Wow what a lens! Review of a top-rated concave glass classic: Carl Zeiss Ultron 50mm f1.8. 

I’ve been using a Tessar zebra on m42, maybe from these? But it’s fast becoming my favourite lens..that is until I took it to Pompeii and it fell apart on the way! I just put it back together though ;)

Many thanks this. I have noted your comments and will re-read them often. Sadly I've always struggled with pronunciations and spelling (I prefer visuals), and your advice is very welcome and well received. Cheers.

thank you ; I was quite apprehensive you might take it the wrong way ; it is in my nature not to hide light under a bushel ; this one may amuse you ; I was living on the I.o.W and every now and again I had to travel to the big city of sin on the account that the British Library & Museum were there ; one day I had to do someone else's bidding and visit a TV studio ; there , quite by accident I met two commentators from British Eurosport ; my most ardent question , since childhood , was how do they switch from commenting on TV to commenting on radio ; they were kind enough to indulge me ; I could not help noticing how consistently wrong they pronounced foreign names ; gave them a few names to pronounce and , obviously they got it wrong ; told them the golden rule , if naturally you stress a syllable , stress the other one ; can't go wrong this way ; we was at the second cup of tea , fags were puffing and it hit me ! papers and pen please ; I took them from Norwegian to Suomi ( Finnish ) ended up in Spain , went eastwards 'till Romania , every country and it's language ; they took notes , I made a sort of a pedantic cheat sheet ; alright mate they said , less go for a pint ! true , they had their pints and I orange juice , coz I was at the beginning of my sober period ; to this day they 'phone me on Christmas Day ..........cheers ! once again I do very much appreciate your photographic Weltanschauung .

All the Ultron 50mm lenses made by Voigtländer before the end from the Voigtländer factory at Braunschweig in 1972 were designed by Dr. Tronnier. He also designed the Nokton 50mm/f1.5. The Nokton 50mm/f1.5 and the Ultron 50mm/f2 were first introduced with the Voigtländer Prominent. Later the Ultron 50/f2 was available on other Voigtländer cameras you are listed above and the Vitessa as a fixed lens. The Ultron 50/f1.8 was also designed by Dr. Tronnier and it was the only lens which were designed for the Icarex. All other Icarex lenses were older Voigtländer constructions from the Ultramatic and Bessamatic relabeled as carl Zeiss lenses. Greetings from Germany too.

@@Hasenvater64 So the comparison with the Vitomatic Ultron lenses is not so far-fetched 😉

Great question! I will probably be keeping this lens as long as I do these reviews of old lenses - individual lenses and groups of lenses. It's a good "benchmark" lens, for all it's pros and cons. I now own a number of lenses I don't use for my personal enjoyment/tastes, and would like to sell, but I feel I need to keep them in case I need to involve them in a video. Plus, my argument at home (where space and dust are issues), is that these lenses are appreciating assets, unlike cash, and can always be sold in the future if cash is needed.

I attempt to make that same argument at home, with somewhat varied results. My 3-year-old seems to agree, but the non-me adult remains unswayed...especially when it comes to all the ancient digital cameras in addition to the lenses.

Not really, just a different aesthetic.

Many thanks. No, the Helios 44-2 are not radioactive.

Yes, in fact I refer to that specific lens (the Schneider-K....SL Xenon 50/1.8) in the video and say it's sharper wide open than the Ultron. I think it replaced the Rollei branded Planar f1.8 on Rolleiflex 35mm cameras.

@@Simonsutak By the way, i enjoy all of your lens review videos.

Thanks, you reminded me to start that video. You're right, I was thinking of a QBM lens (a f1.8 lens, not the Voigtlander, but the cheaper Rollei!!).

I can confirm with some degree of certainty that the color-ultron is the same lens as the Rollei/Zeiss planar 50mm f1.8 (with or without HFT, made in Singapore or West Germamy). The lens design is apparently based on the Zeiss Ultron kindly reviewed by Simon but tweaked by the legendary Erhard Glatzel, designer of famous lenses like the Pentax K/Zeiss/Rollei “Hollywood” Distagon 28mm f2. (M42 spiral and Marcocavina have more information relating to the parents, lens diagrams and sample photos) The reason the lens exists in many names seems to be because the Ultron did not sell well. Commercially it was unfortunately a failure like the Contarex that preceded it. It was just unable to compete with the more capable and cheaper Japanese competition. Zeiss, Voigtlander and Rollei were, with some aid and involvement from the German government (Zeiss official history page has more info) forced to join hands to create the Rollei SL35 series with the new lenses. The premium lenses were either newly designed from scratch, carried over from the Contarex or Icarex line-up or redesigned. The budget options were called Rolleinar MC and made by Mamiya Sekkor in Japan. I trust this is the 55mm f1.4 referred to which was also branded “Voigtlander Color-Ultron AR 55mm f1.4” Due to cost reasons the Rollei/Zeiss line-up seemed to be replaced with a budget Schneider-Kreuznach line-up which included the equally sharp Xenon 50mm f1.8 mentioned by Simon. (olypedia.de is the only place with the full lens catalogue I could find) It seems production of the Rollei/Zeiss was originally in Germany but moved to Singapore to 1971 to compete with Japanese competitors after, it is said online, an explosion at the German production facility. While some internet sources say the Rollei Planar was modified to reduce production costs, compared with the Zeiss Ultron, images from the Rollei Ultron seems to be as sharp if not sharper but more contrasty and vibrant albeit with digital it suffers from some purple fringing. The Zeiss ultron seems to occasionally suffer from cyan hues and muted colours due to the glass selected and the lack of the later HFT coatings (said to be similar if not identical to later T* and contemporary Pentax SMC coatings) Note that this lens formula is not the same as the later Contax 50mm f1.7 which some say is a further improvement and is actually more similar to the Contax/Rollei 50mm f1.4 designed by Erhard Glatzel. The Rolleinar MC 55mm f1.4 uses the expired patent of the Contarex 55mm f1.4 as Zeiss updated it’s design as the Rollei/Contax 50mm f1.4. This is indeed a fine lens and performs like images of the Contarex and Pancolar 55mm f1.4 or their Japanese copies by numerous manufacturers I’ve seen online. But I don’t think it’s the sort of lens I would describe as a must-have as it doesn’t blow me away particularly as indeed many contemporary Japanese 55mm f1.4s use a similar if not identical formula. Apologies for the long read but it's a complex story that’s sadly disappeared to the dustbin of history that I myself took some time to uncover online, even in more than one language! I hope this was useful/interesting to you.

@@trevoyelliot2193 Many thanks for this extremely interesting and helpful post. A really enjoyable read. I've compared the Carl Zeiss Ultron f1.8 with the Rollei HFT f1.8 Planar and wide open it's hard to tell the difference. (I don't own a Voigtlander Color-Ultron). The Rollei Planars seem to suffer from build quality issues, especially with their aperture mechanism. But the optical quality and coatings are good! Curiously, I was playing with a Zeiss Ikon Contarex Bullseye camera and a beautiful f2 Planar yesterday at a camera fair, but I just couldn't justify purchasing it. Maybe one day!

​​​​​@@SimonsutakGlad that it was helpful and wasn’t too onerous to go through. Despite being an intermediate for Zeiss between the pure German Contarex and the then increasingly Japanese Contax-Yashica system after Pentax chose not to make lenses and cameras for Zeiss, it seems the daunting reality of a Japanese dominated camera market ensured that the best of West German optical engineering was crystallised in the Rollei system. All lenses in QBM mount are regarded as sound if not superb and I suppose this is why owners in the Chinese circle particularly, who have been more vocal in sharing their experiences say they have a love-hate relationship with the mount. Chan nds hk for example compared, in Chinese, the budget Rolleinar 21mm f4 and he concluded it was better for colour photography on digital than the Leica Super-Angulon-R 21mm f4 and cost performance wise was probably better than the Leica and the Zeiss Distagon 21mm f2.8 I do agree the QBM mount is not an easy mount to use. The later lenses with rubberised rings are best suited by a QBM specific adapter that firmly pushes the pin in to set the aperture in place. The earlier made in West Germany lenses with metal rings have an Auto Manual switch so they don’t have the issue. I personally use a QBM to Leica M adapter, then use the LM-EA9 adapter to achieve some autofocus and focus confirmation on my E mount cameras. So it’s probably easier to simply adapt Contax/Yashica lenses given they inherited identical if not updated lens designs and construction made by Zeiss or Tomioka, owned by Yashica and later Kyocera, with a more capable camera with Japanese electronics, which is also reflected in the price. Indeed it seems for West German Zeiss developed systems, apart from the excellent K mount used till today, some quirkiness with the lens mount or camera is a common theme. Unlike the Contax versions, the QBM Distagon 35mm f1.4 and Planar 85mm f1.4 for example have triangular bokeh that are quite the acquired taste. The Contarex system is also a pain to use I understand with the very unique setup and astonishing if not insane price tag at the time and even now. I also shared your agony in the inconvenient lack of common filter threads or hoods for the Zeiss Ultron. I personally found a Ultron Lens 55mm Filter Adapter from China which slots into the bayonet flitter thread and allows the use of conventional 55mm filters and hoods. There’s an alternative which screws onto the silver threads at the front. Both seem to be available on eBay or alibaba should you require one. As for the Contarex system, that is personally unappealing to me. While it is exquisite as a collector’s item and a handicraft, I too can’t justify purchasing a clunky “bulls eye” camera with a 50mm f2 lens that doesn’t really stand out from the competition. It definitely isn’t the best standard lens ever made. It’s a fine lens for sure but the Pancolars, Ultron, Takumar 50 1.4 or 55 /lenses or Rollei Planar will likely outperform it. Philip reeve’s informative review showed its bokeh isn’t particularly special or eye catching compared with even a Minolta MD 50mm f2. I guess as Marco Caniva showed, since the Contarex planar is essentially a modified Biotar designed around 1953, as the Biotar name was allocated to Jena in 1953 after lawsuits settlements between East and West Zeiss, it does not stand out particularly from the Jena lenses of the period, and as Jena was the hometown of the original Zeiss where most R&D was done until the end of the war before the division of Germany and not the relocated West German Zeiss Oberkochen, Zeiss Jena is said to have lead lens innovations and technology until around the 1960s anyway under the immensely able Dr. Harry Zöllner. (The excellent zeissikonveb de has more on this subject) I hope this is helpful and not too long/boring to through and thank you Simon for the ever informative and intriguing reviews of the famous and occasional rare and curious vintage and sometimes modern lenses. It’s always a pleasure to see your reviews and it definitely helped me pick some fine lenses when I started using vintage lenses a few years ago.

I sympathise. I sometimes wonder (without any empirical evidence) how accurate the Sony a7 cameras' electronic viewfinders are when using the magnified focus. Right now I'm testing another manual focus mirror lens, and it's proving to be very difficult to nail the focus. My solution is to do something like manual "focus bracketing" - moving the focus ring to where it looks like its in focus zoomed in on the viewfinder, take a photo, and then very slightly move the ring to the left and take another photo, and then back a little more to the right and take a third photo. But that's a chore!

I would like to do that! Do you have an idea of what I might find out?

@@Simonsutak yes, I think that the sharpness, bokeh and colour, in short the IQ of the Planar is better but as you know very well, it’s partly a matter of taste. Zeiss list their “Classic” line up on their website but it’s difficult to find a new one from their list of authorised dealers. Mostly it’s second hand. I did give Zeiss UK a call and they very helpfully recommended a retailer for second hand, so now I have a Planar and an incredible Otus (1.4/55) for Nikon, for comparatively little money.

The ergonomics for the aperture is interesting, and made me smile! When I borrowed the M42 lens, I really didn't like aperture ring. It felt too loose. (Normally I like click-less aperture rings). And I kept confusing the aperture ring with part of the body with ridges just behind the ring. But (and this is a big), after using my copy of the lens - same design as the M42 - I started to get used to the aperture ring, and found the "handles" on the side were very helpful. I actually started to like it, and the click-less touch. I talked about all this in my first draft of the video, but decided to knock it out! On "heavy vignetting wide open", I don't see this on my bayonet-to-Sony camera gear. Maybe it depends on the camera used?

@@Simonsutak Exactly. Even worse is that it is easy to hit/move the protruding handles on the aperture ring, and suddenly the exposure is very different from what you had preset it to. Re. vignetting, I shot into a blue sky adapted to sony e-mount apsc size sensor. So one would expect less vignetting because the lens covers much more than the sensor, but it was the worst vignetting I had ever seen on any camera or from any lens.

Not yet. I've been using a 5.8cm f1.8 for a while now, and I've recently acquired a 58mm f1.4. So I will be reviewing one or both. Not sure when.

@Simonsutak I have the 1.4, really fun. Same with the 35 & 135 copies. Look forward to your take. Stay safe.Peace

I don't know if the Contarex is better as I haven't tried it. But it does have a good reputation. Looking at photos on line from the Contarex, I'm not sure there is a huge different at f2 between the two lenses. Stopped down I personally doubt the Contarex is better, perhaps similar performance. But maybe the Contarex has better edge sharpness? Both are "collectors" lenses I feel, as there are better value for money alternatives.

I've been pleasantly surprised by the TechArt Pro LM-EA9 autofocusing adapter for old prime lenses like these. Of course it's not comparable to modern natively-autofocusing lenses, but it's still pretty good as long as you have a Sony MILC with PDAF.

@@Badgerheist DJI also made a LiDAR supported autofocusing "adapter". Supposedly its better than normal AF but it adds much more bulk and $$$

I understand the new Sigma 50/2 DG DN also has a concave front element.

​@@Simonsutak The Sony 50mm 1.2 and 40mm 2.5 are both concave (i feel like the Zeiss 55 1.8 looks concave, but i could be wrong). I didn't realize that there were such early concave lenses!

It was the first. It is said to have came out of a pub bet between Tronnier and someone I do not remember. That someone said, "I guess it is impossible to build a lens with a concave front element." And Tronnier said, "hold my beer."

Sapphy . Sapphy's a ragdoll cat.

@@Simonsutak beautiful. I had two Main Coon..similar in beauty and silliness!

@@Simonsutak I've enjoyed your videos immensely..I was a die hard film only guy but the blend of vintage glass and digital sensor seems to work for me. Luckilly I had a few interesting m42 lenses in storage from my years of Berlin fleamarkets..I had everything once! 1euro per lens back then!

I think it can depend on the scene you're photographing, and your camera settings. I own some lenses that really don't render out of focus areas well at all (including new lenses)...but with the right background/foreground, the bokeh can look rather beautiful. The point I was trying to make is that to dismiss the Ultron for poor bokeh all the time is not totally "fair".

@@Simonsutak I know that you didn't dismiss it for poor bokeh all of the time. It amazes me that lenses people buy especially for bokeh can also give them such mixed results. I remember reading Nikon lens reviews where a lens was sharp, had speed but also poor bokeh. There were tradeoffs when new lenses were presented. Even now.