Major UPGRADE // A Comparative Review of the Nikon D850 vs Z8 for Unde

By Josh Blank

Fellow Nikon shooters, the time has come to finally make the inevitable jump from DSLR to mirrorless! As a long time user of the highly regarded D850 I, like many others, have been waiting for Nikon to release a camera that truly warrants the expense that comes with transitioning between systems.

I was recently given the opportunity to try out Nikon’s newest release, the Z8, and let me tell you; this is camera we have been waiting for. If you find yourself still on the fence, keep reading while I point out some of the key features and capabilities that place the Z8 not only lightyears ahead of the D850 but firmly amongst the industry’s best cameras for underwater photography and videography.

Turtles Copyright Josh Blank Ikelite Underwater Housing Nikon Z8

F10 • 1/200 • ISO 125 • Nikon 8-15mm Fisheye with FTZ Adapter

Introducing the Z8

Simply put, the Nikon Z8 is an impressive camera that has exceeded all my expectations. In a nutshell, the Z8 is just about on par with Nikon’s flagship, the Z9, only in a much smaller and more affordable body making it the more appropriate choice for underwater users.

Despite Nikon having already released a range of mirrorless options over the past few years, the D850 has largely remained the camera of choice amongst wildlife photographers who focus primarily on stills as opposed to video. When the Z8 was released in May of 2023, Nikon shooters were ecstatic to learn about the camera that would finally give them a reason to transition to mirrorless.

This review explores the Z8 in detail while also making comparisons between the older D850. I will start by touching on key areas where this camera really excels with regards to both photos and videos before moving onto topics such as high-speed shooting, battery life and choice of lenses.

Pink Whip Rays Copyright Josh Blank Ikelite Underwater Housing Nikon Z8

F8 • 1/160 • ISO 500 • Nikon 8-15mm Fisheye

Autofocus

Autofocus is by far the biggest improvement in the Z8 and is quite simply in a class of its own when compared to the D850. The speed and efficiency in which the camera is able to lock onto, and maintain focus is amazing.

The Z8’s dynamic area focus modes (which I use almost exclusively when working with big animals) offers the choice of 3 different sized focus boxes – small, medium, and large. For species such as turtles, rays, and sharks I found the medium focus area to be perfect. For larger subjects such as a school of trevally, I opted to use the large focus area with great results.

Turtle at Surface Copyright Josh Blank Ikelite Underwater Housing Nikon Z8

F20 • 1/200 • ISO 800 • Nikon 8-15mm Fisheye

Z8 users can also look forward to improved 3D tracking and subject detection. Full disclosure, I have never been a huge fan of such modes simply because I have always preferred to maintain full control when choosing my point of focus on any given subject. With that being said, the Z8 blew me away with its speed and accuracy and made capturing faster-paced scenes significantly easier. I found the focus mode “wide area-L (large)” coupled with the “animal” subject detection mode to work very well for a wide range of underwater species. Utilizing these settings together provides a large box on the rear display screen within which the camera will actively aim to track animals that move within its boundaries.

Despite the animal detection mode being geared primarily towards topside subjects like cats, dogs, and birds, I found it still worked well on underwater species such as turtles, sharks, and most rays. So many marine encounters happen very quickly and are almost always in motion; being able to rely on fast, reliable tracking really is such an advantage.

Trevally Copyright Josh Blank Ikelite Underwater Housing Nikon Z8

F9 • 1/160 • ISO 200 • Nikon 8-15mm Fisheye

Low Light Performance

Another area in which the Z8 boasts notable improvements over the D850 lies in its ability to function very well in low light conditions. I was lucky to enjoy a few dives on the Great Barrier Reef photographing turtles both before sunrise and after sunset. At these hours ambient light is extremely limited but the Z8 didn’t miss a beat. In fact, even when shooting split shots, which can be a demanding task for cameras even in favourable lighting, the Z8 continued to find and lock focus.

Dynamic range is yet another area where the Z8 really shines. Dynamic range describes the cameras’ ability to handle scenes with both strong highlights and dark shadows. The Z8 was highly capable at just about every scenario I attempted. From shooting bright sun bursts in the early hours of the morning to capturing stunning animal portraits under the black of night – the camera consistently performed in a way that exceeded all expectations.

F20 • 1/200 • ISO 200 • Nikon 8-15mm Fisheye

Burst Shooting

If you are a fast-action shooter who relies on natural light, you will be excited to learn the Z8 is capable of firing at 20 RAW frames per second (fps) compared to the D850 which maxes out at just 7 fps. These kinds of speeds coupled with the camera’s highly responsive autofocussing just about guarantees you will never miss capturing that one perfect encounter.

If like me, you work primarily with strobes, such high shooting speeds can be overkill. With that being said, Ikelite’s DS230 strobes can in fact keep pace as fast as 10 fps depending on your chosen power settings. This is insanely fast and offers a massive advantage over not only the D850 but most camera/strobe combinations available today.

Electronic Viewfinder

Moving away from an optical viewfinder and beginning to compose images using the LCD display screen took a little bit of getting used, however, after a day or 2, you will never want to go back (at least I didn’t!). Being able to compose, shoot and review without ever taking your eyes off the screen was the luxury I never knew I needed. The electronic viewfinder also allows for much greater accuracy when “shooting from the hip” as your able to keep your eyes on the scene at all times, even when extending the camera out to get that little bit closer for a crisper, more detailed image.

Another welcomed feature that comes with the electronic viewfinder is being able to set the view mode to “adjust for ease of viewing” or “show effects of settings”. While the former is recommended when using strobes, the latter is very helpful when shooting with natural light as the LCD screen will provide a live preview of your exposure based on your chosen settings.

F11 • 1/200 • ISO 500 • Nikon Z 14-30mm F/4 S

Video

It’s no secret that the D850 and DSLR’s in general simply don’t compare with mirrorless cameras when it comes to video. For years I found myself frustrated with clunky, slow autofocusing when attempting to record underwater video and to be honest improved video capabilities was my main reason for initially wanting to make the change to mirrorless. If you are currently using the D850, the Z8’s video will be a breath of fresh air!

Setting the video focus mode to “full-time AF” ensures smooth and accurate recording. You can then choose from a variety of resolutions and frame rates including 8K/60p, 4K/120p and 1080/120p.

As a dedicated stills shooter, underwater video is not something that I have done much of over the years but after just a few months of filming some of my favourite species with the Z8, it’s hard not to be excited at the idea of beginning more video projects in the future.

Lenses

If your still shooting a DSLR and hesitant about making the jump to mirrorless, I’d be willing to bet one of the main reasons for this is the lack of native Z lenses for underwater use and the idea of using a FTZ adapter may give you pause. Well, I can confirm the adapter is seamless and does not impact focusing speeds in any noticeable way.

F8 • 1/160 • ISO 100 • Nikon 8-15mm Fisheye

The majority of the images used throughout this review were captured with the Nikon 8-15mm fisheye using the aforementioned FTZ II adapter. I was however, also given the opportunity to test a native Z lens in the 14-30mm F4 S. While I noticed no discernible difference in focusing speed as a result of not using the adapter, I did enjoy working with a rectilinear lens for a change and a slightly different aesthetic.

The 14-30mm provides a very useful focal range being able to comfortably fit large animals in the frame from close distance while also being able to extend out to capture those slightly more timid species. I also found the lens to be capable of focusing very close for highly detailed portraits; something that I’m sure fellow big animal photographers will be excited to know!

F9 • 1/200 • ISO 250 • Nikon Z 14-30mm F4 S

Battery Life

One of the last remaining advantages of a DSLR over a mirrorless camera is undoubtedly their impressive battery life. With the Z8 being listed at just 330 shots per charge compared to the D850’s 1840, I must admit I was worried that this may be a deal-breaker for me. Despite these reviews online, which are based on very particular testing parameters, I found real-life use to far exceed this. In fact, while reviewing the Z8 set to shooting at 5 frames per second and using the rear LCD display screen to compose images, I averaged anywhere from 300-400 images and 10-15 short videos per session and never saw the camera drop below 48%.

F9 • 1/200 • ISO 100 • Nikon 8-15mm Fisheye

Ikelite 200DL Underwater Housing

I have been a user of Ikelite housings ever since beginning underwater photography in 2016. When it comes to the Z8 housing, divers can expect the same exceptional quality and user-friendly ergonomics as we have become accustomed to over the years.

One exciting addition is an optional bulkhead that enables charging and/or data transfer through the housing. As somebody who despises the daily task of taking apart and reassembling my equipment on a dive trip, this was amazing! Unlike most other camera’s however, the Z8 can only manage either battery charging OR data transfer. I chose to connect for battery charging which allowed me 3 full days of carefree shooting before filling my 128GB card and having to open the housing to download files. If you wanted to extend this even further, the Z8 accepts 2 memory cards and while I personally prefer to set my secondary card to backup, you can instead set this to overflow doubling the amount of storage available and also the time required before needing to open up the housing. Obviously you can also choose to shoot a larger sized memory card too.

Josh Blank USB Charging Nikon Z8 in Ikelite Underwater Housing

The camera can be charged while still in the housing using the optional USB-C Charging Bulkhead.

Another feature of the Ikelite housing which I found particularly well designed was the easy-to-operate dial to switch between photo and video. A simple twist between your thumb and index finger is all that’s needed and with the Z8 maintaining previous settings for each mode, I found jumping between photo and video to be quick and easy.

If upgrading from an older housing, you will find that Ikelite has also improved ergonomics by adding new dial knobs that allow for greater grip. Ikelite is renowned for always looking to improve their products and even simple modifications like this, make such a difference when adjusting settings underwater.

Shovel Nose Ray Copyright Josh Blank Ikelite Underwater Housing Nikon Z8

F8 • 1/200 • ISO 64 • Nikon 8-15mm Fisheye

Size and Weight

Generally speaking, the smaller and lighter the system, the more suitable it is to take underwater. The Nikon Z8 is roughly 10% lighter than the D850 as well as being slightly smaller in both length and width. Despite these differences being somewhat small on paper, they are quite noticeable when carrying your equipment for long periods of time onto dive boats, manoeuvring the system underwater or when trying to fit everything into a suitcase to avoid excess baggage charges!

What Are You Waiting For?!

I must admit, I felt a little biased when writing this comparison review with non-stop praise for the Z8 with really no complaints… But the fact is, there is no comparison between the 2 cameras. The Z8 is a significant step up in all areas with exception to battery life which in my opinion remains more than adequate and is even less of a concern given we can now charge through the housing with the Ikelite USB charging and data transfer Bulkhead. As a long time D850 advocate, it took me just a couple of hours into shooting the Z8 to make up my mind – Nikon shooters; it’s time to go mirrorless!

Gray Nurse Shark Copyright Josh Blank Ikelite Underwater Housing Nikon Z8

F8 • 1/200 • ISO 200 • Nikon 8-15mm Fisheye

Josh Blank is a diver and underwater photographer based out of the Gold Coast on the east coast of Australia. Through a combination of scuba diving and freediving, Josh is passionate about exploring the open ocean and photographing the larger marine species that inhabit the deep blue. With his photography he hopes to inspire, inform, and instill an interest in the underwater world. Read more...