#84. The Zeiss ZM Distagon 18mm/4 on the Sony NEX-5N

UPDATE : A summary of all this website’s reviews of the Sony NEX-5n and NEX-7 is now available.

As the Sony NEX-5N and NEX-7 progressively ship to their long-suffering owners, interest in legacy lenses is rising considerably. The focus peaking feature on these cameras is, too my mind, better than any autofocus I have ever used and easier with long lenses than rangefinders. And the variety of adaptors produced by Novoflex, Kenko and others opens-up new avenues of testing and digging out old favourites from the film era hidden in a closet for years 🙂 For those who are interested (and you should be ;)) Andrea, from SonyAlphaRumours, has recently started a survey of how such legacy lenses work on the NEX-5N and NEX-7. Please submit information to him if you have any.

In a recent post, I tested the NEX-5N with a slew of manual lenses from Leica and Zeiss. In one of the comments, fellow photographer Philippe kindly offered me to test some of his (impressive) collection of lenses. One of which is the Zeiss ZM Distagon 18mm/4, which I have been longing to use as it is a much smaller (and convenient) proposition than my excellent but bulky (and requiring a different adaptor) Leica Elmarit-R 19MM/2.8 Version 2. Future posts will deal with 3 Contax G lenses and the very interesting Leica Macro-Elmarit-R 60/2.8.

On Your Bike, NEX-5N & Distagon 18/4

As ever, do click on the pictures for a much clearer view on larger pictures.

So how does it work ?

Using the lens is not without inconveniences, but, in a word : brilliantly. Contrary to my (FABULOUS) Zeiss ZM Biogon 25mm/2.8, this is not a symmetrical lens and should work much better on the NEX-7. The NEX-7’s smaller pixels make it much more adverse to symmetrical designs such as the Biogons and some early Leicas. But no such problem with this lens, in theory (that being said, I have seen some pretty grubby results from non-symmetrical 85mm lenses on the NEX-7 …)

At any rate, on the NEX-5N it is very very nice.

Colour is quite warm, as is often the case with Zeiss, but not unpleasantly so. The weather during our meet-up was appalling. Overcast, drab, flat, cold and wet. You can see on the unprocessed images that colour contrast is very high and tonal separation very impressive in these conditions. A lesser combo would have rendered a muddy grey scene requiring a lot of post-processing with probably harsher results.

As with good Zeiss lenses, the rendition has a 3D pop that no other brand seems able to give you. In spite of its naturally large depth of field (it is only F/4 and a very short focal length), the lens clearly separates planes.

Kiosk and kiosk, NEX-5N & Distagon 18/4

Bokeh, well, if bokeh has a meaning for a lens with that sort of depth of field, seems a bit on the busy side to me, at 100%. But in real-life shots, you’ll never notice.

A taste of ZM Distagon Bokeh

If you look at the enlarged version of the full frame, you will also notice a total absence of purple fringing, which is quite remarkable in that terrible light. This is still true at 100% on ALL my full size pictures of that day!

You will also see that there are absolutely no issues with colour casts on the NEX-5N.

Is it sharp?

OK, you’ve been patient, but I know what you’re all asking. How sharp is it? Very sharp! Click the picture above for a larger view of the calendar sign (about 15 inches from the camera). For more distant subjects, here’s a series a frames shot at all sorts of apertures. Heres’ the test scene (you can see the Distagon 18/4 only has slight distortion, from the top line):

The Lady and the Bike, NEX-5N & Distagon 18/4

I dislike lab tests, as they show nothing of real-life conditions. But here are 4 enlargements of the very bottom right corner. A dark subject in dark corner under very dull light. If you need something worse, you need your head readjusted 😉 Also note that these are not indicative of the quality of the lens, only how well it works on the NEX-5N in real situations. So, in the first shot, the corner might actually be out of focus (focus was on the red tube further left, easier to use), see below for comments. But that’s what you’d get in real life. (did I mention real life ? ;))

@f/4

@ f/5.6

@ f/8

@ f/11

So, yes, the outermost pixels are a bit sharper when you close to F/8, but it would take a largish print to even notice. The fact is that the lens made a visually nice picture of what was a very drab scene. And that’s more important. So, I doubt that you could find a much sharper lens out there for this camera. Judging from the MTF curves of both this, the Elmarit-R 19/2.9 (version 2) and the Leica Super-Elmar-M 18/3.8, there’s simply nothing in it. In the center ? There’s simply no need to worry about aperture … It’s sharp alright.

So what’s not to like?

If you’re getting the impression that lens appealed to me, you’re correct 🙂 But there are a few caveats I’d like to point out.

First, build is very good but the focusing ring was not tight enough for my liking. That’s a matter of personal taste, but the focusing on my Elmarit 19 v2 or the Biogon 25 are much tighter and more pleasant. To each his own.

Secondly, although way smaller than the Elmarit-R 19, it isn’t that small for a slow lens. At f/4, you could hope for something tiny, even for a wide angle, and the ZM Distagon 18/4 simply isn’t. It not large or obstrusive by any measure of the imagination, but when you’ve held a Summicron-M 28 (40mm x 53mm) or even my Biogon 25/2.8 (40mm x 52mm), it does feel very slightly cumbersome (46mm x 65mm diam). Note that the Leica isn’t any smaller and requires a 77mm filter ring!

More important is the paradoxal difficulty in focusing with the NEX-5N. Depth of field being so big, the focus peaking feature is not very helpful as the whole frame tends to be sharp even when magnified and I have found myself back focusing once or twice (and only slightly, it would matter only for critical focus needs). Oh the irony 😉 This shows on the picture below where I was trying to get the handkerchief in focus. A lower setting of focus peaking would probably help, but that would be a pain for street shooting. It would work for landscapes on a tripod, though.

The Abandonned Hankie, NEX-5N & Distagon 18/4 @f/4

All in all, an excellent lens, that I strongly recommend if the limitations expressed here do not bother you. For the price, you are getting one very very good lens with absolutely no technical limitations and the true Zeiss look. I would dearly love to compare this with a Leica 18mm f3.8 Super-Elmar-M (if anyone wants to send one over to me or exchange with my Elmarit-R 19 version 2 :))!

Will I get one? I’m not sure. I’m still hoping to get my hands on a full frame mirrorless, one day. For full frame, a 21&28 might make more sense than a 18&25 combination for my style. And that Leica Summicron-M 28 still is the best lens I’ve ever tested in that focal range … Time will tell, I guess 🙂

I leave you with a couple more pictures from the all too brief session. Once again, a very big Thank You to Philippe for sharing this with Caroline and I.

Behind The Kiosk, NEX-5N & ZM Distagon 18/4 (vignetting added manually)

Closer, note the 3D pop

Blue Nose (enlarged from top picture). Sharp enough ? (click & see reflected tree)