Topcon Lenses: Still tops after all these years
Tokyo Optical Co. (Topcon) made lenses that are sharp and much more
By Jason Schneider
Topcor SLR lenses in RE bayonet mount and the earlier Simlar and Topcor lenses in Leica screw mount, all made by the Tokyo Optical Co., have attained a cult following among connoisseurs of vintage lenses. Some hyperbolic Topcor/Simlar lens fans have even proclaimed that they blow the corresponding Nikon, Canon, Zeiss, and Leitz lenses out of the water. The truth is somewhat less earthshaking, but still impressive. In fact, the lenses made by Tokyo Optical Co. during the vintage era (roughly the early ‘50s through the mid ‘80s) do deliver exceptional imaging performance with remarkable consistency and they’re justly renowned for their signature combination of, superb sharpness, crisp detail, and distinctive natural rendition.

An optical legend: 58mm f/1.4 RE.Auto-Topcor is renowned for its superb definition and gorgeous rendition and is prized by portraitists and art photographers.
Some examples, notably the superlative 58mm f/1.4 R.E. Auto-Topcor in Exakta-compatible Topcon RE bayonet mount, are considered timeless classics and have even been lovingly replicated, complete with Tokyo Optical Co markings no less, by Cosina! Others, including the earlier screw mount Simlars and Topcors of the ‘50s do occasionally outperform their counterparts from Nikon Zeiss, Canon, and Leitz, but many “merely” equal their more illustrious competitors—no mean accomplishment. After WW II Tokyo Optical Co. began producing 39mm screw mount lenses for the Leotax, a well-made Leica copy, and then marketed them (alas, not very aggressively) to Leica users. These are now prized user-collectibles, some of which fetch fancy prices.

Tokyo Optical Co.'s first camera was the Lord, a 6x4.5 cm coupled rangefinder camera with a 7.5cm f/3.5 Toko-Anastigmat lens. Ingenious, but it didn't;t sell.
Tokyo Optical Company, Ltd. was founded in 1932, and like Nippon Kogaku (later Nikon) it began as an optical manufacturing company. Tokyo Optical Co. famously supplied lenses and optical instruments to the Imperial Japanese Army while Nippon Kogaku made lenses, binoculars, and optical instruments for the Imperial Japanese Navy. During the ‘30s Tokyo Kogaku designed super speed objectives for fluoroscopy with apertures as wide as f/0.7 and, in 1938 came up with the remarkable (uncoated) 50mm f/1.5 Simlar lens, one of the finest f/1.5 lenses of the prewar era. Available in Leica screw mount, this unconventional 7-element, 4-group Double Gauss design by Tomita Ryoji, was patented but nevertheless copied by J.H. Dallmeyer the venerable English optical firm, early in WWII and offered as the 2-inch f/1.5 Dallmeyer Anastigmat Septac -- one of very few instances of a famed European optical company appropriating a Japanese lens design! Tokyo Optical only made about 4,000 of the original series, and later made coated versions of the 50mm f/1.5 Simlar based on a different optical formula. Either one is a great lens, quite sharp in the center, with gobs if character and distinctive bokeh, but they’re expensive—the later coated version currently fetches about $2-3k in clean working condition, and earlier uncoated examples are astronomically priced.

Postwar coated 50mm f/1.5 Similar used a different optical formula from landmark uncoated version (not shown) copied by Dallmeyer, Both are rare & pricey.

2-inch f/1.5 Dallmeyer Anastigmat Septac of c.1941 was based on the ingenious 7-element 4-group 50mm f/1.5 Simlar of 1938. Both were great in their day.
Tokyo Optical Company also made excellent non-interchangeable leaf shutter lenses for a variety of medium format cameras, including the Primoflex and Laurelflex TLRs, the Mamiya Six IV, and of course its own very first camera, the Lord, an ingenious but not very successful 4.5×6 folder with a coupled rangefinder released in 1937. All these Tokyo Optical Co. lenses, perform very well, often better than their contemporaries. After terminating 35mm SLR camera production at the end of 1980 Topcon provided superb Topcor lenses for the pro-caliber Horseman 6 x 9cm Horseman VH and VH-R press/view cameras and helped to develop and provide lenses for the Horseman ER-1.

Topcon RE Super of 1963, sold in the USA as the Beseler Topcon Super D, was a technological tour de force that made Tokyo Optical Co. a top contender.
Topcon began producing 35mm SLRs in 1957 before either Nikon or Canon, but their pièce de resistance was the Topcon RE Super of 1963 -1971 that was sold in the U.S. as the Beseler Topcon Super D. Rugged and versatile, it was the first SLR with an in-body TTL metering employing CdS cells ingeniously positioned behind slits in the instant-return mirror. It was aimed primarily at pros with its removable pentaprism, interchangeable screens, an array of high-performance Topcor lenses from 20-500mm, and a full line of system accessories. The Topcon Super D sold quite well but it wasn’t promoted as aggressively as the hugely popular Nikon F and it never enjoyed the same panache among pros. But every dog has its day, and that day came for Tokyo Kogaku when they won a contest to see who could manufacture the official combat camera of the United States military. The Topcon Super D beat out its archrivals from Nikon and Canon and was quickly adopted by the U.S. Navy as their official combat camera until production finally ceased in 1971. Throughout its lifetime, the Topcon RE- and D-series SLRs built a legendary reputation among hardcore shooters as a beautiful, bulletproof cameras with lenses that could go toe-to-toe with the best that Zeiss, Leitz, Nikon, and Canon had to offer.
Tokyo Optical Co lenses in Leica Screw Mount: A quick overview
All are beautifully made, have precision brass helicals for smooth focusing action, and most examples are finished in chrome.

50mm f/3.5 collapsible Similar was a Leitz Elmar clone at least as good and maybe a tad better than the original. It was made for the Leotax, a Leica copy.

Leotax, a well-made Japanese Leica copy of the '50s and '60s is shown here with a collapsible 50mm f/3.5 C. (for coated) Similar lens, a common pairing.
The 50mm f/3.5 collapsible C, Simlar, Simlar, and Topcor are all excellent quality, coated 4-element 3-group Tessar formula lenses that perform as well as or slightly better than a good Zeiss Tessar or Leitz Elmar. My own collapsible 50mm f/3.5 Topcor edges out my prized 50mm f/3.5 Red Scale Leitz Elmar in terms of sharpness at the widest apertures, and equals its “smooth, rounded” rendition and beautiful bokeh. According to user reviews, the rigid mount 50mm f/3.5 Topcor K with aluminum barrel performs similarly, and the rare, rigid 50mm f/2.8 Topcor, a 5-element, 3-group Heliar design that’s available in black or chrome, is even sharper, especially off axis at its widest apertures. It blows the 50mm f/2.8 Canon LTM (a good Tessar type) right out of the water and edges out the vaunted 50mm f/2.8 collapsible Leitz Elmar.

Rigid 50mm f/2 Topcon S in Leica screw mount was an excellent choice for Leica shooters in the '50s; not quite a Summicron but a fine lens at a bargain price.
The 50mm f/2 Topcor, Topcor S, and black finish 50mm f/1.8 Topcor S are all outstanding normal lenses, the former of classic 6-element 4-group construction, and both "S" versions using a 7-element design that performs a bit better off axis at the widest apertures. Both are on a par with the best of their competitors from Nikon, Canon, and Zeiss, being edged out only by the 50mm f/2 Leitz Summicron. Both the 50mm f/1.5 Simlar and Topcor are commendably sharp even wide open, and have beautiful bokeh at their widest apertures, but for wildly distinctive “expressive” bokeh, the (wildly expensive) 50mm f/1.5 Simlar is most assuredly the hot ticket.
Other Tokyo Optical Co. LTM mount lenses include the 35mm f/2.8 Topcor (sold with huge external finder) the 90mm f.4 C Simlar, 90mm f/3.5 Topcor with aluminum barrel and knurled rings (sold with external finder) and the 135mm f/3.5 Topcor, which originally came with an accessory multi-frame 50/90/135nn finder. Regrettably, I haven’t had hands-on shooting experience with any of the lenses in this group but based in hands-on universally enthusiastic user reviews all provide Tokyo Optical Co.’s signature combination of outstanding sharpness, and smooth natural rendition.
Tokyo Optical Co. R.E. Auto-Topcor lenses in Topcon RE bayonet mount
Topcor RE lenses made by Tokyo Optical Co. range from a 20mm f/4 to a 500mm f/5.6 and include an 87-205mm f/4.7 zoom and 3 macro lenses without focusing mounts designed for bellows use. The full range of 18 lenses is respectable, but totally outclassed by the enormous line of F-mount Nikkors for Nikon SLRs and the number of Canon FT and FD lenses in the Canon system. The fact that the Topcon used what is essentially an Exakta bayonet mount rotated 180 degrees for convenient right-handed operation, imposed limitations on possible lens designs. The inner diameter of the mount is a mere32.5 mm, and the outer diameter (prongs included) is 37.5 mm). In other words, the mount is narrower that the M39 Leica screw mount, making it impossible to design anything wider and faster than a 20mm f/4, and extremely difficult to design any RE mount lens faster than f/1.4. Despite these restrictions, Topcor RE lenses are generally prized for their performance and many are considered priceless gems. Here are some hands-on evaluations based on my experiences shooting them on my Topcon R.E. Super, Beseler Topcon Super D, and Topcon Super DM.

Topcon's 87-205 f/4.7 Auto-Topcor Zoom is not a thing of beauty, but it performs surprisingly well for a zoom of its era, and you can snag one for under $100..
Topcor 58mm f/1.4 RE Auto: The most acclaimed normal lens for Topcon SLRs is visually impressive with its massive front element, single coated on most versions, and its smooth turning, striated, rubberized focusing ring that takes the lens down to an impressive 45cm ( a little under 18 inches). Because of its longish normal focal length of 58mm (which gives 1:1 viewing) this is close enough for frame-filling head shots of kids, one of my favorite subjects. Based on a 7-element 5-group modified Planar design it delivers exquisite central sharpness at all apertures, superb definition across the field by f/4, and gorgeous bokeh at its widest apertures despite having a 6-bladed diaphragm that typically produced the dreaded “honeycomb effect” in out-of-focus highlights. Overall contrast is modest by modern standards, which helps to enhance its smooth tonal gradation, but it’s still high enough to make the images “pop.” The shorter focal length final iteration of this classic design is the RE GN Topcor M 50mm f/1.4 of 1973. Based on the same 7-element, 5-group optical formula as the 58mm, it’s multicoated, focuses down to 0.4m (15.7 inches) and provides flash guide number (GN) footage settings from 32-250. It’s a very nice lens, it’s radioactive (check out the B&H video online) but it’s bokeh is “busier” than the 58mm version. Yes, it’s a good, sharp lens but in my opinion, it lacks the character of the Topcor 58mm f/1.4 RE Auto, and it’s expensive—about $400-$800 0n the leading online auction sites. If you’re so inclined, you’re probably better off snagging a pristine Topcor 58mm f/1.4 RE Auto for $300-$500. It’s available in chrome or black finish (the latter at higher cost) and there are minor cosmetic variations mostly of interest to Topcon collectors more manic than I.

The "sleeper" of the Topcon RE Auto-Topcor line, the 58mm f/1.8 doesn't have the pizzazz of the big 58mm f/1.4, but it's a superb lens and more compact.
Topcor 58mm f/1.8 RE Auto: This 6-element, 5-group classic was the less expensive, slightly smaller alternative to the Topcor 58mm f/1.4 RE Auto and it also debuted in 1963 along with the Topcon R.E. Super. It’s the sleeper of the line, and were it not for its more glamorous 2/3 of a stop faster stablemate that provides a slightly brighter focusing image and razor thin depth of field wide open. the 58mm f/1.8 would be it would be the flagship normal lens in in the Topcor RE line. It’s a magnificent lens, exquisitely sharp wide open in the center, tack sharp across the field by f/4, and capturing smooth natural rendition, good contrast, and excellent tonal gradation at all settings. Like the 58mm f/1.4, it focuses down to 0.45cm (just under 18 inches) for frame-filling head shots, delivers gorgeous bokeh at its widest apertures, and focuses with commendable smoothness. You can snag one of these beauties in pristine shape for about $150-$200 in chrome or $300-$400 in black on the leading online auction sites.

The 100mm f/2.8 RE. Auto-Topcor is an outstanding portrait tele for film or digital imaging. This is the rare U.S. Navy version denoted with a red "N."
Topcor 10cm (100mm) f/2.8 RE Auto: A lens prized by collectors and users, especially those who adapt it to digital, this outstanding portrait lens introduced in 1965 is remarkably compact, is single layer coated, and features Heliar-type construction consisting of 5 elements in 3 groups. It’s extremely sharp even at f/2.8, with the corners coming in at about f/4 and it’s acclaimed for its smooth attractive bokeh in out of focus image areas despite having a 6-bladed diaphragm. Its contrast is moderate compared to current lenses, but its images can still “pop” while also retaining that rounded “vintage” rendition with long tonal gradation that many contemporary portrait photographers favor. The lens focuses down to 4 feet, close enough for head shots, but it does tend to flare in backlit situations, so a lens hood is recommended. The little Topcor 100 is beautifully balanced on any camera from a big Topcon Super D to a compact full-frame mirrorless, which makes it a great choice for handheld shooting. A pristine 100mm RE Topcor currently fetches about $250-300 in chrome, and the U.S Navy version marked with a red “N” commands prices in the $500-$600 range. It’s my second favorite Topcor after the 58mm f/1.4.

The 85mm f/1,8 RE. Auto-Topcor is a spectacular performer, but only about 1000 were made and it's now a rare and pricey collectible.
Topcor 85mm f/1.8 RE Auto: Introduced as a wide aperture medium tele for portraiture in 1973, this high-performance 6-element, 5-group lens focuses down to 0.9m (3 feet), close enough for frame-filling head shots, has a 6-bladed diaphragm, and weighs in at a moderate 16.9ounces. According to press and user reviews, it’s extremely sharp, the best in its class, and provides beautiful vintage rendition and smooth attractive bokeh at its widest apertures despite its (you guessed it) 6-bladed diaphragm. Thanks to its wide f/1.8 maximum aperture it’s awesome for creating artistic effects using limited depth of field. Regrettably I’ve never shot with one of these jewels, and I’d love to acquire one. However according to creditable sources only about 1,000 were made and collectors have snapped up most of them, resulting in online auction prices in the $2,000-$3,000 range, a bit too rich for my blood. I guess I’ll just have to content myself with my superb 1+ stop slower much smaller and lighter 100mm f/2.8 RE Topcor-

Topcon 20mm f/4 RE Auto is the widest lens possible given the narrow diameter of the Exakta mount Topcon used, but it's a magnificent ultra-wide equal to the best.
Topcor 20mm f/4 Auto: This 8-element, 6-group ultra-wide-angle masterpiece is a “radical retrofocus design” that was introduced in 1968 at the then very high price of $279.95. It covers a field of 94.5 degrees, focuses down to 1 foot, and stops down to f/22. Acclaimed for its extremely low linear distortion and crisp imaging, reviewers laud it as a “great lens,” but regrettably only about 1,500 were made so it’s relatively rare and quite expensive. Produced only in chrome finish and employing a dedicated clamp-on lens hood, it fetches about $700-$1,000 on the top online auction sites—if you take the plunge try to get it get it with the lens hood!

A 35mm f/2.8 doesn't sound exciting, but this RE. Auto-Topco is extremely sharp and well corrected, and delivers outstanding performance at a modest price.
Topcor 3.5cm (35mm) f/2.8 RE Auto: This outstanding moderately wide-angle f/2.8 employs an impressive 7-element, 5-grpup optical formula that delivers razor sharp images with low distortion and just a hint of vintage character thanks to its warm color rendition and moderate contrast. The corners come in at f/4, and it has smooth attractive bokeh (noticeable mostly in close-ups shot at its widest apertures) despite its 6-bladed diaphragm. It also focuses down to a commendably close 9 inches, which is great for nature studies and the like. It’s readily available in chrome or black at the relatively modest cost of $150-$300. Based on my hands-on experience it’s a winner.

58mm f/3.5 RE. Macro Auto Topcon is a true macro lens that gets down to 1:2 on its own but also delivers superb performance at normal focusing distances.
Topcor 58mm f/3.5 RE Macro Auto: Based on a 5-element, 4-group Xenotar-type design, this true macro lens gets down to 1:2 (10 inches) and it’s exceptionally sharp, has close to zero linear distortion, and virtually no off-axis light falloff even wide open. Indeed, its performance at infinity rivals that of most standard lenses, which greatly enhances its shooting flexibility. Since its front element is deeply recessed, a lens hood is not needed, and it can get down to 1:1 (life-size on film or sensor) with a dedicated or third-party extension tube. This gem is currently available all the usual places at $200-$350 in chrome finish and, and $500-$550 in black.
Obviously, there are many more Topcor lenses in RE mount that we couldn’t fully cover or review here, but you won’t go wrong with any of them in terms of their overall performance on film or adapted for digital capture. It is evident that the company acquired an incredibly sophisticated level of optical expertise by the mid to late ‘30s, and their intensive wartime experience in making optics for the Japanese Army served to hone the company’s impressive skill set. The ability to innovate quickly was another key part of Tokyo Optical Co.’s corporate culture. Indeed, by the late ‘50s they offered the gargantuan 300mm f/2.8 and hefty 135mm f/2 Topcor-R (pre-set diaphragm) lenses, which held the record for speed in their respective classes for many years.
If the amazing story of Tokyo Optical Co. reveals anything it’s the crucial importance of marketing in creating a brand image. While Topcor lenses were always as good as and often better than their competitors their marketing was not. Fortunately, we can still enjoy shooting with these optical classics now, and I can attest on the basis on my personal experience, that they’re bloody fantastic, have gobs of character and can capture truly beautiful images that stand the test of time.
Tokyo Optical Co. (Topcon) made lenses that are sharp and much more
By Jason Schneider
Topcor SLR lenses in RE bayonet mount and the earlier Simlar and Topcor lenses in Leica screw mount, all made by the Tokyo Optical Co., have attained a cult following among connoisseurs of vintage lenses. Some hyperbolic Topcor/Simlar lens fans have even proclaimed that they blow the corresponding Nikon, Canon, Zeiss, and Leitz lenses out of the water. The truth is somewhat less earthshaking, but still impressive. In fact, the lenses made by Tokyo Optical Co. during the vintage era (roughly the early ‘50s through the mid ‘80s) do deliver exceptional imaging performance with remarkable consistency and they’re justly renowned for their signature combination of, superb sharpness, crisp detail, and distinctive natural rendition.

An optical legend: 58mm f/1.4 RE.Auto-Topcor is renowned for its superb definition and gorgeous rendition and is prized by portraitists and art photographers.
Some examples, notably the superlative 58mm f/1.4 R.E. Auto-Topcor in Exakta-compatible Topcon RE bayonet mount, are considered timeless classics and have even been lovingly replicated, complete with Tokyo Optical Co markings no less, by Cosina! Others, including the earlier screw mount Simlars and Topcors of the ‘50s do occasionally outperform their counterparts from Nikon Zeiss, Canon, and Leitz, but many “merely” equal their more illustrious competitors—no mean accomplishment. After WW II Tokyo Optical Co. began producing 39mm screw mount lenses for the Leotax, a well-made Leica copy, and then marketed them (alas, not very aggressively) to Leica users. These are now prized user-collectibles, some of which fetch fancy prices.

Tokyo Optical Co.'s first camera was the Lord, a 6x4.5 cm coupled rangefinder camera with a 7.5cm f/3.5 Toko-Anastigmat lens. Ingenious, but it didn't;t sell.
Tokyo Optical Company, Ltd. was founded in 1932, and like Nippon Kogaku (later Nikon) it began as an optical manufacturing company. Tokyo Optical Co. famously supplied lenses and optical instruments to the Imperial Japanese Army while Nippon Kogaku made lenses, binoculars, and optical instruments for the Imperial Japanese Navy. During the ‘30s Tokyo Kogaku designed super speed objectives for fluoroscopy with apertures as wide as f/0.7 and, in 1938 came up with the remarkable (uncoated) 50mm f/1.5 Simlar lens, one of the finest f/1.5 lenses of the prewar era. Available in Leica screw mount, this unconventional 7-element, 4-group Double Gauss design by Tomita Ryoji, was patented but nevertheless copied by J.H. Dallmeyer the venerable English optical firm, early in WWII and offered as the 2-inch f/1.5 Dallmeyer Anastigmat Septac -- one of very few instances of a famed European optical company appropriating a Japanese lens design! Tokyo Optical only made about 4,000 of the original series, and later made coated versions of the 50mm f/1.5 Simlar based on a different optical formula. Either one is a great lens, quite sharp in the center, with gobs if character and distinctive bokeh, but they’re expensive—the later coated version currently fetches about $2-3k in clean working condition, and earlier uncoated examples are astronomically priced.

Postwar coated 50mm f/1.5 Similar used a different optical formula from landmark uncoated version (not shown) copied by Dallmeyer, Both are rare & pricey.

2-inch f/1.5 Dallmeyer Anastigmat Septac of c.1941 was based on the ingenious 7-element 4-group 50mm f/1.5 Simlar of 1938. Both were great in their day.
Tokyo Optical Company also made excellent non-interchangeable leaf shutter lenses for a variety of medium format cameras, including the Primoflex and Laurelflex TLRs, the Mamiya Six IV, and of course its own very first camera, the Lord, an ingenious but not very successful 4.5×6 folder with a coupled rangefinder released in 1937. All these Tokyo Optical Co. lenses, perform very well, often better than their contemporaries. After terminating 35mm SLR camera production at the end of 1980 Topcon provided superb Topcor lenses for the pro-caliber Horseman 6 x 9cm Horseman VH and VH-R press/view cameras and helped to develop and provide lenses for the Horseman ER-1.

Topcon RE Super of 1963, sold in the USA as the Beseler Topcon Super D, was a technological tour de force that made Tokyo Optical Co. a top contender.
Topcon began producing 35mm SLRs in 1957 before either Nikon or Canon, but their pièce de resistance was the Topcon RE Super of 1963 -1971 that was sold in the U.S. as the Beseler Topcon Super D. Rugged and versatile, it was the first SLR with an in-body TTL metering employing CdS cells ingeniously positioned behind slits in the instant-return mirror. It was aimed primarily at pros with its removable pentaprism, interchangeable screens, an array of high-performance Topcor lenses from 20-500mm, and a full line of system accessories. The Topcon Super D sold quite well but it wasn’t promoted as aggressively as the hugely popular Nikon F and it never enjoyed the same panache among pros. But every dog has its day, and that day came for Tokyo Kogaku when they won a contest to see who could manufacture the official combat camera of the United States military. The Topcon Super D beat out its archrivals from Nikon and Canon and was quickly adopted by the U.S. Navy as their official combat camera until production finally ceased in 1971. Throughout its lifetime, the Topcon RE- and D-series SLRs built a legendary reputation among hardcore shooters as a beautiful, bulletproof cameras with lenses that could go toe-to-toe with the best that Zeiss, Leitz, Nikon, and Canon had to offer.
Tokyo Optical Co lenses in Leica Screw Mount: A quick overview
All are beautifully made, have precision brass helicals for smooth focusing action, and most examples are finished in chrome.

50mm f/3.5 collapsible Similar was a Leitz Elmar clone at least as good and maybe a tad better than the original. It was made for the Leotax, a Leica copy.

Leotax, a well-made Japanese Leica copy of the '50s and '60s is shown here with a collapsible 50mm f/3.5 C. (for coated) Similar lens, a common pairing.
The 50mm f/3.5 collapsible C, Simlar, Simlar, and Topcor are all excellent quality, coated 4-element 3-group Tessar formula lenses that perform as well as or slightly better than a good Zeiss Tessar or Leitz Elmar. My own collapsible 50mm f/3.5 Topcor edges out my prized 50mm f/3.5 Red Scale Leitz Elmar in terms of sharpness at the widest apertures, and equals its “smooth, rounded” rendition and beautiful bokeh. According to user reviews, the rigid mount 50mm f/3.5 Topcor K with aluminum barrel performs similarly, and the rare, rigid 50mm f/2.8 Topcor, a 5-element, 3-group Heliar design that’s available in black or chrome, is even sharper, especially off axis at its widest apertures. It blows the 50mm f/2.8 Canon LTM (a good Tessar type) right out of the water and edges out the vaunted 50mm f/2.8 collapsible Leitz Elmar.

Rigid 50mm f/2 Topcon S in Leica screw mount was an excellent choice for Leica shooters in the '50s; not quite a Summicron but a fine lens at a bargain price.
The 50mm f/2 Topcor, Topcor S, and black finish 50mm f/1.8 Topcor S are all outstanding normal lenses, the former of classic 6-element 4-group construction, and both "S" versions using a 7-element design that performs a bit better off axis at the widest apertures. Both are on a par with the best of their competitors from Nikon, Canon, and Zeiss, being edged out only by the 50mm f/2 Leitz Summicron. Both the 50mm f/1.5 Simlar and Topcor are commendably sharp even wide open, and have beautiful bokeh at their widest apertures, but for wildly distinctive “expressive” bokeh, the (wildly expensive) 50mm f/1.5 Simlar is most assuredly the hot ticket.
Other Tokyo Optical Co. LTM mount lenses include the 35mm f/2.8 Topcor (sold with huge external finder) the 90mm f.4 C Simlar, 90mm f/3.5 Topcor with aluminum barrel and knurled rings (sold with external finder) and the 135mm f/3.5 Topcor, which originally came with an accessory multi-frame 50/90/135nn finder. Regrettably, I haven’t had hands-on shooting experience with any of the lenses in this group but based in hands-on universally enthusiastic user reviews all provide Tokyo Optical Co.’s signature combination of outstanding sharpness, and smooth natural rendition.
Tokyo Optical Co. R.E. Auto-Topcor lenses in Topcon RE bayonet mount
Topcor RE lenses made by Tokyo Optical Co. range from a 20mm f/4 to a 500mm f/5.6 and include an 87-205mm f/4.7 zoom and 3 macro lenses without focusing mounts designed for bellows use. The full range of 18 lenses is respectable, but totally outclassed by the enormous line of F-mount Nikkors for Nikon SLRs and the number of Canon FT and FD lenses in the Canon system. The fact that the Topcon used what is essentially an Exakta bayonet mount rotated 180 degrees for convenient right-handed operation, imposed limitations on possible lens designs. The inner diameter of the mount is a mere32.5 mm, and the outer diameter (prongs included) is 37.5 mm). In other words, the mount is narrower that the M39 Leica screw mount, making it impossible to design anything wider and faster than a 20mm f/4, and extremely difficult to design any RE mount lens faster than f/1.4. Despite these restrictions, Topcor RE lenses are generally prized for their performance and many are considered priceless gems. Here are some hands-on evaluations based on my experiences shooting them on my Topcon R.E. Super, Beseler Topcon Super D, and Topcon Super DM.

Topcon's 87-205 f/4.7 Auto-Topcor Zoom is not a thing of beauty, but it performs surprisingly well for a zoom of its era, and you can snag one for under $100..
Topcor 58mm f/1.4 RE Auto: The most acclaimed normal lens for Topcon SLRs is visually impressive with its massive front element, single coated on most versions, and its smooth turning, striated, rubberized focusing ring that takes the lens down to an impressive 45cm ( a little under 18 inches). Because of its longish normal focal length of 58mm (which gives 1:1 viewing) this is close enough for frame-filling head shots of kids, one of my favorite subjects. Based on a 7-element 5-group modified Planar design it delivers exquisite central sharpness at all apertures, superb definition across the field by f/4, and gorgeous bokeh at its widest apertures despite having a 6-bladed diaphragm that typically produced the dreaded “honeycomb effect” in out-of-focus highlights. Overall contrast is modest by modern standards, which helps to enhance its smooth tonal gradation, but it’s still high enough to make the images “pop.” The shorter focal length final iteration of this classic design is the RE GN Topcor M 50mm f/1.4 of 1973. Based on the same 7-element, 5-group optical formula as the 58mm, it’s multicoated, focuses down to 0.4m (15.7 inches) and provides flash guide number (GN) footage settings from 32-250. It’s a very nice lens, it’s radioactive (check out the B&H video online) but it’s bokeh is “busier” than the 58mm version. Yes, it’s a good, sharp lens but in my opinion, it lacks the character of the Topcor 58mm f/1.4 RE Auto, and it’s expensive—about $400-$800 0n the leading online auction sites. If you’re so inclined, you’re probably better off snagging a pristine Topcor 58mm f/1.4 RE Auto for $300-$500. It’s available in chrome or black finish (the latter at higher cost) and there are minor cosmetic variations mostly of interest to Topcon collectors more manic than I.

The "sleeper" of the Topcon RE Auto-Topcor line, the 58mm f/1.8 doesn't have the pizzazz of the big 58mm f/1.4, but it's a superb lens and more compact.
Topcor 58mm f/1.8 RE Auto: This 6-element, 5-group classic was the less expensive, slightly smaller alternative to the Topcor 58mm f/1.4 RE Auto and it also debuted in 1963 along with the Topcon R.E. Super. It’s the sleeper of the line, and were it not for its more glamorous 2/3 of a stop faster stablemate that provides a slightly brighter focusing image and razor thin depth of field wide open. the 58mm f/1.8 would be it would be the flagship normal lens in in the Topcor RE line. It’s a magnificent lens, exquisitely sharp wide open in the center, tack sharp across the field by f/4, and capturing smooth natural rendition, good contrast, and excellent tonal gradation at all settings. Like the 58mm f/1.4, it focuses down to 0.45cm (just under 18 inches) for frame-filling head shots, delivers gorgeous bokeh at its widest apertures, and focuses with commendable smoothness. You can snag one of these beauties in pristine shape for about $150-$200 in chrome or $300-$400 in black on the leading online auction sites.

The 100mm f/2.8 RE. Auto-Topcor is an outstanding portrait tele for film or digital imaging. This is the rare U.S. Navy version denoted with a red "N."
Topcor 10cm (100mm) f/2.8 RE Auto: A lens prized by collectors and users, especially those who adapt it to digital, this outstanding portrait lens introduced in 1965 is remarkably compact, is single layer coated, and features Heliar-type construction consisting of 5 elements in 3 groups. It’s extremely sharp even at f/2.8, with the corners coming in at about f/4 and it’s acclaimed for its smooth attractive bokeh in out of focus image areas despite having a 6-bladed diaphragm. Its contrast is moderate compared to current lenses, but its images can still “pop” while also retaining that rounded “vintage” rendition with long tonal gradation that many contemporary portrait photographers favor. The lens focuses down to 4 feet, close enough for head shots, but it does tend to flare in backlit situations, so a lens hood is recommended. The little Topcor 100 is beautifully balanced on any camera from a big Topcon Super D to a compact full-frame mirrorless, which makes it a great choice for handheld shooting. A pristine 100mm RE Topcor currently fetches about $250-300 in chrome, and the U.S Navy version marked with a red “N” commands prices in the $500-$600 range. It’s my second favorite Topcor after the 58mm f/1.4.

The 85mm f/1,8 RE. Auto-Topcor is a spectacular performer, but only about 1000 were made and it's now a rare and pricey collectible.
Topcor 85mm f/1.8 RE Auto: Introduced as a wide aperture medium tele for portraiture in 1973, this high-performance 6-element, 5-group lens focuses down to 0.9m (3 feet), close enough for frame-filling head shots, has a 6-bladed diaphragm, and weighs in at a moderate 16.9ounces. According to press and user reviews, it’s extremely sharp, the best in its class, and provides beautiful vintage rendition and smooth attractive bokeh at its widest apertures despite its (you guessed it) 6-bladed diaphragm. Thanks to its wide f/1.8 maximum aperture it’s awesome for creating artistic effects using limited depth of field. Regrettably I’ve never shot with one of these jewels, and I’d love to acquire one. However according to creditable sources only about 1,000 were made and collectors have snapped up most of them, resulting in online auction prices in the $2,000-$3,000 range, a bit too rich for my blood. I guess I’ll just have to content myself with my superb 1+ stop slower much smaller and lighter 100mm f/2.8 RE Topcor-

Topcon 20mm f/4 RE Auto is the widest lens possible given the narrow diameter of the Exakta mount Topcon used, but it's a magnificent ultra-wide equal to the best.
Topcor 20mm f/4 Auto: This 8-element, 6-group ultra-wide-angle masterpiece is a “radical retrofocus design” that was introduced in 1968 at the then very high price of $279.95. It covers a field of 94.5 degrees, focuses down to 1 foot, and stops down to f/22. Acclaimed for its extremely low linear distortion and crisp imaging, reviewers laud it as a “great lens,” but regrettably only about 1,500 were made so it’s relatively rare and quite expensive. Produced only in chrome finish and employing a dedicated clamp-on lens hood, it fetches about $700-$1,000 on the top online auction sites—if you take the plunge try to get it get it with the lens hood!

A 35mm f/2.8 doesn't sound exciting, but this RE. Auto-Topco is extremely sharp and well corrected, and delivers outstanding performance at a modest price.
Topcor 3.5cm (35mm) f/2.8 RE Auto: This outstanding moderately wide-angle f/2.8 employs an impressive 7-element, 5-grpup optical formula that delivers razor sharp images with low distortion and just a hint of vintage character thanks to its warm color rendition and moderate contrast. The corners come in at f/4, and it has smooth attractive bokeh (noticeable mostly in close-ups shot at its widest apertures) despite its 6-bladed diaphragm. It also focuses down to a commendably close 9 inches, which is great for nature studies and the like. It’s readily available in chrome or black at the relatively modest cost of $150-$300. Based on my hands-on experience it’s a winner.

58mm f/3.5 RE. Macro Auto Topcon is a true macro lens that gets down to 1:2 on its own but also delivers superb performance at normal focusing distances.
Topcor 58mm f/3.5 RE Macro Auto: Based on a 5-element, 4-group Xenotar-type design, this true macro lens gets down to 1:2 (10 inches) and it’s exceptionally sharp, has close to zero linear distortion, and virtually no off-axis light falloff even wide open. Indeed, its performance at infinity rivals that of most standard lenses, which greatly enhances its shooting flexibility. Since its front element is deeply recessed, a lens hood is not needed, and it can get down to 1:1 (life-size on film or sensor) with a dedicated or third-party extension tube. This gem is currently available all the usual places at $200-$350 in chrome finish and, and $500-$550 in black.
Obviously, there are many more Topcor lenses in RE mount that we couldn’t fully cover or review here, but you won’t go wrong with any of them in terms of their overall performance on film or adapted for digital capture. It is evident that the company acquired an incredibly sophisticated level of optical expertise by the mid to late ‘30s, and their intensive wartime experience in making optics for the Japanese Army served to hone the company’s impressive skill set. The ability to innovate quickly was another key part of Tokyo Optical Co.’s corporate culture. Indeed, by the late ‘50s they offered the gargantuan 300mm f/2.8 and hefty 135mm f/2 Topcor-R (pre-set diaphragm) lenses, which held the record for speed in their respective classes for many years.
If the amazing story of Tokyo Optical Co. reveals anything it’s the crucial importance of marketing in creating a brand image. While Topcor lenses were always as good as and often better than their competitors their marketing was not. Fortunately, we can still enjoy shooting with these optical classics now, and I can attest on the basis on my personal experience, that they’re bloody fantastic, have gobs of character and can capture truly beautiful images that stand the test of time.