Topcor 50mm f/1.5

Tokyo Optical Co. Topcor 50mm f/1.5 LTM (Semi-Sonnar) Mini-Review

This Tokyo Optical Co. (Topcon) Topcor 50mm f/1.5 ltm is a bit of a rarity. It’s also something of an oddity inasmuch as it has been described to me by Perry Ge (off of the Classic lenses podcast) as a “half Sonnar half Gauss design” and is a lens that shouldn’t work, but does.

This particular Topcor 50mm f/1.5 ltm was loaned to me by Will from The Latent Image. I’ve been following his shop on Instagram for a while – there is often something that gives me a bit of GAS that pops up in their feed.

That said, so far I’ve been good and haven’t bitten yet, though I did make things a little bit more dangerous for myself by making first contact with Will the other day suggesting that I will pop up sometime soon. His shop is only in the next county, and there is another camera shop I’d like to visit not far away that would make a nice little pilgrimage round trip for me…

Anyway, I digress, after contacting Will the other day, it wasn’t long before he chose to wave this little Topcon 50mm f/1.5 under my nose. I’m about to buy something else that’s going to hurt a little, so fortunately for me, I was able to resist. But, resist as I might, it wasn’t long before we were talking about a short loan for the sake of this mini-review.

I’m actually not entirely unfamiliar with Topcon lenses. I also have a later 50mm f/2 that’s currently being tinkered with by Chris Andreyo. The f/2 lens is decidedly more common than the f/1.5 lenses, though still quite unusual in the fact that it’s based on a Biotar design.

I say Topcor 50mm f/1.5 lenses (plural) as there’s actually two versions of this lens. When I initially contacted Perry Ge to see what he knew about it, it was in fact the other version, the ‘Simlar’, that he assumed I was talking about. The Simlar apparently has an even more out-there character than the version I have here. Though the non-Simlar is slightly less common – or at least Perry has seen less of them in the wild.

When I asked Perry for more details, he told me that these lenses come from an interesting period in Japanese lens design history. After the German patents were overturned as part of the war reparations, the Japanese first started copying the German designs, then before settling into more normal designs of their own, there was a time when they tried a few more whacky ideas. In Perry’s words, “Nothing about this lens design makes sense, but somehow it works”.

To a lesser or greater degree, I have to take his word for all this as I am not blessed with the ability to read lens formula diagrams. Though he did send me a screen grab of one from this page which shows the two versions at the top. You can also find more info on this page of the same website that contains some useful/interesting information about the lens – just beware, google translate does not do the content justice…

Of course, as you might know if you read my reviews, this historical stuff – interesting though it is – is not really my bag. I’m mostly interested in how the lens feels to use and the pictures that come from using it.


Another lens I own from this approximate era is the Sonnar Type Canon 50mm f/1.5. That is a lens that is a beautifully built. It’s probably the heaviest, most solid feeling, most satisfying to use lens I currently own. This Topcor 50mm f/1.5 is right up there with the Canon. By comparison with my near-perfect Canon, the focusing just feels slightly more its age – though, there really isn’t much in it at all.

The weight, quality of build and material feel of the Topcor 50mm f/1.5 is up there with the Canon too – it’s clearly made out of brass. Even the aperture – which is clicked – rotates with satisfying smoothness between clicks like my Canon does.

The difference between this 50mm f/1.5 and my Canon though is that whilst the optics on my Canon are a bit duff, the optics in the Topcor are lovely! I can barely see any cleaning marks, very few tiny dusts, and there’s certainly nothing horrible inside. But the really surprising bit is that the body work is also nigh on perfect too. Sometimes I behold lenses like this and wonder how they have survived in such good condition…?

As I talk about in my Canon review, that lens is perfect on the outside, but crap in the middle. This is probably why it’s looks so good. It probably wasn’t used much because of its optical failing – not that it’s visible in the results mind – but just that the separation that it has suffered might have people off using it. That’s not the case with this Topcor 50mm f/1.5. It’s lovely on the outside and inside.

The photos

I only managed to take the Topcor 50mm f/1.5 out on one shoot – Will wanted it back for the weekend so he could shot it himself before it sold. As such, there’s not a huge amount to see here, but hopefully I’ve taken enough images to give you some clues to the sorts of results that come from using it.

Results from this lens are just as interesting as you might hope from a lens that is supposedly half a Sonnar and half a Gauss. I really didn’t know what to expect, but it had me intrigued at the first photo I took.

I was really taken aback by the “sharpness” centre frame, but whislt zoomed in on the back of the camera I also noticed that despite this central sharpness – even stopped down to f/8 – it falls away to the edges/corner. I suppose this is a product of the Sonnar bit of the lens…? Have a look at the bottom right corner here:

Topcor 50mm 1.5

Of course, the next thing I did was to attempt to investigate bokeh with some shots of some apples.

Topcor 50mm 1.5

Topcor 50mm 1.5

Quite pretty I thought, though I also thought I could just detect a little bit of a wiry look to the bokeh toward the edges of the frame. As such, my next trick was to point the lens at a leaf with some more leaves and sky in the background. Boring images, I know, but they do highlight the look of the bokeh given this type of background.

This is f/1.5 vs f/2. As you can see the bokeh calms down a fair bit when stopping down a little, but there is something of a cat’s eye effect with harder edges to the highlights toward the edge of the frame. I suspect this would create something of a swirly look given the right camera/subject/background distances.

You can see it a bit more here too:

Topcor 50mm 1.5

Wide open, the area of sharpness closes in to the centre of the frame. This means shooting off centre subjects wide open gives the subject a bit more of a glow. That said, you can see the subject is still quite sharp – or at least not out-of-focus – through the glow. As such, I don’t think there is too much in the way of field curvature here – it’s possibly just spherical aberrations that as causing it to not be as perceptibly “sharp” into the edges/corners. I might be wrong…?

Topcor 50mm 1.5

In these next images, you can really see the sharpness and contrast centre frame – the bricks of this old stable have stacks of detail.

Topcor 50mm 1.5

Topcor 50mm 1.5

And again in the back of the tractor here – the lens has good resolving power, and is fairly contrasty – stopped down at least.

Topcor 50mm 1.5

Wide open, there is definitely a reduction in contrast in images from the Topcor 50mm f/1.5. Though, this is not without merit – I was really taken with the look of this next image. The subject has a nice glow, the bokeh is interesting, there’s a bit of a vignette that I like. All in all, it has a nice look to it, I think.

Topcor 50mm 1.5

I got a couple of other images I quite like too. I think the following few images were around f/2.8:

Topcor 50mm 1.5

Topcor 50mm 1.5

The detail in the leaves is really quite nicely rendered I think

Topcor 50mm 1.5

I really like this next one. You can just see a bit of that swirlyness in the background, and the grass that’s out of focus in the foreground is really nicely rendered, I think.

Topcor 50mm 1.5

And this last one was stopped right down again – the sharpness, contrast and colour is just lovely.

Topcor 50mm 1.5

I meant to try and force this Topcor 50mm f/1.5 to flare, but unfortunately I forgot. It would have been interesting to see how it got on with some direct sunlight.

All in all though, I must admit, I found myself a little smitten with the results. It’s certainly different to the Sonnar lenses I am most readily found with – I don’t prefer it – but perhaps because I managed to achieve a good few photos that I find aesthetically pleasing in such a short amount of time… well, it did nothing for my GAS, let’s put it that way…

Topcor 50mm f/1.5 – A collectors lens

That said, it wasn’t enough to convince me to part with my cash. I love the results, and the handling – it’s a lovely package – but this Topcon 50mm f/1.5 is really a collectors lens. It’s too just much for me – it’s too clean, it’s too mint, and at something around the ~£1500 it’s worth, it’s just too rich for me too. It’s the sort of kit I would be scared to own.

This is a lens for someone who likes to have rare and unusual lenses in their cabinet that’s in spot-on condition. For someone like that, this lens would be a real treasure, I’m sure! I do hope that whoever buys this Topcor 50mm f/1.5 shoots it though. It might be a collectors thing, but for how nice it is, and how unusual it is, it definitely deserves to be shot with!

If you are interested in this lens, or more interesting film cameras and lenses, it’s definitely worth adding The Latent Image to the list of websites you peruse. His instagram is well worth a follow too

Thanks for the loan, Will!

Contribute to 35mmc for an Ad-free Experience

There are two ways to experience 35mmc without the adverts:

Paid Subscription - £2.99 per month and you'll never see an advert again! (Free 3-day trial).
Subscribe here.

Content contributor - become a part of the world’s biggest film and alternative photography community blog. All our Contributors have an ad-free experience for life.
Sign up here.

About The Author

20 thoughts on “Tokyo Optical Co. Topcor 50mm f/1.5 LTM (Semi-Sonnar) Mini-Review”

  1. I looked at the schematic you linked to Hamish. Then looked again. Then stopped looking as it was doing my head in. S’very very strange. Beautiful looking though, and it looks like it will ‘pop’ with the right combination of highlight and vignette. I hope it gets used. £1,500? A snip for a Leica dude.

    I enjoyed that. Thank you.

  2. An interesting lens, with somewhat different rendering. I’ve never heard of this lens before, but this article has inspired me to look into its cheaper f/2 sibling to see if it shares any of this lens’ traits

  3. Very interesting, thanks for this as Topcor lenses don’t get too much coverage. My first Leica fit lens was a Topcor S 5cm f2 , still possibly the best made lens I have. Unashamedly dense , smooth, satisfying in the hand and top notch optically.

      1. Yes , it’s the all silver version , solid bit of kit , it came attached to a Leotax F , its aperture ring has delicate click stops and the focus is ultra smooth. It looks pretty similar to this 5cm f1.5 you have here.

  4. The Topcor LTM love in this comments section warms my heart. Those lenses don’t get the credit they deserve, though that’s probably for the best as it stops the prices from getting jacked up too much! Great review.

  5. There is surprisingly little information on the web about Topcor lenses (or at least I could not find much). Are their ƒ/2.8 lenses versions of the Tessar design? I am tempted to try one.

  6. Hi Hamish, I have had a good look at the 5cm f1.5 Simlar formula in Japanese collector magazines and it’s almost certainly a modified Biotar/Planar formula. The name is even a giveaway Simlar/Biotar, you see? If you look a the formula in this article … you can easily see that the three front elements are identical, and the rear element has been slightly modified, but only marginally. Sorry to burst your bubble, I know how much you love a Sonnar; but in this case the lens has to go into the Biotar pile mate 🙂

    Tokyo Optical Co. (aka Topcon) were part of the group given German lens patents when Hitler signed the Axis Pact in 1940, and used these patents to design their Post War lenses.

    1. Useful info! But yeah, ????‍♂️ take it up with Perry. He’s who fed me the sonnar stuff

      And as I said in the article, “It’s certainly different to the Sonnar lenses I am most readily found with – I don’t prefer it – but perhaps because I managed to achieve a good few photos that I find aesthetically pleasing in such a short amount of time…”

  7. A guy I know gave me a bunch of photographic odds and ends from his garage telling me to use the, sell them or dump them and among the stuff in there were three old C-mounts that look like TV lenses and this Tokyo Optical 50/1.5 Simlar. I got excited thinking it was an early Nikon lens and shot it despite the heavy scuffing on its front element. I fell in love with its rendering and a few days later decided to lightly clean that front element.

    To my surprise, it was just dirt! It cleaned right up. And that lens has since been grafted to whatever Leica I happen to be shooting. Such a lovely lens!

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top