CANON 100MM F2 SERENAR LTM / M39
Updated June 12, 2016
|Production||January 1959 thru June 1973|
|Lens Composition||6 Elements in 4 Groups|
|Minimum Focus||1 Meter / 3.5 Feet|
|F-Stop Scale||F2 to F22; full stop detents|
|Filter Connection||58mm, Threaded|
|Lens Cap||Press On|
|Lens Hood||Canon T-60-2|
|Weight||501 grams with adapter, no lens hood|
|Lens Size||63mm Wide x 91mm Long|
Before SLRs, Canon produced rangefinder cameras and competed with Leica. Canon's rangefinder production started in 1933 and ended in 1968. Canon utilized the Canon S-Mount on their rangefinders. The S-Mount is a Leica M39 screw mount and is focus coupled - meaning the lenses will work on a Leica M rangefinder via a standard M39 to Leica M adapter. The Canon lenses are often referred to as LTM mounts; LTM means Leica Thread Mount.
The Canon 100mm F2 Serenar was introduced in 1959 and produced for 14 years. Three versions of the 100mm F2 Serenar were produced with the only differences being cosmetic - changes to the front ring and front lens cap. Canon continued to evolve the 100mm Serenar's optical design and it continued in several of Canon's early SLR lenses in the 60's and early 70's. In 1959 the 100mm F2 Serenar's MSRP price was 33,000 Yen, or ~$91 in US dollars. In today's dollars the price would be $1000-$1200 after adjusting for inflation, etc.
As one would expect from a 1960's vintage lens, the lens is metal, with more metal and some added metal for extra measure. Add a black lacquer piano finish with some matte finish silver bits, and it is classy looking as lenses go. The lens is solid with no wobble or play, manual focus is smooth (though slightly heavy) and the aperture ring click decisively from stop-to-stop in whole stop increments. Being a screw mount lens, a M39 to Leica M-mount adapter is needed; I opted for a Voigtlander 28/90.
The front lens cap is the press-on type. My first Canon 100mm Serenar had a black plastic front cap with a metal dome insert with the Canon logo in silver. My current one has a satin silver aluminum cap. A separate lens hood slips over the lens barrel and a small thumb screw holds the lens hood in place, pressing a ring against the lens barrel. Lenses with a red "EP" in a red diamond marking on the front retaining ring indicate that the lens was sold at a military exchange post, supposedly this makes the lens more collectible. There is some debate as to what the EP actually standards for, perhaps Exchange Post or Exchange Program. There is no doubt that the lenses were sold at US military PX/BX stores.
Jiro Mukai is credited for the 100mm F2 Serenar's design (along with several other Canon lenses). His work was based in part on earlier designs (and patents) from Hiroshi Ito, who refined Canon's gaussian optical design for use with faster apertures (reducing aberrations). The lens diagram is from a patent for a 6 lens, 4 group optical design is similar to the 100mm F2 Serenar:
Diagram from Canon's U.S. Patent 2681594, Issued June 1954
It is unknown (to me) if the above graphic is for the Canon 100mm F2 Serenar or one of the other 85mm Serenars. The 85mm F1.9 came first, then the 85mm F2 and 100mm F2 and the 85mm F1.8 was the last one. Hiroshi Itoh designed the earlier lenses - 85mm f/1.5, 85mm f/1.9 and 100mm f/3.5; and Jirou Mukai followed up with the 85mm f/1.8 and 100mm f/2 (source: mflenses.com). Here is a list of Canon rangefinder lenses by designer:
|Hiroshi Itoh||Jirou Mukai||Masana Kuroki||Ryouzou Furukawa|
|28mm f/3.5||25mm f/3.5||35mm f/3.5||5cm f/2 SK|
|28mm f/2.8||35mm f/1.5||50mm f/1.5||5cm f/3.5 SK|
|35mm f/3.2||35mm f/1.8||50mm f/1.9||50mm f/3.5|
|35mm f/2.8||35mm f/2||8.5cm F/2||5cm f/1.5 SK|
|50mm f/1.2||50mm f/0.95||85mm f/2||75mm f/4.5 SK|
|50mm f/1.4||50mm f/2.2||10cm f/4||13.5cm f/4 SK|
|50mm f/1.8||50mm f/2.8||100mm f/4||19mm f/3.5|
|85mm f/1.5||85mm f/1.8||1000mm f/11|
|85mm f/1.9||100mm f/2||400mm f/4.5|
|100mm f/3.5||135mm f/3.5||600mm f/5.6|
|135mm f/2.5M||800mm f/8|
Source: RangefinderForum Post
It is interesting to note that the 85mm F2 Serenar was designed by Mr. Kuroki. The 85mm F2 and 100mm F2 are often cited as being similar optical designs, so it reasonable to assume they were designed by the same person, but they were not. While trying to research the 100mm Serenar, I found several other interesting websites. AntiqueCameras.com lists the Canon LTM lenses with their market introduction date, a short comment about performance and their recent used prices (not sure how accurate the price info is). Frank Mechelhoff also provides some interesting Canon LTM history as well, click here.
The 100mm F2 Serenar is a double gauss design, commonly referred to today as a Planar™ design. The Zeiss Planar's date back to 1896 with the first symmetric lens design by Dr. Paul Rudolph. Subsequent Planars retain their doublets, though they typically are not 100% symmetric (see Wikipedia for more info). If being truly pedantic, the only official Planar lenses are Zeiss designed lenses, so the 100mm F2 Serenar LTM is best described as a Planar-like design. The 100mm Serenar was produced using Canon's new Super Spectral Coatings (S.S.C.) multi-coatings. The 100mm Serenar's front element is coated, and most likely their are some single coatings on the internal elements as well to improve light transmission. Uncoated lens elements lose ~12% of their light; whereas a coated element blocks less than 1% (assuming modern-day coatings).
The Canon 100mm F2 Serenar is a large lens by rangefinder standards. The official Canon technical specifications for the 100mm Serenar state its weight to be 515 grams. Mine weighs 501 grams including the Voigtlander adapter. For all intents and purposes, the 100mm Serenar and Leica 90mm F2 Summicron-M APO weigh the same, though the 100mm is about a 1/2 inch longer. Compared to the Leica 90mm F2 Summicron-M APO, the Canon 100mm Serenar does feel slightly nose heavy. With large lenses such as the 100mm Serenar, a Thumbs Up grip accessory helps significantly.
The Canon 100mm Serenar was produced before the days of double helicoids, so when focusing, the aperture ring rotates with the outer barrel. Another sort of "back then" feature was canting the lens ~30˚ towards the viewfinder. Supposedly this allows the photographer to see the focus distance scale via the viewfinder. All the Canon rangefinder lenses have this 30˚ cant. In use it makes no difference, but seeing an off-center lens is a bit odd (in my opinion).
Like the Nikon 105mm F2.5 P.C. (also made in a M39 LTM mount), the focus ring seemingly turns forever. Racking focus from end to end is about a 315˚ rotation of the focus ring. The 100mm Serenar is not a fast focusing lens. With Live View on the Leica M, the long focus throw is helpful with fine tuning focus. And with the very nicely dampened focus ring feel, manual focus is a joy.
Composing with a 100mm lens on a Leica M can be tricky if wanting to be exact with the 90mm framelines. I just use the 90mm framelines, shoot very loose and then crop alittle in post if needed. Exact framing requires using an EVF or Live View with the Leica M Typ 240. The Leica 1.25x Magnifier and Leica 1.4x Magnifier can help with focusing accuracy. If buying a magnifier solely for portrait lens use, I recommend the 1.4x. If buying the magnifier for general use and planning to leave it on the M most of time, the 1.25x is more practical. Of course the framelines are a total non-issue if using a Leica SL (Typ 601), Sony A7RII or similar.
A mint condition 100mm F2 Serenar can sell for $800+, plus the cost of a LTM to M-mount adapter and lens hood set-up, so the 100mm Serenar is not a low-budget lens. But, compared to the likes of the Leica 90mm F2 Summicron-M APO, the 100mm F2 Serenar is an absolute bargain. And even 50 years after its introduction, the Canon 100mm F2 Serenar is still a sought after lens for good reason:
Sharpness - The Canon 100mm Serenar is surprisingly sharp both wide-open and stopped down. Today's press releases talk of aspherical elements, specialized low dispersion glass, refractive this, diffractive that... These announcements sound like revolutionary advancements, and imply anything prior is garbage. Honestly, I have been amazed at how sharp and detailed these mid-century lenses can be. Even at F2 the 100mm Serenar can compete head-to-head with a modern lens.
Contrast - Lenses from this era are often characterized as having less contrast. "Less contrast" does NOT mean "no contrast". Obviously there is contrast, but it is a different character. The blacks are not as deep, but the mid-tones have more tonality and nuance. There can be some nice micro-contrast in the bokeh. The 100mm F2 Serenar has an amazingly ability to compress dynamic range. It is common for the histogram in Capture One to look like:
Histogram from Phase One's Capture One
Note the additional headroom in the highlight range and that the histogram trails off towards the deep blacks. On one hand the lens is very capable of containing / retaining highlights. On the other hand, the images can look flat (lots of mid-tones with no highlights or dark shadows) and need post processing to have that contrast "pop". Stretching the histogram adds "pop" and lessen the mid-tone look, though, sometimes the mid-tone look really works - especially for black and white images.
Bokeh - The picture below compares the wide open bokeh from the Canon 100mm Serenar to the Leica 90mm F2 Summicron-M APO. At first the pictures seem similar, but if looking closer, the Canon 100mm LTM is more abstracted, especially in the image on the right.
Canon 100mm Serenar Bokeh vs Leica 90mm Summicron-M APO
The lower contrast and added 10mm in reach result in a slightly gentler bokeh. The 100mm Serenar's bokeh has a degree of modern Canon DNA in it. The bokeh has more gaussian blur and is more diffused than a Leica M ASPH lens. The added 10mm of reach (compared to a 90mm lens) goes a long way towards smoothing the bokeh as well. If anything gives the 100mm Serenar a "fingerprint", it is the lens' blend of bokeh and contrast. The images are more subdued than those from Leica 90mm F2 Summicron-M APO. To my eye the Canon 100mm Serenar's pictures have more relaxed look.
Aberrations, Flare and Distortion - At F2 there can be some purple color fringing in high contrast areas:
Chromatic Aberrations - Click Image to Enlarge
Sensor bloom could be compounding the issue. The purple CA is easily removed today in Capture One or Lightroom. And like most lenses, the CA goes away when the lens is stopped down by a stop or two. For a 1950's lens, the performance is very impressive. As for flare, the 100mm F2 Serenar will flare if shot into the sun. The effect ranges from crappy to awesomeness. Currently I am using a Heliopan 72mm Metal Lens Hood (Long) with a step-up ring, hoping to reduce the stray light - night shots can be tricky if there is a street lamp to the right or left. Also, I have also seen the light bounce off the sensor and reflect back off the aperture blades (aperture was at F22) and ghosts of the aperture blades became part of the image:
Aperture Blade Reflections - Click Image to Enlarge
This anomaly is most likely due to no (or inferior) lens coatings on internal element(s) - lens multi-coatings were in their infancy in the 1950-1960's. With 1000's of pictures taken, I have seen this happen in this one shot. Generally 100mm lenses typically have little distortion. Having shot many cityscapes in Dallas and Seattle, I would say the 100mm Serenar is effectively distortion free. Nor, have I noticed any focus shift or curvature of field.
3D Effect - Netting a 3D effect depends heavily on lighting, and given the right conditions the Canon 100mm F2 Serenar has a 3D look or feel occassionally. The overall fingerprint or draw is similar to Canon’s current SLR lens offerings, such as the Canon EF 100mm f/2 USM Lens and Canon EF 85mm f/1.8 USM Lens.
Flare - If shot into or towards the general of the sun (or any other bright light source), the 100mm Serenar is likely to flare. If not wanting flare, I would probably choose the Leica 90mm APO for these types of harsher shooting conditions.
After using the Nikon 105mm F2.5 P.C. and Canon 100mm F2 Serenar, I am truly amazed at how sharp these classic lenses are. I enjoy the Leica M’s simplicity and mechanical nature. Adding the Canon 100mm F2 Serenar enhances the retro experience. The Canon 100mm Serenar's performance only makes the experience better. The Canon 100mm F2 Serenar LTM also has the smoothest, cleanest bokeh of my M lenses. And while that is nice, it is the overall "feel" of the images I like - the black and white images look very film-like. Color images tend to be slightly subdued (due to the lower contrast), sometimes the look works, other times times a healthy does of editing is needed.
Shooting 100mm lens on a rangefinder takes practice. Fortunately my Canon 100mm F2 Serenar is well calibrated and the keeper rate has been around 50% at F2, though, I tend to shoot F2.8 for some added wiggle room. The Leica M Type 240 with the EVF (or live view) changes the dynamic considerably and makes wide open shooting easier. Next, the 100mm F2 Serenar’s long focus throw takes patience as well. The 100mm Serenar is not a quick focusing lens. Lastly, using 90mm frame lines for a 100mm focal length can be hit-or-miss at times. I shoot loose, leaving room for cropping and finalizing the composition during post processing.
With those caveats noted, the Canon 100mm F2 Serenar earns a big thumps up. If wanting a more contrasty image and minimal CA, the Leica 90mm F2 Summicron-M APO is the way to go. On the Leica M-P Typ 240 I do prefer the 90mm APO because it is more compact, has the built-in hood and is an optical powerhouse.