High-quality tele and tele macro lenses are still the one thing missing from the native Micro Four Thirds lens lineup. For now, quality stops beyond the Olympus 75/1.8, there’s only a great number of consumer telephoto zooms beyond that focal length. So, out of curiosity and also because I’d sometimes like to use a telephoto macro lens, I just bought a Carl Zeiss Jena 135/3.5 Sonnar and gave it a try on my E-M5.
There is a number of great Carl Zeiss Jena lenses out on the market, but sometimes they seem to be a bit over-priced for what they are. Still, the optical formulas of some of these lenses – such as the 35/2.4 Flektogon, the 50/1.8 Pancolar and this 135/3.5 Sonnar – have a very good reputation. And the prices are still much lower than for modern AF lenses. At one point, I had any of these three lenses and they all performed really well. But on a Micro Four Thirds camera, the only one out of them that’s really interesting is probably this 135/3.5 – why would you use a 50/1.8 Pancolar or a 35/2.4 Flektogon when you can have the much more convenient and excellent Olympus 45/1.8?
The Carl Zeiss Jena 135/3.5 Sonnar is the successor of the older 135/4. Production started in the late 1960s, first with the older “zebra” style barrels which were later changed to the more modern all-black design. After the shift from the older 135/4 to the 135/3.5, the optics would remain the same until the end of production at the late 1980s / early 1990s, save the MC multicoating that appeared from 1976 onwards. Whereever the 135/3.5 was tested or reviewed on APS-C or 24x36mm DSLR, it fared really well. A good review can be found at SLR Lens Review.
What it can do on Micro Four Thirds
On a Micro Four Thirds camera, the 135/3.5 acts like a 270 mm telephoto lens would on a traditional 35 mm film camera. Get yourself a matching M42 adapter for your own camera, and you can use this lens right away. It can be near focused to 1.o metres (object to sensor distance), giving a magnification ratio of about 1:5.2 with an image area of about 68×88 mm – good for big butterflies and dragonflies without any extension tubes. Incidentally, the Panasonic 45-200 focuses to the same distance and gives 1:5. You have to set it to 200 mm to match the 135/3.5 at close focus. This is pretty normal for today’s zoom lenses with internal focusing.
Here’s a not-too-scientific series of shots from f/3.5 to f/8. I’d say that between f/3.5 and probably around f/5, you clearly see how lens performance and sharpness improve as the aperture is closed. From then on, it’s more a question of depth-of-field than anything else. One thing that I noticed is that manual focusing is really hard, if you really want to make sure you’re 100% spot-on. Switching to the screen loupe and then using focus peaking would be the best – but there’s no Olympus camera that offers focus peaking yet.
(All images were shot on a tripod with remote flash lighting. The RAW files were developed with Adobe Lightroom, using standard sharpness settings.)
At maximum magnification on the E-M5 screen, I noticed that there is not a single exact focus point as the lens exhibited some sort of astigmatism (my not too well-educated guess). You can see how very small details are elongated a tiny little bit and how the direction of this elongation switches roughly 90 degrees when you go through the focus point. I’ve seen similar things happen on astronomical telescopes with astigmatism. Probably a more scientific test could show if my guess is right or not. In practice, it just means that stopping down a bit is required to get rid of this error. I am very sure you’d never notice this stuff on a Canon 6D, for example. But the high pixel density of the Micro Four Thirds sensors shows small optical errors like this more clearly. This ain’t no modern Leica lens.
Here are two comparison shots taken with the Panasonic 45-200 at f/5.6 and f/8. At this distance (about 1.5 metres), the Panasonic had to be set to 175 mm to yield the same field of view. Contrast is a bit better on the Panasonic, most likely because of the more modern coatings. But the images are clearly less sharp and less clean than the 135 Sonnar, especially around the image borders. I also noticed that both the foreground and background look a bit harsher but also more blurred than on the 135 Sonnar shots at corresponding aperture settings. I have no idea why – probably there’s a slight variation in the actual aperture compared to the EXIF readout. Or just something more esoteric going on. :)
At this point, I’d say that the optical quality of any one of the better old 135s is sufficient to use it for high-resolution images with a Micro Four Thirds camera. Okay, you already knew that, didn’t you? What surprised me, though, is just how easily this sample of an old lens surpassed the modern zoom with regards to image quality.
The image quality of the 135/3.5 on the E-M5 chip is good, but not flawless in any way. Stop it down to about f/5 and the quality for close-up shots should be really good, though. I haven’t tried it at infinity yet.
My much bigger concern is how easy a lens like this will be to use under everyday shooting conditions – hand-held, with probably moving subjects and manual focus only. You can set up your E-M5 such that the image stabiliser is active when you half-press the shutter button. This helps a great deal with focussing! But, overall, I guess here the old saying goes for anyone of us…. your mileage may vary!