Meet the Lens: Canon Serenar 50/1.9

Some lenses are almost universally loved, others are not. Advocates of the latter tend to speak of “character” instead of more easily quantified measures like resolution, lack of distortion, and such. The Canon Serenar 50/1.9 which I recently acquired falls into the “character” category.


The 50/1.9 was one of the earlier Canon rangefinder lenses, and like many early efforts was largely copied from existing designs; in this case, the Leitz Summar and Summitar (both 50/2) were the inspiration. The Serenar shares the basic collapsible design of the Leica lenses. The clickless aperture scale only runs from 1.9 to 11, with a little extra beyond the 11; this, along with the round (vs. hexagonal) aperture, would seem to suggest that the lens they copied was an early Summitar that had the old-style aperture scale ending in 12.5. Pure speculation on my part, but it would appear plausible.


Optically, it’s a double-gauss arrangement of six elements in four groups, similar to the Summar (the Summitar has seven elements in four groups). Unlike the Summar, however, the Canon lens is coated and the glass is hard enough that there’s a good chance it won’t be badly scratched (unlike the Summar or early Summitars).


Based on early efforts to build faster lenses (the Summar originated in 1932), it’s not surprising that the Serenar shows its age. There’s some field curvature, the corners get pretty soft at larger apertures, and out-of-focus areas can get a little wild and swirly wide open. No one is going to mistake it for a modern lens. Stopped down, though, it’s plenty sharp across the frame.


It hasn’t shown much tendency to flare except when pointed directly at a light source, but I’m a big devotee of lens hoods for protection as well as contrast, so I planted a nice little aftermarket one on with a 40-40.5 step-up ring – no intrusion into the viewfinder, and no additional vignetting.

I’m really enjoying it so far. I love the ability to go from crazy wide open to sharp stopped down without changing lenses, and the glow it produces when opened up makes it really nice for atmospheric night street shooting. I’ve said it before and I’ll say it again: perfection is overrated.

8 thoughts on “Meet the Lens: Canon Serenar 50/1.9

  1. Thank you for this great review. I’ve just bought one as well as a leica IIIF, but unfortunatly it does not seem to collapse fully into the body. Are you aware of such an incompatiblity ?

    1. Mine collapses fully on my IIIcs and IIIg, so I suspect you have a problem with either the lens or the body. Does the lens fully collapse off the body? Take a look inside the body from the front. There are several light baffles in there that could come loose if improperly assembled; one of those could easily block the lens barrel if it ended up bent or out of place. Also, collapse the lens slowly; there aren’t too many places for air to escape from the body quickly, and pushing the lens in can generate momentary air resistance if done so too fast.

    1. Well, it’s good that you figured out the problem, but not so good that the lens is bent. How exactly is it bent? It seems really hard to bend the barrel – is it a part of the mount that’s damaged? Depending on what’s wrong, it might be easily repaired, or it might be junk. If you can post a photo or two I might be able to give you some feedback on it; I’ve been inside mine, so I know how it goes together.

    1. Yep, it looks like the barrel is bent in relation to the base. Not sure what your comfort level is, but if it were me I’d take the lens apart and see if I could identify exactly what is bent. You might be able to determine where the problem lies just by examining the locking end of the barrel with the lens collapsed. Repair will probably be tricky business, but you don’t really have a lot to lose.

      As for using it as it is, I think you’ll see a very uneven focal plane, with one or both ends of the photo being out of focus. It might work OK at small apertures, but even so I’d expect some distortion. I’ve had old folders where the lens was off-square by about a millimeter, which produced softness on one edge. This looks like it might be more pronounced.

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