Sony A7 Loxia 35mm and Sony a5000 Sonnar 35mm featured 2

The Street Shooters – Zeiss Loxia 35mm f/2.0 vs. Zeiss Sonnar 35mm f/2.8

We don’t always do gear tests at iLHP but when we do, we go all out. This lens shootout will feature a Blackbird spy plane, two beautiful models on Melrose Ave., and the Space Shuttle Endeavour.

Space Shuttle Endeavor
Come on. Who else gives you a space shuttle in a lens review??

The 35mm is an ideal focal length for street photographers. Wide enough to capture subject within close proximity, not so wide that distortion becomes an issue or too many distractions are in the frame. Leica has long had their famous range of 35mm Summiluxes and Summicrons for street photogs. However, the 35mm is also a secret weapon for fashion/portrait photographers like Terry Richardson or Annie Leibovitz.

This comparo will be broken into 5 rounds:

  1. Build quality
  2. Sharpness
  3. Vignetting and Flare
  4. Bokeh and 3D Pop
  5. Real World Handling

The Contenders & Their Specs

Zeiss Sonnar 35mm Loxia 35mm Sonnar 55mm
All of these lenses are made from metal. Though similar in size, the Loxia feels much heavier than the Sonnar 35mm. Zeiss Sonnar 35mm f/2.8 (left); Zeiss Loxia 35mm f/2 Biogon (center); Zeiss Sonnar 55mm f/1.8 (right).

On the left, weighing in at a featherweight 120g with a $798 price tag, is the Zeiss Sonnar T* 35mm f/2.8. In the middle, weighing in at a hefty 340g with a $1,299 price tag, is the brand new Zeiss Loxia T* 35mm f/2 Biogon. And for reference, we have the spectacular Zeiss Sonnar T* 55mm f/1.8 on the right.

At almost 3 times the weight of the Sonnar, the Loxia is beefy for such a small lens. In fact, it is heavier than the larger Sonnar 55mm f/1.8 (281g). This is undoubtedly due to more glass, since the Loxia has 9 elements whereas the Sonnar has 7.

The key distinction here is that the Loxia is a manual focus lens based on the classic Zeiss Biogon 35mm f/2 rangefinder lens built for Leica. It is also a smart manual focus lens, in that it fully communicates with the A7, allowing for accurate aperture and exposure information. Importantly, it enables the camera’s Focus Magnification feature automatically via a twist of the focus ring (check out the video above). This is a wonderful feature.

Round 1: Build Quality (Loxia Wins)

Sony A7 Sonnar 35mm and Loxia 35mm
Metal lenses have a higher perceived quality by the consumer but they also dent or chip more easily than plastic lenses. Often, they are also heavier for the same sized lens.

Both the Loxia and the Sonnar are constructed entirely of metal, which seems to be the defining feature of a high quality lens nowadays (there is nothing wrong with plastic, just look at the Canon L lenses). While the Sonnar is very good, the Loxia is superb. The manual aperture ring has 1/3rd stop clicks and each one “snicks” into gear like the fabled Honda S2000 6-speed manual transmission. The Loxia honestly feels better than some modern Leica lenses.

Loxia 35mm weather sealing gasket
The Loxia features a thick blue rubber gasket at the mount which inspires confidence when shooting in damp conditions. Neither of the other Sonnars are sealed in such a way.

The Loxia is also weather resistant. It features an attractive and functional blue gasket at the rear of the lens where it meets the mount. The entire lens is metal of course, even down to the lens hood. This is a double-edged feature. While the velvet lined metal lens hood reminds you of old Leica lens caps, metal hoods are also prone to dings and being bent in a crowded camera bag. It reminds me of my old Pentax lenses with retractable metal hoods, none of which are in pristine condition anymore.

The curious case of the infinity focus (see below).

I experienced one curious issue with the Loxia’s infinity focus. The infinity stop was inaccurate. It means, if you dial the focus ring all the way to infinity, it didn’t actually focus to infinity. You have to dial it slightly back towards 5m (as shown above) to actually have everything in focus. I’m chalking this to the lens being an early production copy. Hopefully, future Loxias won’t have this issue.

[March 19th, 2015 Update] As some of our astute readers pointed out, my curious issue with the infinity focus on the Loxia 35mm may have something to do with the lens design. Yesterday, we received new information direct from Zeiss USA and let me share it here.

On the Loxia 35mm, the infinity focus is adjusted slightly before the stop and the ∞ marking. This is on purpose. The common reasoning behind this would be to account for temperature variations. However, for the Loxia 35mm, the reason behind this is more subtle. The Product Manager of the Loxia line pointed out to us that the effects of temperature variances typically affected longer focal lengths. In the case of the Loxia 35mm, the tolerances have to do with the global systems lens on the Sony camera mount (no doubt because the Loxia is based on the original Zeiss 35mm f/2 Biogon). He said that:

“Because of these potential variations, and to ensure that it is always possible to focus on infinity, we adjust the infinity focus slightly before the stop.”

Round 2: Sharpness (Sonnar Wins)

California Science Center
This will be our test shot, the world’s only Lockheed A-12 Blackbird Twin Seater Trainer, displayed in front of the Californian Science Center on an uncharacteristically cloudy Los Angeles day.

To be honest, this was a bit of a surprise. I’d expect a niche $1,300 modern manual focus prime to trounce a $800 mainstream autofocus lens. I wanted the Loxia to win. It felt sharper when I was shooting it. But it wasn’t the case.

Procedurally, all test shots were taken with a Sony A7 on a tripod+remote with the lens focused to infinity. Lenses were rented from so the sample size is “one.” Camera was set to shoot RAW with all autocorrections turned off. Images were processed via Lightroom without corrections or sharpening.

Click on the image for full resolution. Pay attention to three things: (1) the US Air Force text (2) the rivets on the jet; and (3) the dark green tree behind the jet. Disregard the lighter green tree to the right. The sun was shining through the clouds and hit that particular tree, which may skew the results.

The Sonnar 35mm’s center performance is brilliant wide open at f/2.8. This pretty much confirms other lab tests from Photozone and DPReview. It easily out resolves the 24.3MP Sony A7, no doubt happily satisfying the 36.4MP Sony A7R resolution beast. I didn’t expect the Loxia to outperform the Sonnar wide open but the results at f/2.8 surprised me.

Loxia-Wide-Open iLHP
Center @ 100%. There may be some messed up infinity focus here on the jet due to the faulty infinity stop, but regardless, the dark green tree and buildings in the background are not as sharp as the Sonnar.

Wide open, the Loxia is softer than the Sonnar. We are pixel peeping here, and I suspect for most street and portrait photography, the difference is negligible. Landscape photographers will moan but what kind of landscape photographer shoots wide open anyways? If you pay attention to the “U.S. Air Force” text, the rivets on the jet, and the dark green tree in the center, it is quite muddy.

Center @ 100%. The Sonnar wide open is much sharper than the Loxia wide open.

Comparing the Sonnar to the Loxia wide open, the difference is remarkable. The individual rivets are clean. The text has sharp edges. The tree has a ton of detail. Just what are you getting for paying the extra $500 with the Loxia? Build quality? Panache?

Loxia-f2.8 iLHP
Center @ 100%. Even when stopped down to f/2.8, the Loxia’s center sharpness doesn’t approach the Sonnar.

If we stop down the Loxia to f/2.8, the image quality improves quite a bit, but not to the level of the Sonnar. While it is much sharper than wide open, the rivets and text are still not as clean and there is less detail in the tree. The Loxia’s center performance never rises to the level of the Sonnar even when stopped down further. This is certainly a bit disappointing for an expensive manual lens.

Disregard the different color casts between the two lenses here, because it was partly cloudy day and the sun was shining through the clouds for the Loxia shots. Click on the image for full resolution.

Corner sharpness follows the same trend. The Loxia is quite soft in the corners at f/2. The Sonnar is also soft wide open, but less so than the Loxia at f/2. Comparing both lenses at f/2.8, the Sonnar is still sharper. In fact, the extreme corner (the most lower right bush) never sharpens up on the Loxia even if you stop down. This could be due to the Biogon design, as discussed in an earlier article, and the angle the light is hitting the mirrorless sensor.

Round 3: Vignetting and Flare (Loxia Wins)

Space Shuttle Endeavor Ceramic Tiles
The belly of the Endeavor, showcasing the thermal protection system made out of multiple types of ceramic tiles depending on heat stress during orbital reentry.

I went inside the Californian Science Center soon after I took the Blackbird test shots because it suddenly started pouring. I was greeted by the magnificent Space Shuttle Endeavor. It was a humbling sight.

I thought we’d try something that’s never done before in a camera lens test. Instead of shooting a blank drywall or a brick wall to test vignetting, we’d shoot the ceramic tiles lining the underbelly of the Space Shuttle. iLHP readers and subscribers only get the best. :)

Zeiss Sonnar-and-Loxia-35mm-Vignetting
Adjusted to grayscale.

The Loxia outperforms the Sonnar in terms of vignetting. The Sonnar’s corners doesn’t brighten up until f/5.6-8. The Loxia shows less vignetting from f/4 onwards. Remember, while you can correct for vignetting in Lightroom, bringing up dark corners introduces noise also, so it is better taken care of optically.

Space Shuttle Endeavor front maneuvering thrusters
The front maneuvering thrusters of the Space Shuttle. Badass! Taken by the Loxia 35mm @ f/4.

Flaring or ghosting was not an issue on either lenses, unlike my experience with a 1956 non-digitally-optimized Leica Summaron 35mm f/2.8. That being said, the way the lenses handled flaring was different. The above shot of the Shuttle nose featured dramatic sunstars from the overhead halogen lamps and a blue-green flare.

Space Shuttle Endeavor Rear Thrusters flare
The rear main thrusters. Notice the ceramic tiles wrap all the way around the flaps. Very cool. Shot by the Sonnar 35mm @ f/4.

The Sonnar also showed a blue-green flare but I could not reproduce the sunstar indoors at the same aperture. Note, the Sonnar has 7 circular aperture blades and while the Loxia’s number of aperture blades are unspecified by the manufacturer (weird). I counted 10 curved aperture blades like the original Zeiss Biogon 35mm f/2. I’ll let you decide which type of flaring you prefer.

Round 4: Bokeh and 3D Pop (Loxia Wins by a Complete Landslide)

Loxia 35mm shot at f/3.2! At this focal length and aperture, a lens is not supposed to produce this much dimension in the photo. The aperture isn’t even open wide but what is producing the 3D-ness and the pop? Probably Zeiss wizardry.

By now, I was ready to write off the Loxia as a disappointment and move on to the final section, especially since 35mm lenses are not particularly known for their bokeh. But then I noticed something unexpected.

Closer crop of the above image.

This Biogon design Loxia 35mm has fantastic 3D pop and bokeh. Notice the razor clear separation between this model’s long hairline and the background. It is subtle, but to the trained eye, this is unordinary for a 35mm lens at f/3.2. The busy neon sign and menu in the background is blurred ever so pleasingly, so much so that the subject figuratively pops out from the faded background.

The Loxia 35mm has extremely pleasing bokeh.

It seems, the pièce de résistance to the Loxia is its fantastic out of focus rendering. I’ve shot big aperture Canon primes and their bokeh generally don’t come close to this Zeiss (yes, they are more blurry because of the lower depth-of-field (DOF), but they are less pleasing at this particular DOF). Maybe it has also something to do with the Loxia’s flat plane of focus.

Sonnar 35mm @ f/2.8

By contrast, the Sonnar has noticeably less pop even at f/2.8. While it is still very respectable and pleasing, its bokeh is nothing to write home about. Par for a good 35mm lens but not as good as the Loxia.


The separation between her hair and the background is not as crisp as the Loxia. This is what most lenses look like at this aperture, a pretty common scenario for Canon glass. Not bad by any means, but not good either.


Finally, the bokeh, while still pleasing, has harder edges on each point of light as compared to the Loxia. This results in harsher transitions between one blurred elements to another for this Sonnar, where the blurred elements from the Loxia seem to blend into one another more smoothly.

I realize bokeh and 3D pop are harder to quantize than sharpness or vignetting, so I’ll let you be the judge here as well. However, to me, the difference is quite dramatic. I am pleasantly surprised by the Loxia. It seems the $500 premium is justifiable.

Round 5: Real World Handling (Sonnar Wins)

For a faster paced fashion shoot on Melrose Ave, I kept coming back to the Sonnar 35mm. I can trust it not to interfere with my flow. I didn’t have to worry about fiddling with the focus.

This final test was always going to be an uphill battle for the Loxia. Pitting a manual focus lens to a speedy AF lens is almost unfair. No matter how fast you can manual focus, ultrasonic or linear motor autofocus will be faster than your eyes, reaction time, and finger muscles. No Leica fanboys, you are not faster than a USM lens.

Loxia 35mm

Despite the disadvantages of being a manual focus lens, it handled very capably on the streets. With auto Focus Magnification, it was much easier to wield than a traditional manual focus lens. The aperture ring and focus ring were a joy to use, and the lens itself took outstanding portraits.

Sonnar 35mm

But at the end of the day, when I had two models waiting for me under the hot sun and a makeup artist ready to do touch ups, I relied on the Sonnar to save time and hassle. The Sonnar focused quickly and reliably. It is a modern AF lens through and through. It was light (1/3rd of the weight of the Loxia) and nimble. It paired with the Sony A7 body very well. The Sonnar is the workhorse, whereas the Loxia is for the connoisseur.

Final Verdict: Loxia Wins 3-2

This was a closer lens comparison than I thought. The Sonnar 35mm f/2.8 is an excellent lens. Very sharp in the center wide open. Fast and accurate autofocus. It is well worth its price tag. To recap:

  1. Build quality (Loxia wins)
  2. Sharpness (Sonnar wins)
  3. Vignetting and Flare (Loxia wins)
  4. Bokeh and 3D Pop (Loxia wins handedly)
  5. Real World Handling (Sonnar wins)

By the time I finished making the test charts, I thought the Loxia was a dud. Combined with the fact that the lens I received had an inaccurate infinity focus stop, it was disappointing. But the new Loxia fought back in a big way with its trademark Zeiss 3D-pop and character.

Character. That’s really what sums up the Zeiss Loxia 35mm f/2. It is not a perfect len. It is very expensive. It certainly won’t be for everybody, especially pixel peepers. But a huge kudos to Zeiss for taking the risk and designing a lens that was so fun to use and with so much soul.

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