I wrote, two years ago, that I thought the distinction between DSLRs and mirrorless cameras would disappear. Not that mirrorless would eclipse DSLRs, more that the differences would reduce to the point that the presence or absence of a mirror becomes the least relevant part of a discussion of two cameras.

As I was writing a comparison of the Sony a7R III and Nikon D850 today, I was suddenly struck by the realization that it might have already happened. I think there are a lot of interesting differences between the two cameras but very few of them have anything to do with the way we’d tend to categorize them.

With this in mind, my gear of the year is the Sony NP-FZ100. Or, to those of you not obsessed with product codes, the a9 and a7R III’s battery. The simple reason for this is the role it plays in rendering the difference between mirror-less and mirror-full cameras moot.

Good enough: the threshold beyond which any further excess is superfluous

It all comes down to the idea of ‘good enough.’ And please don’t misunderstand me, I’m not talking about accepting the mediocre or tolerating the barely sufficient. Instead I’m referring to the threshold beyond which any further excess is, if not excessive, then at least superfluous: it offers no practical benefit.

Once I have enough battery life to get me through a demanding day of shooting, then any extra left in the tank is all very nice, but not exactly necessary. I recently spent a morning shooting both stills and video of a cyclocross race with the a7R III. Shooting a mixture of JPEGs, uncompressed Raws and 4K video, I comfortably churned out more than the 64GB capacity of my memory card and had to switch to a second. What I didn’t come close to doing was running the battery out. At the end of the racing, I still had more than 27% charge left, despite the sub-10°C temperatures.

The move to the 'Z-Type' battery on the right is the difference between me having to worry about charging and carrying spare batteries and me never having to think about it.

This suddenly eliminates the constant battery anxiety I’ve always felt with previous Sony mirrorless cameras (and that's without including the RX1R II, an otherwise fabulous camera whose butterfly-like lifespan prompts even its proponents joke “it’s like shooting film: you need to think about what you’re going to do with your 36 exposures”). Because when I’m shooting, I don’t ever want to be worrying about whether I’ve brought enough batteries, and which ones are charged. I don’t even want to have to think about it.

In fairness Panasonic got here first, having put a big battery in its GH models as far back as the GH3, but I didn't notice it to the same extent because I was primarily shooting video with those models.

This eliminates the constant battery anxiety I’ve previously felt with many mirrorless cameras

More demanding shooters, be they photojournalists or longer-form filmmakers, can always attach a battery grip for longer duration, but for me, the FZ100 means the a7R III is able to surpass my ‘good enough’ threshold. So, while the D850 can boast a very impressive 1840 shots per charge, for me and my photography, that’s well into the territory of overkill.

So, as a technology that allows mirrorless cameras (hopefully of all brands) to offer the same practical benefits as their DSLR rivals, my gear of the year is a battery. Because it makes the a9 and a7R III into significantly better cameras, not just because it pulls another leg out from under all those tired ‘mirrorless vs DSLR’ arguments.