Memory card choices are always complicated for camera owners, and for those with the new Nikon D500 the choices are even harder. The D500 has two card slots, one for a standard SDXC and the other for one of the new XQD cards, so you have to decide whether to get one card or two, and for each one you get you have speed options. The best answer, of course, is to look at cards in light of your own shooting behavior.
I’ve encountered three types of wildlife photography were speed matters. One is where you’re trying to capture an event that’s happening so fast there is zero chance you could pick a shot or two and hit perfectly. An example is a breaching whale. The second is where there’s a critical, fast-moving, activity like a lion kill, and the third where you’re trying to grab a shot at something that’s moving and elusive and you take multiple shots to be sure you have something—birds often present this situation.
In the first situation, you’d like to shoot a high-speed burst long enough to cover the whole event. In the second case, you probably don’t need high-speed bursting but you’d like two or three shots per second, and in the third you probably need a shot every second or two, but for a relatively long time.
One might think that cards wouldn’t matter a lot in the D500, at least not in most cases. There’s a widespread view that the D500 has a 200-shot butter, fostered by Nikon’s own material. Not true; the camera’s “buffer” doesn’t seem much bigger than those of earlier models, but it can write to a card faster—if the card is fast enough to take advantage of the speed.
What I wanted to do to test the cards was to test how they behaved. The easiest way to do that is to set the camera for high-speed repeat and hit the shutter, stopping when the click rate suddenly changes or ceases. That lets you see two things—how many shots can be taken at max speed before the buffer fills, and how will the camera/card then sustain shooting. I also wanted to test the cards (at least the SDXC ones) in both the D750 and the D500 to see what the difference in cameras/buffers would mean. I used a freshly formatted-in-camera card in all cases, shooting raw compressed.
Let’s start with the SDXC cards. Anyone with a DSLR should have been using Class 10 cards in the past; they were the fastest of the old scheme. Now, the speed measure is more often the UHS specification, which has both UHS-I and II and then has speed classes. See what I meant about “complicated?” Then there’s the fact that some (but not all) card vendors advertise speed as some-number-x, like “1000x”, and the fact that read and write speed to the cards are not typically the same.
A baseline can be established by taking an old Class 10 card, one from Transcend. With this card, the D500 did 38 shots in high-speed burst mode, after which it stopped shooting for at least an appreciable interval. The D750 took only 15 pictures in this scenario and also stopped at that point. You could do a whale breach with the D500, and probably with the D750 as well, though the actual burst rate on the D750 seemed to be about 5 per second rather than the D500’s ten.
Next, I used the Transcend UHS-I/3 cards, which they rate as Read 95 and write 60. These are pretty reasonably priced and they gave me the same 38 shots on the D500 at high-speed (10/second) repeat before the buffer filled. Once that happened I got about three shots every two seconds. On the D750 I still got 15 shots, but this time the camera was able to take pictures at a rate of about one every 2 seconds after the initial burst.
My second test was with Transcend’s top SDXC card (they don’t make an XQD at this point), which is a UHS-II/3 rated at 285/180. On the D500, this card let me shoot 72 high-speed images before the buffer filled, but it then seemed to continue to shoot at about 2 shots per second thereafter. This seems to duplicate other tests of the 1400x Lexar XQD cards. For the D750 I still got the 15 pictures before the buffer filled, and after that about 1 image per second could be taken.
The final test was with Lexar’s XQD professional 2933x UCS-II/3 card. This card shot 200 images as Nikon rated and stopped. But after just a few seconds you could shoot another burst of 200 images, and the card seems to sustain about 4 frames per second forever. This card doesn’t work in the D750, of course, so I can’t do a comparison test.
So what does this mean? My own experience is that with some arresting wildlife encounters, you can easily outshoot the capabilities of the older Class 10 cards. I’ve even done that taking bird pictures. My first recommendation, then, is to go with nothing worse than the Transcend 95/60 UHS-I cards. If you presume 2 to 3 shots per second low-speed repeat as your standard, then you could shoot for about 20 seconds before the buffer fills, which is probably enough for most work, and you can sustain about 0.6 frames per second more or less continuously.
The Transcend top-end card, which is 285/180, would give you about 30 seconds of shooting before the buffer fills. Better yet, you seem to be able to sustain about 2 shots/second for a much longer period—several minutes, perhaps. I think this is a workable level of shooting performance for nearly all wildlife shooting, and if the D500 held two SDXC cards, I’d go with two of these. As it is, this card is in my SDXC slot. It also seems to have a slight advantage in the D750, though I’m not convinced that the difference justifies the higher price.
The D500 doesn’t come in a two-SDXC model, though, and one of the issues with having only one card in the camera is that you can’t overflow if you run out of space. I’ve done that too—running into something demanding when you’re down to space for a hundred or so images left. So I think two cards are mandatory, which gets us to XQD. The Lexar card I tested was truly impressive in the D500, shooting a 200-frame burst and, with perhaps a five-second wait, shooting another. For action shooting this is a killer combination, far better than any of the earlier Nikon models I’ve tried.
I do want to make an important final point, which is that burst shooting isn’t for everyone. In fact, it’s not always the best strategy even for those who do need it from time to time. I think that situations that demand high-speed burst can usually be anticipated so you can set it. I think that’s harder with low-speed burst, since the alternative (hammering on the shutter to take quick images) isn’t always effective. The problem with setting low-speed burst is that you often get two shots when you didn’t want to, which wastes a lot of card space. So be sure you really need burst mode before you worry about card speeds!