#85. A Contax-G trilogy on the Sony NEX-5N

By pascaljappy | News

Jan 28

Update: the Planar G 45mm f/2 has now been tested on the Sony NEX-7. A summary of all this website’s reviews of the Sony NEX-5n and NEX-7 is now available.

After presenting the Zeiss ZM Distagon 18/4 in my previous post, here are three more lenses from the private collection of Philippe, a fellow photographer who kindly offered to lend me some of his equipment after reading my review of the Sony NEX-5N with Leica-M, Leica-R, Zeiss ZM and Zeiss C/Y lenses.

The Théatre Ephémère in Palais Royal, Pais. Sony NEX-5N & Contax G Planar 45mm/2

Théatre Ephémère, Paris. NEX-5N & Planar 45/2

Today, we are looking at 3 lenses from the lesser known but oh-so-good, Contax G stable: the 28mm f/2.8 Biogon, the 45mm f/2 Planar and the 90mm f/2.8 Sonnar. My time with these lenses was very limited and tet conditions pretty abysmal with terribly flat and muddy light, drizzle and freezing temperatures.

What did I think of these lenses? After looking closely at the pictures at 100% in LightRoom, let’s just say the 45mm and the 90mm are probably the sharpest lenses I’ve ever used, period!!! But if it’s a bed of roses, it’s a bed of thorny ones! Read-on 😉

A tricky adapter

The Contax G system was a wonderful rangefinder system that used to make me dream in my 20’s. There was no way I could afford it, not any more than Leica’s M rival of the time. The G was more ‘advanced’ in that is offered autofocus. While this was great at the time (if you really need autofocus), it’s a major pain in the … today as the lenses do not … focus. Therefore the adaptor has to do the work of sliding the lens in and out, closer or further from the NEX’s sensor, without losing alignment.

NEX to Contax G adapter

From my limited time with it, I can report two things:

  1. Tt works very well. There’s no hint of left/right sharpness asymmetry anywhere in the pictures.
  2. It is a pain. As Philippe put it, “There are two categories of users: those who put up with it because of the quality of the lenses, and the others

Me, I’m with the others 😉 The adapter is wide enough to grab well, and you need it because it is really hard to turn. I’f you’re in love of your 40 year old Leica Elmar because of it’s buttery smooth yet perfectly damped focusing ring, you’re in for boils on your fingers with this one. OK, so I’m exaggerating, but the very high bracket of the adaptor makes it very very firm indeed. There may be others on the market. Check Leitax ?

This being said, it’s no worse than using a view camera or hand holding a Hassie for macro work (right, Philippe 😉 ?) and if you have the time to master this beastie, the lenses are really worth the small effort. On to the lenses!

Contax G 28mm f/2.8 Biogon

This is the worse lens of the three. It’s only very good. As in way better than anything Sony has to offer in E-mount for the NEX-5N (maybe the 24/1.8?). It sharp from edge to edge and shows very little vignetting even wide open. Look at the bottom of the picture below to see that distortion is also minimal.

The Kiske des Noctambles in Palais Royal, Paris. Sony NEX-5N & Contax G 28/2.8 Biogon

The Kiosk again, NEX-5N & G 28/2.8 Biogon

There’s not a lot more I can say about this lens, which I used for only a few minutes. It’s a worthwhile addition to a G collection but I wouldn’t jump the gun for it. It’s no better than my wonderful Zeiss ZM Biogon 25/2.8, I don’t like the very warm tone it gives and the focusing is a pain.

Let me leave you with this … fuzzy picture. It wasn’t done on purpose, but I guess it shows what bokeh can be like if you focus on a subject close up:)

A fuzzy picture, Sony NEX-5N & Contax G 28mm f/2.8 Biogon

Bokeh Bokeh Everywhere, NEX-5N & G Biogonn 28/2.8

Verdict : It’s cheap-ish, small and plenty sharp. But for similar money, I’ll get a Voigtlander used 28/1.9 instead, or a Voigtlander Ultron 28/2.0. It’s nowhere near as good technically but a joy to use and renders so beautifully.

Contax G 45mm f/2 Planar

This is a fantastic lens. If I hadn’t already committed to a system, this one would really sway me. It .. is .. so sharp, at all apertures! It focuses way closer than a Leica M lens. It’s small and sexy. Bokeh is quite nice, in spite of only 6 blades in the diaphragm.

Rainwater on a Paris bench. Sony NEX-5N & Contax G 45mm f/2 Planar

Puddle on a Bench, NEX-5N & G 45/2 Planar

Click the picture below for a real impression of the sharpness and clarity this lens can deliver. Remember the light was terrible. The colour separation here is really stunning. Sharpness and micro-contrast second to none. The small wire netting around the top statues is rendered perfectly. There is absolutely no purple fringing, either. A perfect 10 like I’ve rarely seen before!

Colourful glass bead on the Kiosk, Sony NEX-5N & Contax G 45mm f/2 Planar

Jewels in the Kiosk, NEX-5N & G 45/2 Planar @100%

This one, on the other hand shows the only thing I do not like about this lens: the overly warm cast. It’s a bit too yellow to my tastes, but that’s easily corrected in post processing and easily automated. At least colours are not muted (the reading man was in the shadow on a very overcast day). ISO 200 1/20 F/2.8 (the picture is blurred as I was trembling in the cold, and back focused. Shame on me ;)).

Newspaper vendor, Sony NEX-5N & Contax G 45mm f/2 Planar

Newspaper vendor, NEX-5N & G 45/2 Planar

Verdict: This lens is so much better than my Summicron-R 50 it hurts. If it was a focal range I used more, I would seriously consider getting one. But I don’t (all my lenses – that get used – are either below 35 or above 90, strange isn’t it ..) and won’t. With a full frame sensor, well …

Contax G 90mm f/2.8 Sonnar

This is another sharpness monster. Read any review you can find on the Leica Elmarit-M 90/2.8, look at the MTF curves for that lens at f/8 and you will see it is a damn sharp lens. The Sonnar is sharper. Easily!

Hotel Du Louvre, Paris. Sony Nex-5n & Contax G 90mm f/2.8 Sonnar

Hotel du Louvre, NEX-5N & G 90/2.8 Sonnar @2.8

I do apologise for the lousy quality of the pictures on this page. I had on hour to test 5 lenses and a limited range of subjects. And it was cold. Cold weather annihilates my artistic sense, it seems 😉

Still, look at the colours in this picture of Hotel du Louvre. Vibrant an clean, if – again – a bit too yellow. Micro contrast is incredible. Sharpness is perfect all over the frame. If this level of quality can be maintained on a full frame with no AA filter, this lens can probably deliver the goods over 40Mpix (that’s 40″ prints @200dpi without upresing!) Medium format beware …

Of all these three lenses, this is the only one to display purple fringing (very moderate).

Purple fringing with the Contax G 90mm f/2.8 Sonnar

Purple Rooftops @f/2.8 G 90/2.8 Sonnar

Compare these two pictures of the same building. The first is taken using the Contax G 90/2.8 Sonnar, the second with the Leica Elmarit-M 90/2.8. Notice the difference in colour. To me the Leica is much more natural and realistic (look at the white shutters at middle top). What do you think ?

A posh building in central Paris

"How the Other Half Live" Contax G 90/2.8 Sonnar

Elegant bulding in Paris by the louvre. NEX-5N & Leica Elmarit-M 90/2.8

"How The Other Half Live", Elmarit-M 90/2.8

On the positive side, look at the aerial at top right. The squares are top right are made of wires a few millimeters thick and the aerial is over 100 meters away. Yet, they are resolved individually against a white background. At 2.8. Enough said?

Here’s a battle of the giants at their best aperture of f/8. First the Contax, second the Leica.What my eyes tell me is that the Contax is way sharper than the Leica, if you pixel peep.


Contax G 90mm f/2.8 @f/8


Leica Elmarit-M 90/2.8 @f/8

Verdict: Sharper than probably any other lens of this focal length. A tad clinical and yellowish, I still prefer my wonderful Elmarit, but if you want the sharpest, GO FOR IT !!

General Verdict

All of these lenses work perfectly well on the Sony NEX-5N. Together they offer you a range of astounding technical quality. The adapter is a bit of a nuisance at first, but for slow, deliberate shooting, really not a problem at all. Get all three with a NEX-5N and you will probably be making 24″ prints that will stun you again and again, for the price of a single (cheap) Leica-M lens. Combined with an autofocus lens for everyday family shots, you’d be doing very well. If this tempts you, hurry though. Mirrorless cameras such as the NEX have raised interest in these lenses and prices have almost doubled in a year.

A last word: thank you Philippe !

  • Anker Høyer says:

    I use Metabones adapters for Contax-G to NEX, and they work worderfull smooth ( not buttery like Ziess og Leica, but smooth ), and I never have problems with the focusing ring. Metabones fit the 28mm, 35, 45mm and 90mm.
    I have also used some of the “Kipon-adapter-types”, but they have all problematik/sticky focusing rings, and i can not recommand other than Metabones.
    Contax-45mm i my super-favorit :o)


    • pascaljappy says:

      Hi Anker,

      thanks for pointing this out. These are superb and small lenses with the only inconvenient being the adapter I used. If the Metabones adapter is better, they become a very tempting proposition. I agree with you: even in my short test, the 45 was a clear favourite. A fantastic lens and an incredible bargain at around $300 !!

  • Fotoingo says:

    I can agree with everything you said.
    I own the 28, 45 and 90 mm in black and they are my travel anywhere lenses (+ the Sony 16mm f2,8 E-Mount lens). Light !!, sharp !!! and small !!.
    Only the G 35mm f2 isnt really good.
    Btw : The G 28mm works really nice on the Nex 5-n and the 3c but not on the Nex-5 or 3 because of the “older” sensor.
    My Leica lens kit , 24, 35, 90 mm is way bigger and a lot heavier.
    But: the bokeh and the overal usability of the Leica lenses are fantastic. So choosing my lens kit for my Nex 5n depends on what kind of vacation/shooting I go.

    • pascaljappy says:

      Hi, you are lucky to have such choices 😉

      I think the combination of these 3 lenses with an autofocus Sony lens for ‘everyday’ shots is a winning idea.
      Yes, the Leica lenses are much heavier. They are better built and I like the general looks better. But the complete Contax-G kit is 70% cheaper, at least, and even sharper. At that price point, you probably can’t do better.

  • Fotoingo says:

    I forgot : the way smaller minimum focus distance of the G lenses makes them really nice for macro shots too. When using my Leica lenses I use an Leica to Nex mount adapter with a helicoid, so I can focus a lot closer than normal.

    • pascaljappy says:

      Aha !!! I didn’t know you could do that. What adapter are you using ? Thanks.

      • Fotoingo says:

        I use a Hawks Factory Adapter which you can buy on Ebay. Right now it is not available but you can send a message via Ebay and ask him about it.
        The name is : LEICA-M L-M to SONY NEX E-mount MACRO TUBE HELICOID
        The Adapter works very well but the shorter the focal length the shorter the min focus distnace gets.
        That means with a 24mm you can shorten the min focus distance by estimated 50 %, with a 50 mm by 30 % and with a 90mm 15% So it will not give you a 1:1 macro when used with a 90mm but you can get a lot closer with for example a 50mm.
        Hope that helps.

  • Chris Lewis says:

    Thanks for your review of these lenses, much appreciated. I have the 23/2 and 90/2.8 Zeiss for G and my experience mirrors yours. I love these little lenses.

    I wonder if you have any experience of the 21mm Zeiss for G lens?

  • Chris Lewis says:

    sorry for 23mm read 35mm!

  • Kian says:

    superb lenses on the soon to come Nex-7!

    • pascaljappy says:

      I hope so. Tests performed on luminous-landscape.com and stevehuff.com seem to indicate all is well. Initial tests by other bloggers were a lot more worrying, which is why I went for the NEX-5N instead. But the 7 should be a hoot !!

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  • Philippe says:

    Pascal, great work in so little time and under such conditions! I should know, as I was there…:-). Congratulations! And I agree 100% with you assessment. Maybe just one small item to add. Because the Contax G (and also largely the zM 18 referred to in your previous post) are so contrasty, they are very easy to focus on the NEX. Use a less contrasty lens, and that gets progressively less ridiculously easy, as I found out with my very delicate but soft-contrast Leica R 35-70 f:3.5.
    Regarding various points made in the comments. The Metabones adapter has its supporters, but so does Kipon, For example the Kipon supports the Contax G 21 and 35-70, whereas the Metabones does not, IIRC. The Hawks adapter is great for reducing the MFD of M lenses, but trusted members of another forum have reported loss of infinity focus on some lenses.

    • pascaljappy says:

      Hi Philippe, thanks for the comment and *thanks so much* for letting me use the lenses 🙂

      Yes, low contrast makes it difficult to focus. I find the same happens in low light. Even if the image seems bright on screen, it seems that the focus assist is having difficulties.

      Thanks also for the information on the adapters. Caveat emptor ! See you soon,

  • […] I found this review very interesting, used on Nex-5n: #85. A Contax-G trilogy on the Sony NEX-5N | Dear Susan, Reply With […]

  • I do not agree about the Biogon 28mm, I suggest you to use it for more than a few minutes. At the center, mine is even sharper than the Planar 45mm at all apertures (not at the edges). Also remarkables the flare resistance, the wonderful clarity and a special ability to give volume to things. A really great lens, with a special character. My favorite on the Nex-5n.

    • pascaljappy says:

      Hi Alessandro,

      I didn’t mean to imply the 28 is not sharp. All three Contax G lenses I had the chance to use ware very sharp. And amazing for the price. I’m just saying that, in my experience, the 45mm was my definite favourite. And the 28mm the least. But, as you say, all 3 are technically very good and it’s mre a matter or character. Thanks for the comment, it will encourage others to test the 28 as well. Cheers

  • David says:

    Thanks for testing these lenses under such extreme circumstances! I bought a G 90/2.8 from french seller as it happens and have loved using it on my 5N. As of early 2013 there is also a a US-eBay conversion available (about US$330) to convert these lenses to Leica M. I bought a 45/2 and have had it converted and now use it on both a Leica M8 and also my Sony 5N. The conversion gives the lens a standard M bayonet and a focus ring (alas no tab). I will probably get my 90 also converted in this way.

    • pascaljappy says:

      Hi David, those are fantastic lenses. Thanks for telling me about the Leica M converter. I know Philippe, one of the other authors on this blog, uses an adapter but the converter looks like the more elegant way if you do not want to switch between systems. Have fun with your lenses.

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