Fully Electronic Shutter
The Nikon Z9 omits something that every Nikon interchangeable lens camera has had since the dawn of time: a shutter curtain.
Instead of a physical curtain opening and closing for every photo, the Nikon Z9 exclusively uses the electronic shutter. Electronic shutters are nothing new for Nikon, but so far, they’ve always come with some compromises, and it’s been necessary to use the mechanical shutter for certain subjects.
Nikon Z9 Electronic Shutter Readout Speed
What is it about electronic shutters that can lead to problems? The underlying issue is readout speed. With an electronic shutter at a fast shutter speed – say, 1/4000 second – each pixel only “sees” the outside world for 1/4000 second. However, not every pixel is exposed simultaneously. Simultaneous exposure is only possible on a camera sensor with a global shutter, which you’ll only find on a few highly specialized cinema and astrophotography cameras.
Instead, with most electronic shutters, some pixels are exposed sooner than others, even though all of them receive the same 1/4000th-second duration of light. The last pixel may be exposed a good bit later than the first, maybe 1/15th of a second later. That may not sound like much, but it’s enough of a difference that a fast-moving subject could be in a very different place when the final pixel was exposed.
This difference won’t cause motion blur (after all, each pixel is still only exposed for 1/4000 second, freezing motion). However, it will cause your subject to warp, in an effect known as rolling shutter. Essentially, it looks like this:
Electronic shutters can also have issues when photographing artificial light. When the light source flickers at a high frequency (like most artificial light) instead of being continuous or flickering slowly (like a candle), it can look like this:
All of this is why, in the past, I’ve recommended using a mechanical shutter whenever there are fast-moving objects or artificial lights in your photos. I have a whole article on mechanical vs electronic vs electronic front-curtain shutters that dives into these issues (and a few other minor ones) in detail.
Does this mean that Nikon made a mistake to eliminate the Z9’s mechanical shutter? I was worried about it at first, but the reality is very impressive. Here’s the Nikon Z9’s take on the same fan going at top speed, for example:
I promise, the fan really was spinning at full speed! But you wouldn’t know it from the lack of rolling shutter in this picture.
How did Nikon manage such a good result with an electronic shutter? It’s all because of the Z9’s readout speed. Unlike most other cameras on the market, the Z9’s electronic shutter has a speedy 1/270 second readout speed (thanks to Jim Kasson for his detailed tests showing so).
There is also little to no issue with banding from artificial light on the Nikon Z9, and the automatic 50 Hz and 60 Hz light source detection works flawlessly in my experience. For particularly tricky types of artificial light, you can even manually tune the Z9’s shutter speed by tiny fractions of a second (up to 1/96th of a stop of light) in order to eliminate flickering.
As a result, the Nikon Z9 has minimal issues caused by eliminating the mechanical shutter curtain. It’s an unorthodox approach, but I think it was the right choice for this camera.
The bee’s wing here is the only case where I’ve seen rolling shutter on the Nikon Z9 – and a DSLR would have shown it here, too. (Just look at my shutter speed of 1/8000 second, and yet the bee’s wings are moving so fast that they’re still blurry!)
Nikon Z9 Shutter Sounds
Because the Z9 doesn’t have a mechanical shutter curtain, it has the interesting property of being an entirely silent camera – at least if you want it that way. I don’t mind silence for photographing landscapes, and some types of photographers will adore this about the Z9, but others might find it disconcerting.
That’s why, by default, the Nikon Z9 plays a low, quiet shutter sound through its speakers each time a photo is taken. It’s a reassuring sound that allows photographers to determine the camera’s rough shutter speed and burst rate by ear (although the sound maxes out at 30 clicks per second). I think most photographers will be happy to leave the sound on. You can adjust the volume and pitch in the setup menu.
Nikon even teased the possibility of adding unique sounds to the Z9’s shutter in future firmware updates, like meows and woofs. It’s a gimmick, and one the Z9 may never get in the first place. But maybe there are some pet photographers and child/family photographers who will find it helps draw their subject’s attention!
Visual Confirmation as a Photo Is Taken
Another quirk of the fully electronic shutter is that the Z9’s viewfinder and LCD don’t necessarily go dark every time you take a picture. As I discussed in the EVF section of this review, so long as your shutter speed is faster than 1/6 second, and you’ve selected “view all in continuous mode” in the shooting/display menu, you won’t see any blackout.
This is another thing that some photographers will love (sports/wildlife photographers in this case) and others may find disconcerting. If you prefer, Nikon allows you set the Z9’s screen to briefly go black every time a photo is taken, or (my preference) flash a thin, black line around the border of the image in the viewfinder/LCD.
Sensor Dust Protection Curtain
Since mirrorless cameras have a more exposed camera sensor than DSLRs, in my experience, they tend to accumulate unwanted dust particles more quickly. Some mirrorless cameras, including many of Canon’s EOS R cameras, solve this problem by closing the mechanical shutter curtain every time the lens is removed. It’s a brilliant solution to an irritating problem – but, of course, the Nikon Z9 lacks a shutter curtain.
That’s why I was so glad to see that Nikon added a dedicated sensor-protection curtain to the Z9 anyway! They easily could have foregone this expense, but instead, the Z9 has a sturdy cover to protect the sensor. Changing lenses in dusty conditions is still something I’d try to avoid, of course. But at least with the Z9, no dust will fall on the sensor – or on the important shutter curtain! – when you change lenses.
Conclusion
All in all, I applaud Nikon’s decision to remove the mechanical shutter on the Z9, and I hope to see the same in other Nikon cameras in the future. That said, it only succeeds because of the Z9’s fast readout speed (which is possible thanks to the camera’s stacked CMOS sensor design). If Nikon can’t approach the Z9’s readout speed on other cameras in the future, they will have no choice but to add a mechanical shutter curtain to those cameras.
On the next page of the review, I’ll cover the ISO performance of the Nikon Z9. So, click below to go to “High ISO Noise + ISO Invariance.”