an issue in practical use.
The comparison review reveals that the APO-Telyt-M represents an improvement over its predecessors, the Elmarit-M and the Tele-Elmar-M. It is the most compact of the three lenses and provides superior contrast and sharpness, with its strong performance at maximum aperture being particularly noteworthy. The Tele-Elmar-M also delivers very high contrast and sharpness values, which is in line with its reputation of also being an apochromatically corrected lens without Leica advertising this characteristic when it was released.
The diagrams suggest that the Elmarit-M is the weakest of the trio, especially when evaluated at maximum aperture. However, it is a full f-stop faster than the Tele-Elmar-M and as its contrast and sharpness performance improves markedly when stopped down, it might close in on the MTF resolution of the Tele-Elmar-M when assessed at an identical aperture, such as f=4. Unfortunately, Leica does not make the MTF data available to check this hypothesis. In any case, the Elmarit-M offers the opportunity to open the aperture one stop further than the Tele-Elmar-M when shooting conditions require to do so, while the latter represents a significantly smaller lens that weighs 25 percent less.
The optical quality and feature differences are reflected in lens prices. The APO-Telyt-M is the most costly one to acquire, retailing new at about USD 3,500 and trading on the second-hand market for USD 2,400-3,000. The Tele-Elmar-M still commands relatively high prices on ebay, with the price for a copy in excellent condition ranging from USD 1,200 to 2,000. In comparison, the Elmarit-M is a bargain that can be found for USD 350-700. This relatively low price seems to reflect the lack of popularity of the lens due to its bulky nature that sits somewhat at odds with the small-package philosophy of the M-system. Anyway, you can't go terribly wrong with any of the three lenses. Happy shooting!
A 28mm wide-angle lens makes a nice complement to the 135mm tele, so that you might want to check out the available 28mm options for Leica-M. An overview of all M-mount lenses, including optics by Voigtländer and Zeiss, can be found in the Leica M lens compendium. Moreover, there is a comparison of the different Leica M-cameras on this site that might be of interest.