The 25mm Batis from Zeiss is a new wide angle lens made for Sony' full-frame, mirrorless cameras.
Design & Build Quality
The Batis line follows the popular mirrorless trend of being small and lightweight without sacrificing performance. The 25mm is compact measuring in at only 3.19″ by 3.07″ and weighing only 11.82 oz. When comparing this to something like the Sigma 24mm 1/4 DG Art (Canon EF) which is 3.35″ by 3.55″ and weighs 1.46 lbs, the difference is pretty significant especially if you will be going handheld for long periods.
With a unique design, the Batis models do not offer any physical focus markings but instead provides a non-traditional rubberized focus ring with a small OLED display that can be enabled to display real-time information like focus distance, depth of field range and aperture reading.
On the front, you'll find a metal 67mm thread useful for adding native-sized filters or larger ones using a step-up ring. The lens body is coated in a matte black finish with small Zeiss brandings upon either side. As you'd expect from a lens of this caliber, the 25mm Batis is fully dust and weather-sealed to allow use in all sorts of weather conditions.
Zeiss packed the 25mm Batis with a lot of competitive features for this type of wide-angle prime in this price range. As you'd expect, the 25mm focal length holds true on a traditional 35mm full-frame sensor providing a viewing angle of 82-degrees, but it is effectively a 37.5mm equivalent FOV on an APS-C sized E-mount body like the a6300. With a maximum aperture of f/2, this lens can achieve a shallow depth of field or bring in lots of light for necessary shooting in dim environments.
Zeiss integrated a distagon optical structure with ten glass elements separated into eight groups. Within this design are floating elements which help to reduce aberrations within its wide focusing range. Out of the ten elements, four of them offer a double-sided aspherical design said to help edge-to-edge sharpness, illumination and cut down on distortion.
On each surface of the lens, there are T* anti-reflective coatings helping to minimize reflections, boosting clarity, contrast and color rendition. The OLED display found on the top of the lens can be configured with an “always-on” mode or simply display information when the settings are being changed.
For such a focal length, the 7.9″ minimum focusing distance is excellent opening up a new realm of close-up shots while still maintaining a wide-angle of view. Internally, Zeiss added linear motors which help the Batis 25mm to offer smooth, fast and quiet AF. However, it is important to keep in mind that you are still getting a focus-by-wire structure so manually focusing during video shooting can become more of a burden than a benefit.
Performance & Function
I think its most competitive feature of the Batis 25mm is its compact and lightweight form-factor. The days where your arms/shoulders are aching after hauling a hefty camera rig all day are soon to be gone and packing a little lens when traveling opens up the potential for a lot of smaller baggage options.
While in Boston for the day, I walked around the city with my a7RII and 25mm Batis handheld and carrying this combination never felt like a burden or inconvenience. I can easily support the camera with one hand and hold it to my eye for long periods, waiting for the perfect shot, without my arm getting too tired.
I do not understand the benefit of the rubberized focus ring as I much prefer the feel and function of a traditional contoured focus ring. However, the manual focus ring likely won't be a huge issue for most buyers as they will be purchasing this model for use with AF since it's focus-by-wire design does not encourage an emphasis on manual focusing.
While the small form-factor looks appropriate and appealing on Sony's compact mirrorless offerings (which it was primarily designed for), it does look a bit odd on a larger and bulkier cinema camera like the FS7:
For this sharpness test, I pinned a local newspaper up against a wall in my office and took the same photo with the aperture/shutter speed being the only variable changed. I stuck to the full aperture stops and did not test 1/2 or 1/4 stops within this comparison.
All shots were captured on my Sony a7RII utilizing its the full-frame sensor so results will vary when shooting with a crop sensor camera. A tripod was used to ensure that the orientation/framing remained consistent, and no handheld/motion blur could have any effect on the resulting images.
As you can tell, the center sharpness is pretty impressive throughout the range with the “sweet spot” looking like f/4. The corner sharpness suffers noticeably at f/2, but regains much of its traction stopping down to f/2.8 and becomes tack sharp at f/5.6. You may notice the sharpness becomes weak at f/22 especially in the corners although this is easily explained by the science of lens diffraction.
Overall, I am satisfied with the sharpness offered by the Batis 25mm and wouldn't hesitate to use it wide open in 95% of scenarios. In the other 5% where I need the best image possible, stopping down to f/2.8 or f/4 is easy enough to boost corner sharpness without losing too much light.
While distortion is typically less prominent in prime angle lenses, it is not uncommon to see it present in some of the wider variants.
As you can see from the example above, the original shot suffers from some minor barrel distortion (in addition to vignetting), but these quickly vanished once I applied the Batis 25mm lens profile in Lightroom CC.
This is easy enough to remove in post for photography, but becomes a slightly more complex beast when it comes to video. However, this is not the type of distortion that most will notice except those with an experienced eye, so I do not think it will be too large of an issue.
When it comes to optical performance, this is the category where I'd rate the 25mm Batis the poorest. When shooting in virtually all aperture ranges, this lens shows notable vignetting with the strongest displayed when the aperture is at f/2. Keep in mind, all of my test shots are taken with a Sony A7RII body which offers a full frame sensor so you'll experience significantly less vignetting on a crop sensor like those used in an a6300 or FS5.
Since the lens has an emphasis on a small form-factor and vignetting is now easily corrected in post or even done in-camera with compatible bodies, this type of thing isn't all that big of a deal especially for photographers nowadays. Here's the same f/2 shot from above with the stock Zeiss Batis 25mm profile applied that is included within Adobe's newest version of Lightroom CC:
When it comes to video shooters, vignetting becomes a more cumbersome beast to deal with in post so you'll want to take this into consideration if you plan on picking up a Batis 25mm solely for video use.
The Batis line is most commonly approached from a potential buyer who is looking for great AF efficiency in addition to excellent optical performance. Before testing the Batis 25mm, I have been primarily relying on high-end Canon EF glass for use on my a7RII and FS7, so native AF performance is something that I was interested in testing out.
On my a7RII which harnesses Sony's newest ‘fast hybrid' AF, the performance is impressive for photos and continuous video AF. I've never had much trouble with the AF from my Canon lenses adapted via a Metabones Mark IV adapter, but they do tend to struggle in low-light whereas the Batis held steady even in harshly lit conditions.
Since it is a native lens, you'll get access to the ‘Lock-on AF' and ‘Eye AF' functionality that is lost when using a lens via a conversion adapter (minus a Sigma Art lens combined with an MC-11 adapter). All of the autofocusing I experience was near silent with no audible noise emitting from the motor so you'll be able to operate the AF functionality without in-camera audio becoming obstructed.
Switching to my FS7 which utilizes Sony's more old-school AF technology, the AF performance is significantly slower and hunts a bit in certain situations although I'd anticipate most will be manually focusing with a high-end camera such as this so the Batis 25mm likely isn't the best candidate unless you need it for a specialty shot.
For those not familiar with the term, the formal definition of Chromatic Aberration is as follows:
“the material effect produced by the refraction of different wavelengths of electromagnetic radiation through slightly different angles, resulting in a failure to focus. It causes colored fringes in the images produced by uncorrected lenses.”
In easier to understand terms, it is a phenomenon more commonly seen on cheaper glass that results in purple, green or blueish color fringing in areas where high and low contrast points meet such as a dark tree branch in front of a brightly lit sky.
Throughout my testing, I did experience some slight chromatic aberration in some of the high-contrast photos that I have captured although the level in most of them would never be distinguishable without viewing them at a 100% or greater zoom.
For example, I can locate and remove some Chromatic Aberration in the trees in the background of this photo that I shot at a local historical mansion:
It is not until I zoom in at 1:1 or greater, where I can notice minor color fringing between the branches and the image is perfectly usable for most applications without the need to correct for this.
The Zeiss Batis 25mm performs exceptionally well especially on Sony's newest mirrorless models like the a7RII and a6300 which harness its newest AF technology. I appreciate its compact, lightweight design for street photography and travel as it helps lessen the fatigue over hours of handling your camera. Personally, I'd prefer to swap out the unconventional rubber focus ring for a traditional, contoured version that isn't ‘focus by wire' even if it meant getting I'd lose of the OLED display as this is more of a novelty than a necessity.
Ultimately, I'd recommend the Batis 25mm for photographers who want a native E-mount lens that is small, high-performing and AF-ready. If you are a videographer and don't need autofocus, I think there are more affordable options on the market in other mounts which can be adapted to E-mount that won't experience the same strong vignetting or the less desirable manual focus experience.