The Zeiss Planar was one of the sharpest normal lenses back in the film days. In this review I check how well it performs on the 24MP Sony a7.

Thanks to Uwe for loaning me the lens and Techart adapter for this review!

Sample Images

Sony a7 | Zeiss Planar 2/45 | f/8 | full resolution

 Specifications

• Diameter: 56mm
• Length: 39mm
• Weight: 190g
• Filter Diameter: 46mm
• Number of Aperture Blades: 6
• Elements/Groups: 6/4
• Close Focusing Distance: 50 cm
• Mount: Contax G

More information in Zeiss’ official data sheet.

The Carl Zeiss Planar 2/45 usually sells for around $310-350 at ebay.com (affiliate link). 
In Germany you can buy it for 240-280€ at ebay.de (affiliate link). 

The  rarer black version sells for quite a bit more.

Versions

There is only one version of this lens. It comes in two colors: Titan and black but black is much rarer.

Compatibility

The Zeiss Planar 2/45 was originally developed in the mid 90’s for the Contax G1 and it’s successor the Contax G2. Both are AF rangefinder cameras.

Adapting Contax G lenses to modern digital cameras comes with two challenges. Since the Contax G cameras have a rather short flange focal distance of just 29mm you cannot adapt them to DSLRs. The advantage of this short flange focal distance is that adapters for mirrorless systems are only about 11mm thick. The other problem is that the  lenses do not have a focusing ring, just AF coupling so the adapter must provide some means to focus the lens.

There are two kinds of adapters, purely mechanical and electronic adapters.

Mechanical adapters are available for EOS M, Fuji X, M43 and Sony E-mount. They come with their own focusing ring. They range in price (affiliate link) from $25 to $140. I own a cheap adapter of the $25 class and it totally sucks, the focusing experience is awful. I have heard good things about the Kipon and Metabones adapters but I haven’t used them personally.

The Techart TA-GA3 adapter is very interesting because you can use AF with newer Sony E-mount cameras! AF with the Sony a7, a7r and a7s is unusable (very slow and unreliable) but with the a7II and a7rii it works quite okay most of the time.

The AF experience is certainly not as smooth as with native lenses. The screw driven AF is rather loud and while it tracks small changes in focusing distances well it is quite slow to realize larger changes in focusing distance. Reliability was good enough not but not on the same level as the native lenses. It also fails when it is a bit darker in situations where native lenses still work reasonably well. I found it usable in some scenarios but often enough I changed to manual focusing which is realized with a small wheel at the 2 o’clock position. Manual focusing with this method works better than I would have expected but can be a bit fiddly at long distances.
The Techart TA-GA3 adapter sells for about $250 at ebay.com or amazon.com (affiliate links).

Build Quality

The Zeiss 2/45 feels very nice and solid.

The barrel is made of metal, supposedly titanium.

All markings are engraved.

The Planar is made in Japan.

I did not diasassemble the lens so I can’t tell you how it looks on the inside and how reliable it’s construction is.

Size, Weight and Handling

The Zeiss Planar is very well well balanced on the Sony a7. At just 190g  with a small diameter and the short adapter it is significantly smaller than the FE 1.8/55 or most adapted 50mm lenses.

The Zeiss does not have a focusing ring. How you focus depends on the kind of adapter you use. I used a Techart adapter. To manually focus you turn a small dial which you see to the left of the TECHART branding on the image above. The experience is of course not as nice as with a real focusing ring but it works well enough, I never had the urge to throw adapter and lens into the nearest pond. I had that urge quite often with my cheap manual $25 adapters.

The aperture ring has full stops from f/2 to f/22 which register nicely but it isn’t too easy to select half-stops because the aperture ring doesn’t travels very far.
If you use the Techart adapter it won’t record the actual aperture you used. You can change the aperture in the camera but all this does is that it overexposes your image by as many stops as you have stopped down (e.g. f/5.6 will result in a 3 stops overexposed image).

Lens Hood

The Contax Metal Hood GG-2 has a little larger diameter than the lens and it is about 10mm deep. It provides decent protection for the front of the lens.

Filters

The 46mm filter thread is made from metal.

The front of the lens does not rotate so polarizers are easy to use.

Image Quality

Vignetting

At f/2 vignetting is rather strong at 2 stops, moderate at f/2.8 (1 stop) and from f/4 it is  average to low at 0.7 stops.

Flare Resistance

The flare resistance of the Zeiss 2/45 is good but not perfect. Under extreme conditions you can see some veiling flare which causes contrast loss. In most situation contrast is great.  I never saw any ghosting.

Distortion

The Planar shows a small amount of barrel distortion, a setting of 4 corrects it very well in Lightroom. So distortion is nothing to worry about.

Chromatic Aberrations

I see some lateral CA, not too much but I would correct it.

Bokeh

At f/2 the Zeiss Planar 2/45 has quite busy bokeh with very defined out of focus highlight discs.

Stopped down to f/2.8 bokeh is much smoother but you will clearly see the hexagonal shape of the aperture blades.

So all in all bokeh is not a strength of this lens

Sunstars

The Zeiss Planar 2/45 has only 6 aperture blades so sun stars have only 6 rays and are not well defined.

Sharpness

When used on the Sony a7 series the Planar shows rather strong field curvature so in my test shot corners will look very bad at wider apertures when the Planar is focused on the center but the corners are quite sharp from f/2 when you focus on them.

The full aperture series can be found in my flickr Zeiss Planar 2/45 album.

f/2.0: Good contrast and very good sharpness in the center but the midframe region already suffers and the corners are soft. That’s if you have a flat subject and focus on the center, when you focus on them the corners are sharp from f/2.

f/2.8: Excellent contrast and sharpness in the center, the midframe region is very sharp as well but the edges and corners are out of focus.

f/4: The edges are excellent as well now, corners remain out of focus.

f/5.6: The corners are decent as well now.

f/8: Excellent across the frame, only a little field curvature remains.

f/11: A little less sharp due to diffraction.

So for landscape photography you should take the field curvature into consideration and stop down at least to f/5.6. For other applications with a three dimensional subject at any aperture you can put your focus anywhere in the frame without worrying about sharpness.

Alternatives

Zeiss Loxia Planar 2/50 – The Loxia is a bit bigger and much more expensive but it has a very pleasant focusing ring and  none of the field curvature issues. It shares the very high contrast and not that great bokeh but at least it has 10 aperture blades and makes great sun stars.

Zeiss C/Y Planar 1.4/50 – Quite a bit bigger and not as sharp at wider apertures but more pleasant bokeh and much nicer handling for a lower price make this an attractive lens for those who want a 50mm Zeiss lens.

Voigtlander 1.5/50 – The Voigtlander is a rangefinder design as well, it’s strength is very pleasing bokeh and nice sun stars. The Zeiss will perform a bit better for landscapes.

Zeiss Milvus 1.4/50 – A gigantic lens with a gigantic performance and a hefty price tag from Zeiss.

Minolta MD 2/50 – The Minolta doesn’t have as effective coatings and a bit lower contrast but it is small, affordable and very sharp.

Conclusion

pros Excellent contrast and sharpness (stopped down) Small and light flare resistance build quality

average vignetting lateral CA

cons awkward focusing strong field curvature bokeh price

The Zeiss Planar 2/45 isn’t a lens for shooting portraits. At f/2 it is one of the sharpest ~50mm lenses you will find but but the bokeh is way below average. The focusing issues don’t help much either.

The Planar excels at producing images of landscape and nature. But you should keep  the field curvature in mind and the focusing is certainly less pleasant than with other lenses. But thanks to it’s outstanding contrast and sharpness many of my images taken with this lens stand out to me.

The small size is definitely a plus, there are few other 50mm lenses which are as small.

The price/performance  is not that attractive, you will have to deal with the cumbersome focusing  and the lens excels only at a small range of applications. You should also invest into a good quality adapter which will set you back at least $120 and the only other lens of the Contax G lineup which I can recommend on the a7 series is the Sonnar 2.8/90 which is a pretty great lens but you will use that adapter for two lenses at most.

So all in all it is a special lens with a rather narrow range of applications but it excels at those. If you take the price into consideration this lens will appeal only to those who already own half a dozen other normal lenses because of their different rendering for those users it should have a strong appeal.

The Carl Zeiss Planar 2/45 usually sells for around $310-350 at ebay.com (affiliate link). 
In Germany you can buy it for 240-280€ at ebay.de (affiliate link). 

If this review was helpful to you, please consider using one of my affiliate links. I will earn a small commission on your purchase and it won’t cost you anything. Thanks!

Zeiss Planar 2/45 T* Sample Images

All images are processed in Lightroom from Raw. Many more full resolution samples in my Zeiss Planar 2/45 flickr album.

Other Articles

• Manual lenses on the Sony a7 – a beginner’s guide
• 15 affordable manual lenses for the Sony a7 series
• My other lens reviews