Since the introduction of the Contax Distagon 2.8/21 in the early 1990’s, the 21mm lenses from Zeiss have a long and glorious history of being some of the best wide angle lenses in the world. While the Loxia 2.0/35 and the Loxia 2.0/50 are refined ZM-Designs, the Zeiss Loxia 2.8/21 is the first Loxia lens that features a new optical design. Lets have a look if the Loxia 2.8/21 can keep the heritage alive.
31/05/17 Update by Bastian: I have been using this lens regularly for a year now and Jannik asked me if there is anything I would like to contribute to his review, so I added a few notes and sample images.
- Diameter: 62 mm
- Length: 72/85 mm (without/with caps and hood)
- Filter Diameter: 52 mm
- Weight: 394 g
- Number of Aperture Blades: 10 (straight)
- Minimum focus distance: 25 cm
- Max. Magnification: 1:7.81
- Elements/Groups: 11/9
- Mount: Sony E
More details can be found in Zeiss’ official data sheet.
As good as it gets and similar to the Zeiss Loxia Planar 2/50mm. Except of the lens caps, everything is made from metal and glass. The physical appearance of this lens is very close to the other Loxia lenses as the housing shares the same diameter. Only difference is that the 2.8/21 is a bit longer.
The scratch resistance of the paint has still to be proven. I hope it performs better in this regard than the Sony/Zeiss E-Mount lenses, which collect scratches easily.
Although there is no further information about weather sealing, the lens has a rubber gasket around the lens mount. Therefore, I would still be careful bad weather conditions. While there is still no Sony camera with advanced weather sealing, this is no problem to me.
Different to the Loxia 2/35 and the 2/50, the lens hood has a tulip shape. Even the markings and the Zeiss badge of the lens hood are engraved. The inside of the hood is lined with black felt to prevent reflected light. The bayonet mount doesn’t hold the lens hood very tight.
As with every Zeiss lens family, the lenses of the Loxia line are designed to have many aspects in common.
The focus and aperture rings have to be operated manually. All lenses of this line use an electronic connection to communicate EXIF-data and to activate the focus magnification while turning the focus ring .
The position of the aperture ring and the focusing ring is exactely like the Loxia 2/50 which I like. Some claim, that the aperture ring isn’t different enough from the focus ring. In my own use, I dont’t have a problem with that. Just move the fingers backwards until they hit the front plate of the camera. Then turn the ring, it can only be the aperture ring. The aperture ring is declickable for video use and has 1/3 stops. This is a bit annoying to photographers, because the rotation of the ring takes too much time if you want to move from f/2.8 to f/11.
The focus ring turns 90°. The focus throw from from 2m until infinity is around 7mm which is a bit too short. Critical focusing can be a little tricky with this lens. It can focus slightly past infinity.
There are almost no non moving parts to grab to mount or unmount the lens, if this is something that may bother you have a look at the Loxia Lens-Grip from PocketPano.
I really like, that Zeiss could manage to use the 52mm filter thread of the other Loxia lenses.
One thing, that I find amazing, is that even the resistance and dampening of the focus and the aperture ring is the same with the Loxia 2/50 and the Loxia 2.8/21.
The Zeiss Loxia 2/50 and the 2/35 show a focus shift. This can be annoying, therefore I was curious if the Loxia 2.8/21 shows the same behavior:
This is a 100%-Crop from the center. I didnt move the focus ring between the two pictures. Gladfully, there is no focus shift with the Loxia 2.8/21mm. I did this test at close distance too and got the same result:
The Loxia 2.8/21 shows some slight barrel Distortion with a strong mustache-style sub-frequency. This is not easy to correct without a profile.
The original examination was, that Vignetting gets slightly better until f/5.6 but worse at f/8. This is physically not logical but I repeated this test a few times and confirmed that result.
Therefore, I did a new test with the Loxia 2.8/21. First, I did an aperture series with the lens mounted correctly, so that it had electronic contact to the camera and submitted the aperture value and everything else(left side). Then, I slightly turned the lens until it didn’t have any contact to the camera. The results are displayed at the right side.
It is very interisting to see, that vignetting is already corrected in the RAW files until f/4. In reality (right side), vignetting at f/2.8 is much worse and is only marginally corrected in RAW from f/5.6 on.
The real vignetting at f/2.8 is around 2.5 EV.
Although it is no APO-lens, chromatic aberrations are on a very low level. I didn’t notice any significant longitudinal chromatic aberrations. Lateral chromatic aberrations are on a very low level too. The highest level of lateral chromatic aberrations that I noticed can be seen in the following image:
Flare & Glare
I didn’t find any glare with the Zeiss Loxia 2.8/21, the T*-Coatings do a great job here.
The lens can produce two different types of flare:
The first one can appear at the edges of the image when the lens hood is not used. I recommend to use it in critical situations.
The second type consists of a few small segments and a pitch circle.
Here you can see the pitch circle, it is not very pronounced:
Here are the small artifacts:
These samples show the worst situation I could archieve with the Zeiss Loxia 2.8/21. I pointed the camera straight into the sun and moved until I found the flares. In most situations, flares are not an issue with this lens.
Comment from Phillip: The Loxia 2.8/21 shows a remarkable flare resistance, I don’t know another lens which comes close here. The Sony FE 4/16-35 is clearly inferior in this aspect as is the Milvus 2.8/21 I could try a couple of weeks ago.
Comment from Bastian: I like to have the sun inside the frame as part of the composition and the Loxia 21mm 2.8 has proven to be an exceptional performer in this regard, rarely showing any ghosts at all, even under very demanding conditions:
Bokeh is not a major concern with SWA lenses because you rarely have shallow depth of field. You have to get very close to the subject to get some blur without stopping down but even then the Zeiss Loxia 2.8/21 performs surprisingly well for a SWA lens.
For the test I chose a critical subject close to the minimal focusing distance.
f/2.8: The background blur looks surprisingly decent. The bokeh balls are nearly round although you can see the shape of the aperture very slightly. The reason for this is that the aperture is already slightly closed at the f/2.8 setting. The borders of the bokeh balls can show some bokeh fringing, but that is not really strong. The foreground bokeh can be a little nervous wide open. You can see this on the brigh brown vertical branch in front of the focus plane.
f/5.6: At this aperture, the shape of the aperture is clearly visible, resulting in 10-edged bokeh balls. The foreground bokeh is a bit smoother.
Comment from Bastian: Highly corrected modern wide angle lenses, especially those using aspherical elements, often struggle when it comes to bokeh rendering, showing harsh transitions, structures in the light discs and severe outlining. But I think the Loxia’s bokeh isn’t too bad actually, light discs are pretty evenly lit and show even less outlining compared to the Zeiss Batis 18mm 2.8. There is one thing to be aware of though: the aperture blades are slightly closed already at f/2.8. On the one hand this is the reason you will already see sunstars around point light sources wide open (which I like) but on the other hand light discs are not perfectly round even at f/2.8:
The Zeiss Loxia 2.8/21 shows sun stars already wide open. A close look inside the lens shows, that the aperture seems to be slightly closed at f/2.8. I dont’t know the reason for that, maybe the lens could be brighter than it is. The sun stars with 10 rays are absolutely beautiful, I really like them.
Comment from Bastian: So do I 🙂 You can find more sample images with sunstars in my flickr album for this lens.
The lens is sharp across the frame wide open. The center of the Zeiss Loxia 2.8/21 shows peak sharpness at f/2.8. The midframe peaks at f/4 and the corners slightly increase until f/5.6 although the differences need to be searched with a magnifying glass. Diffraction becomes visible at f/8 and obvious at f/11.
Comment from Bastian: On the 42mp A7rII the Loxia 21mm 2.8 is still an exceptional performer regarding resolution, contrast and clarity.
The Loxia 2.8/21 does not feature floating elements. I expected the lens to be somewhat soft near the minimum focus distance. Surprisingly, the difference between f/2.8 and f/5.6 is not that high. The Loxia 2.8/21 performs excellent at every distance.
Update by David
Actually although it’s not mentioned in the specifications in words, the Zeiss catalogue shows this lens and the 25 both having floating elements. I checked with the distributors and they confirmed this. That explains the excellent close performance!
The Loxia 2.8/21 shows some visible coma and astigmatism wide open in the corners. It is reduced at f/4 and mostly gone at f/5.6. If the corners are not perfectly in focus, stars can become stripes due to astigmatism. Coma is significantly less visible with darker light sources.
Most of the image is completely coma-free, just the outer region is affected. The picture below shows the charasteric of coma in the top right of an image.
Use for Astrophotography
Comment from Bastian: Meanwhile I got the chance to use this lens for astrophotography under very good conditions and it is a great performer. Stars are less demanding than city lights and it is very hard finding deteoriated stars at all wide open, so I wouldn’t hesitate using it at this aperture. See this 100% crop from the extreme corner for reference:
The only bummer is the high vignetting wide open, but the competition (e.g. the Zeiss Batis 18mm 2.8) isn’t exactly better here.
Zeiss Loxia and Fotodiox Tough E-Mount
I have started this review using a Sony A7R with Tough E-Mount LT Signature Edition to prevent any influences caused by the original bayonet.
Unfortunately, the flange distance of my Tough E-Mount LT is slightly higher than with my original plastic/metal bayonet. Focusing on infinity is not possible with my Tough E-Mount LT!
One more problem with the Tough E-Mount LT is the rubber gasket. It slightly overlaps the original bayonet so that it doesn’t hit the metal ring. The Tough E-Mount LT was constructed wider than the original bayonet to prevent light leak. When mounting a Loxia lens, you have to press the lens pretty hard, so that the rubber gasket is squeezed to the sides. Although I can not imagine, that it is bad for the lens itself, this could possibly damage the rubber gasket in long term use.
While the Tough E-Mount LT works great with my native lenses, you should be aware that the use of the Loxia 21mm f/2.8 with it could not work in your case too.
First of all, this lens is very sharp from f/2.8 on. This is a great archievement, especially if you take the small size into account. Even more remarkable is, that this lens is sharp from close-up until infinity without using floating elements.
Vignetting and Distortion are visible, but not extreme and easily fixable with a lens profile. The lens performs very well against bright light and has no problems with veiling flare. Ghostings are small and often unobstrusive if there are any of them. Just take care if the sun is placed in the golden ratio where the lens shows the strongest ghosting.
In terms of character, the Loxia 2.8/21 really rocks. This lens shows awesome high contrast even wide open and renders colors beautifully. The clarity of the images is very high. The bokeh is very nice for a 21mm lens, especially in the center. The sun stars are amazing. They contribute in a great way to the character of the lens.
The build quality and the handling are top-notch although the exact focusing can be a little tricky. The possibility to take 52mm filters and the small size are outstanding. The high price tag reflects itself in terms of build quality, although I miss a lens bag in the box.
I think that the Loxia 21mm f/2.8 is one of the best wide angle full-frame lenses of the world. If you are looking for a very high performance, fast and very compact wide angle prime, the Loxia 2.8/21 is one of the best choices for your Sony FE-Mount Camera.
Comment from Bastian: I tend to agree and think this lens might be the best one for actually taking photos that Zeiss has ever built. Whilst I welcome the optical performance of the Otus lenses what I really want to use are well balanced lenses with exceptional performance in a small package. The Loxia 21mm 2.8 is exactly this, and the Loxia 85mm 2.4, that has been released in the meantime, offers a very similar performance at a different focal length. I hope further Loxia lenses will continue this trend.
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The full size sample images are only edited in terms of contrast. No sharpening or noise reduction added.
Comment from Bastian: You can see some more sample images in my flickr album for this lens.
Full Size samples added on 01.03.2016 with the proper lens:
More sample images taken with the defective lenses to show the rendering, no full size samples of these.
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