Tag Archives: Topcor Leica Thread Mount Lens

The Leica Thread Mount Topcor 50 f/2

Topcor Leica Thread Mount 5cm f2

Weight: 9 ounces (255 grams)
Filter Thread: 40.5mm
Extension from Camera Body at Infinity Focus: 1.62″ (41mm)
Elements: Six elements in Four Groups
Minimum Aperture: F16, click stops

The Leica thread mount Topcor 5cm f/2 is considered one of the best normal M39 lenses of the pre-Summicron era. Some even claim it a match for the Summicrons of the 60s and 70s, at F5.6 and beyond on a par with the most recent versions of the Summicron. (It’s funny how much better Leitz optics are claimed to be unless of course, you’re selling a non-Leitz-made LTM, all of which apparently are “as good or better” than the Leitz version. I fall in with the “as good or better” crowd, finding the ’50s era Nikkors and Serenars typically more robust than that era’s Leitz’s and thus usually in better optical condition today).

Tōkyō Kōgaku Kikai K.K. (Tokyo Optical Company, Ltd.) was established in Tokyo in 1932 and started making lenses in 1935. Initially producing larger format lenses and lenses for the Japanese military, the company made LTM lenses after the War. These LTM lenses were first branded “State”, then “Simlar”, “C.Simlar” before “Topcor”. Topcor optics were considered fine optics back then. Topcon lenses were sharp, indicating a high degree of optical design skill, and build quality was good, on par with ’50s era LTM lenses from Japan and Germany. Mechanically it compared to the LTM Nikkor-s 5cm f2 and to Canon LTM lenses. My early production chrome “Topcor 5cm f/2” (no “s”) came attached to a 1956 Leotax F and has the look and feel of a typical ’50s era fast prime. It’s beautifully machined heavy chrome.

A 1956 Leotax K With the Chrome Topcor 5cm f2

The Topcor 5cm f/2 was sold with the Leotax series of rangefinder cameras from 1956 through 1961, available on the F, T, K, FV, TV2, and T 2L models. They don’t appear to have been sold separately from the Leotax. Early models were chrome, later models black: in 1956 the chrome Topcor f/2 5 cm lens appeared, replaced by the new chrome Topcor-S f/2 in 1957 and updated to the black and chrome panda version in 1958. A black aluminum barrel version was released in 1958. When the Leotax G arrived in 1961, its lens offering was a black Topcor-S 5cm f/1.8. (This new Topcor-S f/1.8 looks similar to the aluminum-bodied f/2, including the 6 elements in 4 groups optical design, 10 aperture blades and 40.5 mm filter thread, but the front elements are noticeably different). All versions of the f/2 feature an optical design of 6 elements in 4 groups, 10 aperture blades.

It’s unclear how many 5cm F2 Topcors were made. It’s uncommon to find them these days. Although maybe 25,000 Leotax’s were produced between 56 and 61, I assume many were purchased with the slower speed Topcor 5cm f3.5, a few more with the expensive 5cm 1.5 ( the 1955 brochure for the F’s introduction lists the 1.5 and the 3.5 5cm as the standard lens options). Undoubtedly many more have disappeared over the years, stuffed in old boxes in attics or simply thrown out as junk. Both the chrome and black Topcor 5cm F2 appear for sale on eBay from time-to-time, usually stuck to a Leotax body at relatively cheap prices. Sold separately, they command a premium price. Makes no sense, but then again, nothing about vintage rangefinder pricing makes sense.