Nikon Z7 Weather Testing
Nikon Z7 / Nikon Z6 Weather-Resistance Test Results
Very well-sealed, weather-resistant full-frame mirrorless cameras
by Dave Etchells | Posted: 05/04/2019
Imaging Resource's weather-testing approach
This is one of an ongoing series of weather-resistance tests of camera systems. Manufacturer claims about weather resistance are all over the map, in part because there's no established standard that's relevant to how photographers actually use cameras. Our aim is to establish a consistent basis for comparing weather resistance between cameras in a way that makes sense for photographers. If you're interested in the details behind the tests, you can read the loooong article I wrote about the rationale behind our camera weather-testing approach.
Camera tested: The Nikon Z7
The Nikon Z7 was announced in late August 2018, along with the Z6, as Nikon's first entries in the full-frame mirrorless market. The Z7 is their current flagship mirrorless model, but the Z6 shares the same physical design, so our results here should apply equally to that model as well. Nikon represents both cameras as being "weather resistant", even calling attention to that feature in their marketing.
We performed our tests with the Nikkor Z 50mm f/1.8 S lens attached. All Z-mount lenses have a gasket around their flange that seals against the camera's flange, to prevent any water from getting inside via that route. We're told that Z-mount lenses themselves also have internal sealing of a similar level to that in the camera bodies.
Visible weather seals on the Z7
We don't currently disassemble the cameras we test, so we can only comment on the weather seals that are visible when you open the various compartments and peel back the port covers.
This is more a function of the lens in use than of the camera itself, but in the case of the Nikon Z system, all the lenses have similar sealing, namely a thin gasket made of fairly stiff plastic that surrounds the lens flange and seals against a flat part of the camera flange itself.
This shot shows the mount end of the Nikkor 50mm f/1.8S after a 35 minute water test. The water you see on the mount was almost certainly dragged in as we removed the lens from the body, as opposed to having leaked there during the test itself. This was one of the earlier tests we did; we've learned since then to remove lenses very slowly, to avoid creating a suction as the lens separates from the body.
(A note for all of you: A surprising amount of water can wick into the crevice between the body and the lens barrel, even when there's an effective gasket blocking the water from leaking into the camera when the lens is attached. When you remove the lens, though, all that water that's wicked into the crevice can get pulled into the body. If you've been shooting in the rain, it's a good idea to (a) use a soft cloth or paper towel to get as much water out of the lens/body gap as possible, and (b) once you've twisted the lens loose, separate it from the body very slowly. This avoids creating suction that can pull water into the body.)
The Z7's battery compartment seems to be quite well sealed, with a continuous seal around the perimeter of the lid, made of what seems to be an impermeable, soft silicone rubber compound. The seal dips down a bit where the latch mechanism is, but it seems to be a continuous surround, made of a pretty impermeable material. (This as compared to the open-cell foam that's more common in camera seals, and that the Z7 itself uses around the memory card compartment door.)
Memory card compartment
The Z7's memory card compartment has foam gasket material around the edges of the door opening. It's an interesting design, with a U-shaped gasket around the front and up the two sides, and then a strip at the rear. Closing the door is a two-step process, first folding it down snug against the body, and then pressing to snap it inward. We can't see the full extent of the U-shaped seal without removing the door itself, but it seems likely that it runs all the way back. When the door is closed, a thin rim or lip on the door presses against the U-shaped seal, and when the door is snapped back into the fully-closed position, the rear of the door flap presses against the foam seal at the back. This seems like a pretty solid gasket design, provided that the U-shaped seal's rear legs mate tightly with the rear seal.
The port covers on the Z7 are two flaps that fit pretty tightly over the ports themselves. Each port has a raised ridge around it on the camera body, and the stiff-but-flexible plastic flaps press firmly over them, creating tight seals around each port opening. It seems like a very secure seal design.
The Z7's flash hot shoe has only the relatively large electrical contacts that connect to the bottom of the flash's foot, and don't seem prone to being fooled by the slight conductivity of rainwater. The hot shoe is covered by a hard plastic protective cover that will guard against getting general schmutz on the contacts, but which doesn't provide any sealing against water getting on them. As noted, though, this doesn't seem to matter, as the shoe connection doesn't have the sort of fine accessory contacts that we've seen cause problems for some cameras that use them.
Water exposure tests performed on the Z7
Our baseline weather testing protocol currently involves exposing cameras to simulated rainfall at a rate of 1 cm/hour (or just a smidgen under 0.4 in/hour) for 35 minutes, while actuating the camera controls according to a set script. (Our thought being that seals around moving components are more likely to leak when the parts they're sealing are moving relative to each other.) For cameras that successfully pass this test, we give them a double-dose of 70 minutes the following day, to see if they can withstand what most people would consider very heavy exposure.
(For reference, meteorologists refer to rainfall rates greater than 0.75 cm/hour (0.3 in/hour) as "heavy rain". So our test at 1 cm/hour represents a significant level of rainfall, although it's far from what you'd see in the tropics or a thunderstorm. I suspect that few amateur photographers would probably stand out in a rainstorm like this for more than 30 minutes at a time, so it seems like a good test for cameras that claim weather resistance, and in fact does seem a good level for separating levels of resistance in higher-end camera models. We plan to extend our tests to cover lower-end cameras at lower precipitation rates in a system using custom-designed dripper nozzles, but that's some ways off in the future yet.)
In the case of the Z7, we exposed it to the 35-minute protocol, and found that it did quite well. We put it in our drybox overnight, and then gave it an additional 70-minute exposure the next day.
As noted, the Z7 did very well in our testing, with little evidence of problems during the tests themselves. We found the following, in both the 35-minute and subsequent 70-minute tests. (No difference in behavior was observed between the two.)
Touch-screen was unreliable/unusable
This is extremely common; the touch-screens on all cameras we've tested to date having the feature become either unresponsive or very unreliable when wet. This is likely because the water greatly changes the capacitance of your fingertip, so the electronics have a hard time telling where you're pressing, if they're able to detect a touch at all. You need to set your camera up in such a way that you're not relying on the touch-screen to operate it, if you expect it to get wet while shooting.
Viewfinder eye-detect sensor triggered falsely in face-down position
This is also very common. Many cameras use a small infrared sensor next to the viewfinder eyepiece to automatically switch between the rear LCD and electronic viewfinder when you hold the camera to your eye. A drop of water on the surface can reflect light back into the sensor, fooling it into thinking that you're looking through the eyepiece. Different cameras are more or less sensitive to this, and the Z7 seemed less so than many, with the eye sensor only triggering falsely when the camera was in the face-down position as if slung from a neckstrap. The problem cleared itself when the camera was returned to a normal vertical orientation, allowing the water to drain off. If you're going to be shooting where drops of water can strike the eye sensor, we recommend disabling automatic viewfinder-switching, using a manual control to do so instead.
And that's pretty much it, in terms of any functional issues. All the controls worked as intended, and we were able to operate the camera with complete confidence, even through the second double-dose of rainfall. In total, the camera saw 105 minutes of "heavy rainfall" across two days, and other than the largely-unavoidable problems mentioned above, it performed flawlessly.
As noted above, the Z7 performed flawlessly during the water exposure itself. Opening it up, we didn't find any overt water -- that is, visible drops of water -- anywhere, but did find a small amount of condensation on the inside of the battery compartment door. Here's a rundown of the post-exposure findings:
Lens flange and shutter/sensor box
As noted earlier, we're learning to remove lenses verrry slooowly after a weather test, to minimize water trapped in the crevice between the lens and body getting pulled further onto the flange due to the slight suction that happens as the lens is pulled off. We also try to remove as much of the wicked water as possible before opening, by pressing a paper towel or microfiber cloth tightly into the lens barrel/body gap.
We weren't quite slow enough in opening the Z7 body on the cycle these shots were taken from, so there's some water on both the lens mount and the body flange themselves. We're 100% certain, though, that this was strictly caused by the water caught in the lens barrel/body crevice being sucked in when we removed the lens.
Inspecting the body closely, we were initially concerned by what looked like a few wet areas just inside the lower rim of the flange. When we looked closely, though, it became clear that what were seeing was just some adhesive that had spread into that area during the camera's assembly. This was confirmed by the fact that the darker areas we saw didn't go away over time, as the camera dried out, and they didn't smudge when we gently wiped at them with a Kimwipe. (The fact that they didn't smudge at all meant it was almost certainly a fully-set adhesive, rather than oil or some other substance.)
Memory card slot
No signs of water anywhere inside the compartment, or on the memory card itself when removed.
Port flaps and covers
As noted in the photo caption above, there was a small amount of water on the camera body itself, but outside the area protected by the lips around each I/O port. (And even there, the little bit of water that was present was likely just wicked in as we pried the flaps open after the test.)
I saved this for last, as there was a bit more to discuss. As mentioned earlier, the sealing around the battery compartment door itself seems very good; it's a closed-cell, soft, rubbery sort of material, so won't be prone to absorbing moisture or allowing it to pass through in the course of longer water exposure.
We found no sign of water inside the battery compartment or on the battery itself. The battery compartment is where we often find water in cameras that are less well-sealed than the Z7. The top-right control cluster on most cameras is where the most-used controls are located, including the shutter button, various quick-access buttons for things like exposure compensation, sensitivity or other frequently-used functions, and typically front/top and rear control dials for setting things like aperture and shutter speed, or scrolling through menu entries. There are a lot of interfaces between things that have to move and the camera body, so a lot of seals are needed, and ones that can handle motion between the surfaces they're sealing against. When water gets in through one of those routes, it often ends up in the battery compartment.
While we saw no "overt" water in the battery compartment, after our long 70-minute test (which as noted above came the next day after the camera had already seen our standard 35-minute test), we did find some small amounts of condensation on the metal shield attached to the inside of the compartment door. We also saw this with the Canon EOS R, and it suggests that some amount of water got somewhere inside the body, and the warmer environment in that area caused it to evaporate and eventually condense on the metal door shield.
It's hard to say just how much water might have ended up inside, but the amount condensed on the battery door was a really small amount, certainly a fraction of a milligram.
Given that the camera showed absolutely no signs of malfunction during even the very prolonged water exposure, we have to say that the amount of water represented by this condensation is insignificant. We'd have no concern using the Z7 in even heavy rain for a couple of hours at a time. (It may well be able to withstand even longer water exposure, but our current protocol is not to go beyond the 35 + 70 minutes of testing with any cameras.)
Summary: How weather-resistant is the Nikon Z7?
Overall, the Nikon Z7's weather sealing is at the very top of the class among full-frame mirrorless cameras we've tested to date. In our tests, it handled heavy rain for a total of 105 minutes. (Which was the natural end of the test cycle; we didn't stop because of any problem with the camera.) After that very heavy water exposure, we found only tiny, secondary indications of any water incursion at all, and the camera exhibited no operational problems during the water exposure other than the unavoidable ones with touch-screens and viewfinder eye sensors that are simply the result of how such components operate.
Bottom line, the Z7 is the best-sealed full-frame mirrorless camera we've tested to date, withstanding heavy simulated rainfall for almost two hours. It may well be able to hold up even longer than that, and should be able to withstand more moderate amounts of precipitation for significantly longer periods.