Zeiss Batis 18 Mm F/2.8 & Zen DP-200 Dome review by Phil Rudin

The following is a guest post from Phil Rudin (http://www.uwpmag.com/). To write a guest post on SAR follow the instruction on that page.

Zeiss Batis 18 Mm F/2.8 & Zen DP-200 Dome review by Phil Rudin

Zeiss the company founded by Carl Zeiss in the mid 1800s’ is among the most renowned of lens manufacturers. The company offers a wide range of optical products ranging from vision care and medical use to camera and cine lenses. Among the Zeiss products is a line of lenses for the Sony FE mount mirrorless cameras. The Zeiss “Batis” line of auto focus lenses recently expanded
to include an [shoplink 51094]18 mm F/2.8[/shoplink] rectilinear lens of exceptional quality.

For past issues of uwpmag.com I have reviewed both the [shoplink 51095]Sony A7 II[/shoplink] with the [shoplink 51096]Nauticam NA-A7II housing[/shoplink] (issue #86) and the [shoplink 51097]A7R II[/shoplink] with [shoplink 51098]Ikelite A7R II housing[/shoplink] (issue #90). In those reviews I pointed out that the Sony A7 lens line was a work in progress and that the system lacked a quality Fisheye lens and that wide angle prime lens offerings were mostly manual focus or non-Sony autofocus/ manual focus lenses using mount adapters like the Metabones.

The Zeiss Batis autofocus lenses were specially developed for the mirrorless full-frame Sony A7 camera line. The introduction of the Batis 18 mm F/2.8 autofocus lens is a giant step forward for underwater photographers using Sony A7 systems for both still and video work. The F/2.8-F/22 lens has a minimum focusing distance of just 25 cm (9.8 inches) with a reproduction ratio of 1:9.5, with a diagonal angle of view of 99 degrees, weighing 330 g (0.74 lbs), 77 mm filter thread and completely weather sealed.

The Zeiss Batis 18 mm is compatible with all Sony E-mount cameras and has a 27 mm equivalent on APS-C cameras like the A6300. The lens has an innovative OLED distance and depth of field display on the barrel which is quite useful for landscape photography but of no use inside an underwater housing where it can’t be seen.

Zeiss is known for creating lenses with vivid and richly saturated colors, this lens definitely lives up to those exception. Zeiss T* anti- reflective coating has been applied
to all lens surfaces to help minimize reflection and improve image clarity. The lens has a rubberized manual focus ring and linear autofocus motors that are quiet, fast and quite accurate.

During my film days 18 mm rectilinear primes and the nearly equivalent [shoplink 51099 ebay]Nikonos 15mm[/shoplink] at 94 degrees diagonally were the gold standard for underwater photographers. Most modern lens manufacturers have now opted for zooms to cover this focal length and 18 mm full frame autofocus primes are now as scarce as Hens teeth.

The Zeiss 18 mm is without doubt the best wide prime lens I have ever used. The Zeiss 18 mm has excellent image sharpness all the way into the corners from F/4 on. The Zeiss Batis 18 mm is truly deserving of the legendary Zeiss moniker.
The [shoplink 51094]Zeiss 18 mm F/2.8 retails for $1499.00/£1189.00[/shoplink].

Zen Underwater DP-200mm Fisheye Dome Port

High quality rectilinear lenses will not perform any better than a “kit” lens underwater if they are not mated with a quality dome port and proper extension when needed. I am asked all the time if a particular lens will work with a port not really designed for that lens. I can’t stress this point enough, if you are going to invest in a high quality camera and lenses you need to seek out the very best port combinations to complement your lens choices. Not all port combinations work the same when shooting with the Zeiss 18 mm.

For this review I was shooting the Zeiss 18 mm with Sony A7RII 42MP in a Nauticam NA-A7RII housing and my port choice was the [shoplink 51100]ZEN DP-200 mm[/shoplink] optical glass dome port. My kit included the Nauticam N100 to N120 35.5 mm port adapter with focus/zoom knob and the Nauticam N120 by 20 mm extension.
Zen Underwater was founded in 2007 with headquarters located in Fort Lauderdale, Florida USA. Zen’s goal has been to design and develop the highest quality optical glass ports available. All optical glass surfaces are coated with a magnesium fluoride broadband anti-reflective coating to minimize reflection and control lens flare for distortion free images. I have used a verity of Zen Underwater ports since they were first introduced always with excellent results so it is no surprise to me that they are being used by hundreds of professional photographers world wide. The hand crafted Zen DP-200 (8 inch) fisheye dome port has a unique universal modular mounting system which can be adapted to Aquatica, Nauticam, Nexas, Sea & Sea and Subal housings.
The [shoplink 51100]Zen DP-200 port retails for $1399.00/£1283.00[/shoplink] and ships worldwide with a removable metal dome shade and neoprene port cover.

Field testing the Zeiss 18mm

The Zeiss 18 mm is one of several lenses for the A7R II that need to be mounted onto the camera from the front of the housing before the port is mounted to the N100 to N120 port adapter. The 20 mm port extension needs to be mounted onto the port and the locking device needs to be secured before it can be mounted on the housing. The best workflow for installing the port is to mount the camera body in the housing with the lens cap on, switch on the vacuum alarm switch, secure the rear half of the housing in place, then mount the lens, install the port and then draw the vacuum.

Once the lens and port are mounted they will need to be removed if you forgot your flash card, need a new battery or did not switch on the optical flash trigger. This process becomes quite easy after a few assemblies. The Zeiss 18 mm draws far less battery power than lenses like the 90 mm macro so battery life is much less of a problem with up to three dives between batteries changes.

For best corner sharpness with the full frame A7R II camera I would try to stay in the F/8 to F/16 range although I got plenty of expectable images in the F/5.6 to F/7.1 range as well. I found the system balanced very well with my two Nauticam 10 inch float arms and 8 inch ball arms while using two Inon Z-240 strobes. Focus was spot on without the need for a focusing light.
With the Zen port I didn’t see any reflections from the port glass often associated with shooting at or near the surface. No white lens markings
were showing up in my over/under shots and I experienced little to no flare with the dome shade in place. With a 77 mm filter you have room to spare in the N120 port.
At $1499.00/£1189.00 the Zeiss Batis 18 mm F/2.8 may not be everyone’s first choice for wide angle rectilinear but for those who have already spent $3000.00+ for a 42 MP prosumer body it may make the most sense.
By comparison the Sony 16-35 mm F/4 zoom does not focus as close as the Zeiss 18 mm and at $1350.00 for the Sony lens, with another $175.00 for the zoom gear and 50 mm port extension the Zeiss 18 mm may actually be more cost effective. Along with Zeiss class leading image quality you also get a smaller overall system size and a stellar top side lens for travel, astro, landscape and more.
Thanks to ZenUnderwater.com for assistance with test equipment for this review.

Phil Rudin
http://www.uwpmag.com/

Store links to the mentioned products:
Batis 18mm at [shopcountry 51094]
Sony A7 II at [shopcountry 51095]
Nauticam NA-A7II housing at [shopcountry 51096]
SonyA7R II at [shopcountry 51097]
Ikelite A7R II housing at [shopcountry 51098]
ZEN DP-200 mm at [shopcountry 51100]