If you are looking for a lightweight full-frame lens with very wide field of view, fast autofocus and large aperture for landscape, astro and architectural photography, the third member of the Batis family may be the ideal lens for you. On top you get dust and spray protection.
After the felicitous Batis 25 and Loxia 21, I was very curious to see, what level of excellence ZEISS can deliver in the 18mm focal length range. As you may already know, Batis lenses are developed specifically for the short flange distance and filter stack of Sony's mirrorless full frame E-Mount cameras, the Alpha7-series. In contrast to the Loxia line, the Batis line comes with fast autofocus and an OLED display providing information about distance and depth of field when using the manual focus option. The Batis 18 incorporates a Distagon floating elements design with 11 elements (several aspherical and special glass). Despite that complexity it comes in a compact housing and weighs only 330g. Click here for further details.
ZEISS Batis 2.8/18 on Sony A7RII
Bokeh
Usually I start my reviews with a deeper look into sharpness / details. This time I will focus on bokeh first, as there are not many super wide angle lenses starting with an f/2.8 aperture. Despite other ultra wide lenses like the Voigtlander 15mm f/4.5 or the Zeiss FE 16-35 f/4, the Batis 18 still provides some options to play with depth of field arranging an object sharply in the close-up range with a nice background blur.
A first example you can see already as title image fo this article, here are further samples at f/2.8:
Tiburtiusbrunnen, Straubing, ZEISS Batis 2.8/18 @ f/2.8
Tower Bridge Bokeh - ZEISS Batis 2.8/18 @ f/2.8
Sharpness
Shortly: The Batis 2.8/18 provides incredible detail across the full frame right from open aperture. Period.
You need some proof? Let's start with some examples in available light conditions where you might prefer a large aperture (you can click on the images in order to open the flickr page for EXIF and further sizes including full resolution):
Sankt Jakob Straubing, ZEISS Batis 2.8/18 @ f/2.8 (handheld at 1/20s, bottom cropped for 16:9 format)
ZEISS Batis 2.8/18 @ f/2.8 (bottom cropped for 16:9 format)
Pub (minor HDR) - ZEISS Batis 2.8/18 @ f/2.8
Slipstream - ZEISS Batis 2.8/18 @ f/2.8
When you look into 100% resolution (1:1 actual pixels) you may see some minor color fringing at strong contrast edges of the roof-lights. If you have enough light to stop down, even those minor aberrations disappear.
London City Hall - ZEISS Batis 2.8/18 @ f/8 (bottom cropped for 16:9 format) - please note, that the city hall distortion is NOT caused by the lens ;-)
City Hall Details, London - ZEISS Batis 2.8/18 @ f/5.6
Girl with a Dolphin Statue at Tower Bridge, London - ZEISS Batis 2.8/18 @ f/8
You can find some further examples in this album: https://www.flickr.com/photos/hhackbarth/albums/72157667511545211
Conclusion
The Batis 2.8/18 demonstrates an impressive level of optical performance that can be achieved in a compact and lightweight mirrorless full-frame system. Although at the time of this writing there are no lens correction profiles available in Lightroom / Adobe Camera Raw for this super wide angle Batis, I see no demand for it as the results were almost free from distortion and vignetting. Only at open aperture you may see a need to correct some minimal CA at extreme contrast edges. Resolution, contrast and color richness are excellent even when you shoot against direct sun light. The autofocus works fast and reliable, it may be helpful especially at open aperture when playing with depth of field in the close-up range. This lens is simply amazing!