Cards and Getting Files Off the Camera

The kingfisher left its perch for the last time a little after six, and by dark the CFexpress card in the first slot holds about two thousand raw frames. The SD card in the second slot holds nothing new, because the camera was set to Overflow and the first card never filled. Neither card should be formatted for tomorrow's walk until those frames live somewhere else.

Two thousand frames of High efficiency★ raw come to roughly 34.6 gigabytes. Moving them is the easy part. The part that matters is the order of work: which copies exist, on which drives, before any card is wiped. How long the copy takes is set less by the camera than by the slowest piece of hardware the files pass through on the way.

Page numbers in parentheses point to Nikon's Z6III Reference Guide, edition 09, which matches firmware 2.00.

First-Day Setup put the cards in and formatted them, and Card Slots and File Handling decided what each slot records and how the camera names folders and files. This chapter starts where the shoot ends. It covers looking after the cards, copying files off them by reader, by cable or over a network, working out how long that takes, and an evening routine that keeps two copies before a card goes back in the camera. Sending pictures to a phone over Bluetooth and Wi-Fi belongs to SnapBridge, Nikon Imaging Cloud and the Authenticity Service.

01.Format in the Camera, and Last

Formatting is the camera writing a fresh, empty index onto the card, the file system that records where each file sits. First-Day Setup explains the file system and the difference between a quick and a full format, so only the rules that bear on offloading appear here.

Nikon says plainly not to format cards in a computer (p. 45), and to reformat in the camera any card that was formatted in a computer or in another camera (p. 808). One reason is concrete. A single file of 4 GB or more, which a video clip can reach, can only be saved to a card formatted as exFAT, one of two common file-system formats, and not to one formatted as FAT32, the other. Nikon's fix is a card larger than 64 GB formatted in the camera (p. 928). A computer left to choose a format for itself may not choose the one the camera needs.

Formatting erases everything on the card, and it cannot be undone, so Nikon tells you to copy anything you want to keep first (p. 808). That includes pictures you protected in playback, which a format wipes along with the rest (p. 245). While the message "Formatting memory card." is on screen, do not turn the camera off or take the card out (p. 808).

The consequence for this chapter is an order of work. Formatting is the full stop at the end of the evening routine, never the first thing done to a card that came home full.

02.Handling Cards

The memory card access lamp sits on the back of the camera (p. 50) and lights while a photo or a video is being recorded (pp. 105, 108). Nikon's list of things not to do while a card is being formatted, written, erased or copied to a computer is short and absolute. Leave both cards where they are, keep the power on, keep the battery in and keep any mains adapter plugged in (p. 45). Breaking any of those rules can lose the data or damage the card or the camera (p. 45).

To take a card out, check that the lamp is off, turn the camera off, then press the card in so that it springs out (p. 96). Turn the camera off before putting a card in as well (p. 93). A card can be hot after a long session. If the high-temperature warning is on the display, wait for it to clear before reaching for the card, because a hot card is easy to drop (p. 96).

The metal contacts are the part to protect. Keep fingers and metal objects off them, never force a card into its slot, and do not bend, drop or knock a card (p. 45). Water, heat and direct sun are on Nikon's list too (p. 45). If a card that took a knock later brings up "Cannot access this memory card. Insert another card.", Nikon's first checks are whether the camera supports the card and whether a different card works. If the error survives several attempts at taking the card out and putting it back, the card may be damaged (p. 926). Copy whatever can still be read before trying anything else.

03.The Card Is Read-Only to Your Computer

Suppose you put the card in a computer, open a JPEG from it in a photo editor, crop it and save over the original. Back in the camera, that picture may now bring up "Cannot display this file." Nikon traces that message to a file changed by a computer program or one that does not follow the DCF file standard, and its instruction is not to overwrite pictures using computer applications (p. 927). DCF 2.0 is one of the file standards the camera lists in its specifications (p. 999), and a file renamed or re-saved on a computer can fall outside it.

The safe rule follows from that. A computer reads from the card and never writes to it. Copy the files off, edit and rename the copies, and leave deleting to the camera, by formatting at the end. The exceptions are files Nikon tells you to place on the card, such as a firmware update (Firmware and Updating) or a root certificate for an FTPS server, which goes in the top level of the card outside every folder (p. 893). Those sit beside the picture folders and leave them alone.

Video has one extra caution. Do not copy videos from a card while it sits in some other camera, of another brand or another Nikon model, because the videos may be deleted rather than transferred (p. 326).

What arrives on the computer is the camera's own folder and file names, unchanged. Card Slots and File Handling covers them: numbered folders such as 100NZ6_3, files such as DSC_0001.NEF, the three letters that File naming lets you put in place of DSC (pp. 455, 582), and Custom Setting d9, which keeps the numbers running across folders and cards (pp. 671-672). Two of those settings pay off at this stage. With d9 On, duplicate names become rare rather than impossible, because after 9999 numbering restarts at 0001 in a new folder (pp. 671-672), every five days at two thousand frames a day. With your initials set in File naming in both the photo shooting and video recording menus, files from your camera and a friend's never collide in one folder.

04.Two Ways Off the Card

A card reader is a small device, or a slot built into a computer, that lets the computer read a memory card directly, the way it reads a USB stick. The other way leaves the card in the camera and runs the supplied USB cable from the camera to the computer (p. 323). Both put the same files on the same drive. They differ in speed, in what they ask of the camera and in what can go wrong.

Through the Camera

Nikon's own route uses Nikon Transfer 2, a part of NX Studio, which comes from the Nikon Download Center (pp. 33, 323). Install the current version, because Nikon warns that older ones may be unable to copy pictures from this camera (pp. 33, 323).

With the camera off and a card in, connect the cable, then turn the camera on. Nikon Transfer 2 opens, or you open NX Studio and click Import, and Start Transfer copies the pictures. Turn the camera off before unplugging the cable (pp. 324-325). On a Mac where Nikon Transfer 2 does not open by itself, Nikon's fix is to start Image Capture, the import program that comes with macOS, and tell it to launch Nikon Transfer 2 whenever the camera is plugged in. Windows may show an AutoPlay prompt instead, where you pick Nikon Transfer 2 (p. 326).

Plug the camera straight into a port built into the computer, not into a USB hub or a keyboard (pp. 326, 1006). Keep the plug straight going in and coming out, switch the camera off whenever the cable goes in or comes out, and never turn it off or pull the cable while files are moving (p. 326). Nikon also asks for a fully charged battery so that the copy is not cut short (p. 326). Batteries and USB Power and Heat, Power and Recording Limits cover running the camera from USB power instead.

Two menu items govern the cable. USB in the network menu should stay at its default, MTP/PTP, the setting for computers (pp. 871, 900). The iPhone and USB-LAN choices both switch off powering and charging the camera over USB, and iPhone also switches off the camera's network functions (p. 900).

USB connection priority in the setup menu picks between Upload, the default (p. 806), which keeps the monitor dark while the camera is connected, and Shooting, which keeps it lit. Nikon warns that transfers may slow down with Shooting, and with Upload when a half-press of the release button wakes the monitor (p. 849). Leave it at Upload and leave the camera alone while it copies.

Through a Card Reader

Nikon names the reader as an alternative in its own transfer instructions, as long as the card is compatible with the reader (p. 324), and repeats the compatibility point beside its list of approved cards (p. 1011). Its troubleshooting pages go further. If a computer's operating system will not accept pictures from the connected camera, the remedy offered is to copy them with a card reader (p. 919).

The two cards need different slots in the camera (p. 93), and a reader is no different: the CFexpress card needs a CFexpress Type B slot and the SD card an SD slot, whether in two readers or in one reader with both. Lexar's pages pair each card with that kind of reader. The reader is also where card speed shows up. Lexar rates the 2000x SD card at up to 300 MB/s read and says the highest speeds need a UHS-II reader. It rates the SILVER CFexpress 4.0 card at up to 3,600 MB/s read and says that figure also depends on the reader. Its explainer on CFexpress 4.0 puts the fourfold gain over CFexpress 2.0 on a compatible USB 4.0 reader.

I prefer the reader. The camera stays off, its battery is not involved, nothing depends on Nikon Transfer 2 starting, and only a reader can read the CFexpress card faster than the camera's own USB port allows. The next section puts numbers on that.

05.How Long an Offload Takes

Start with tonight's card. Nikon gives about 17.3 MB as the size of one High efficiency★ raw file, measured under conditions it lists, among them Continuous H (extended), the FX image area, SDR tone mode and the electronic shutter (p. 1012). Real files vary with the scene (p. 1013), so the figure is an average to plan with. A megabyte here is a million bytes, the unit card makers print and the one Card Slots and File Handling uses, so 1 GB is 1,000 MB and 1 TB is 1,000,000 MB.

Write $N$ for the number of files, $s$ for the size of one file in megabytes and $D$ for the data to move in megabytes, so that $D = N s$. Every part the files pass through has a top rate in megabytes per second. Call them $r_{\text{card}}$ for how fast the card can be read, $r_{\text{link}}$ for the reader or cable and the port it plugs into, and $r_{\text{drive}}$ for how fast the computer's drive can write. The copy cannot run faster than the slowest of these, so the rate that counts is the smallest, $r$, and the time $t$ in seconds is

$$t = \frac{N s}{r}, \qquad r = \min\left(r_{\text{card}},\ r_{\text{link}},\ r_{\text{drive}}\right)$$

Each rate below is a ceiling, the best that part can manage, so each time computed from one is the shortest the copy can take. Real copies take longer.

For tonight, $N = 2000$ and $s = 17.3$, so

$$D = 2000 \times 17.3 = 34{,}600 \text{ MB}$$

Read in a UHS-II reader, an SD card with a 300 MB/s ceiling sets the pace, and the copy takes

$$t = \frac{34{,}600}{300} \approx 115 \text{ s}$$

which is a little under two minutes. In a CFexpress 4.0 reader of the compatible USB 4.0 kind that Lexar specifies, the SILVER card's 3,600 MB/s ceiling gives $34{,}600 / 3{,}600 \approx 9.6$ seconds, provided the drive can take the data that fast. Lexar's own example rate for a CFexpress 2.0 transfer, 900 MB/s, gives $34{,}600 / 900 \approx 38$ seconds.

The camera's port is harder to price, because Nikon publishes no transfer rate for it. The specifications call it a SuperSpeed USB connector (p. 1006). The USB Implementers Forum, the body that writes the USB standard, recommends that name for products that signal at 5 Gbps, five billion bits per second, and SuperSpeed USB 10Gbps for twice that. Nikon does not say it follows that naming, so 5 Gbps is an inference from the name, not a Nikon figure. A byte is eight bits, as Cards and Data Rates for Video explains, so

$$r_{\text{link}} \le \frac{5 \times 10^{9} \text{ bits/s}}{8 \text{ bits per byte}} = 625 \times 10^{6} \text{ bytes/s} = 625 \text{ MB/s}$$

and the copy through the camera takes at least $34{,}600 / 625 \approx 55$ seconds. A signalling rate is the speed of the wire, not of your files, so treat 55 seconds as a floor that a real copy will not beat.

The same arithmetic checks Lexar's published figures. A full 1 TB card at 900 MB/s takes $1{,}000{,}000 / 900 \approx 1{,}111$ seconds, about 18.5 minutes, against Lexar's "~18 min". At 3,600 MB/s it takes $1{,}000{,}000 / 3{,}600 \approx 278$ seconds, about 4.6 minutes, against Lexar's "Under 5 min". Both match card size divided by the rate Lexar quotes, so they are best cases in which nothing in the chain is slower than that rate.

An SD card gains nothing from the camera route, because its own 300 MB/s is already below the port's 625 MB/s, so it takes at least 115 seconds either way. The lesson of the table is that for the CFexpress card the camera's port, not the card, is the slowest link.

Now the drive. Suppose, only to show the effect, a backup drive that writes at 200 MB/s. That figure is an assumption for the arithmetic, not a measurement and not any product's rating. The second copy then takes $34{,}600 / 200 = 173$ seconds, nearly three minutes, longer than the first copy took through any reader. Both copies together take from $9.6 + 173 \approx 183$ seconds, about three minutes, with the fast reader, to $55 + 173 \approx 228$ seconds, about four minutes, through the camera. Over the whole routine the backup copy is the longest step, and a faster card would not shorten that step by a second.

06.FTP and Other Network Routes

The camera can also send pictures without the card leaving its slot. Sending to a phone was left to SnapBridge at the start of this chapter. Sending to a computer, over Wi-Fi or over Ethernet through a third-party USB-C to Ethernet adapter, needs Nikon's Wireless Transmitter Utility on the computer (pp. 34, 327, 341), and NX Studio and Tethered Shooting covers that link. The camera holds one kind of connection at a time, to a computer, an FTP server or a smart device, so one has to end before another can start (p. 327). That leaves FTP, which belongs here.

FTP, the File Transfer Protocol, is a long-standing way for one machine to send files to another that stores them, called the server. It suits a shoot where someone else is waiting for the pictures. The network menu item Connect to FTP server sends pictures to a server over Ethernet, through the same kind of adapter, or over Wi-Fi (pp. 322, 349, 365). On Wi-Fi the camera either joins an existing network through a router, called station mode, or makes a small network of its own that the server joins directly, called access point mode, which works where there is no router (p. 349). Nikon's support is narrow. It covers servers set up with standard FTP services, such as the IIS that comes with Windows 11 and Windows 10, and it excludes servers reached over the internet and servers running third-party software (p. 349). FTPS, the encrypted form, needs a root certificate, a file whose name must be ROOT.CER, ROOT.CRT or ROOT.PEM. The server's administrator can tell you how to obtain one. The camera imports it from the card and keeps only one at a time (pp. 349, 893).

With Auto upload at ON, each new photo is queued for the server once it is safely on the card. Without it, you mark pictures for upload in playback. Videos are never queued automatically and have to be marked in playback, and a video over 4 GB cannot be marked at all (pp. 247, 376, 891).

Five more options change how FTP upload behaves, and each one is OFF by default (p. 870).

• Overwrite if same name at OFF adds a number to a new file whose name is already on the server, rather than replacing the old one (p. 892).
• Protect if marked for upload protects each picture you mark and removes the protection as it uploads (p. 892).
• Upload marking stamps the picture on the card with the time it was uploaded (p. 892).
• Upload in HEIF format converts a raw or JPEG picture to HEIF at the compression you choose before sending it, and the HEIF is not kept on the card (p. 892).
• Keep connection tries again about 15 seconds after a connection error and keeps trying until it connects. While it is ON the standby timer never runs out, which costs battery (p. 893).

Protection on the card does not travel. The copies on the server are unprotected even when the originals are, and Nikon suggests ratings to carry your marks across (pp. 245, 378).

One more option deserves suspicion. Set to ON, Delete after upload erases each photo from the card once its upload finishes (p. 891). It is OFF by default, here and under Connect to computer (pp. 869-870, 886), and I leave it there. A finished upload is one copy on one machine, and deleting the card's copy at that moment removes the second copy before any backup exists.

Network transfer earns its place when pictures must leave the camera while the shoot is still going. Nikon publishes no transfer speeds for it, so the arithmetic above cannot price it, and for an evening offload of a full card I take the card out.

07.A Routine for the Evening

The routine rests on one rule. A card is formatted only when every file on it exists in two other places, on two different drives.

Start in the camera, before any cable. Culling there, as Playback and Culling in the Camera describes, means fewer files to move, and star ratings survive the trip, since NX Studio shows ratings set in the camera (p. 246). Protection is no safeguard at this stage, because a format wipes protected pictures too (p. 245).

Next, with the camera off and the access lamp dark, take the card out and copy all of it, every folder, into one new folder on the computer named with the date and the subject. Copying the whole card rather than choosing files means nothing is left behind by accident. After an Overflow day, look at the second card as well, because any frame shot after the first card filled exists only there. After a Backup day the SD card holds a duplicate of each picture, which makes it a third copy until the routine ends. After a RAW primary - JPEG secondary day, the SD card's JPEGs belong in the same folder as their raw files.

Then copy that folder to a second drive, one that is not the computer's own. Check both copies against the card: the same number of files and the same total size. A count is a weak check, but it catches a copy that stopped partway. Open a handful of frames from the backup, including the last one written.

Only then does the card go back in the camera to be formatted in its slot. If the next shoot comes before the second copy exists, shoot on a spare card and leave the full one untouched.

08.Recommended Settings

09.Beginner Mistakes

Formatting before the second copy exists. A format cannot be undone and takes protected pictures with it (pp. 245, 808).

Formatting on the computer. Nikon says not to (p. 45), and a card formatted as FAT32 cannot hold a file of 4 GB or more (p. 928).

Pulling the card while the lamp is lit. Turn the camera off and wait for the lamp first (pp. 45, 96).

Offloading one card after an Overflow day. The frames shot after the first card filled are only on the second.

Plugging the camera into a hub or a keyboard. Nikon asks for a port built into the computer (p. 326).

Tidying the card from the computer. A picture edited and saved on a computer can bring up "Cannot display this file." (p. 927). Edit the copies instead.

Turning on Delete after upload to save time. It removes the card's copy before a backup exists (pp. 886, 891).

Trusting protection on the server. FTP copies arrive unprotected, so carry your marks with ratings (p. 378).

10.Related Chapters

• First-Day Setup: inserting cards, and the quick and full formats.
• Card Slots and File Handling: Overflow and Backup, card speeds, and folder and file names.
• Playback and Culling in the Camera: ratings and protection before the copy.
• Cards and Data Rates for Video: bits, bytes and the card speeds video needs.
• Batteries and USB Power: keeping the battery charged through a long transfer.
• Heat, Power and Recording Limits: running the camera from USB power, and heat.
• SnapBridge, Nikon Imaging Cloud and the Authenticity Service: sending pictures to a phone.
• NX Studio and Tethered Shooting: the program behind Nikon Transfer 2, and sending pictures to a computer over Wi-Fi or Ethernet.
• Firmware and Updating: the one routine job where a computer writes to the card.
• Troubleshooting: card and connection error messages.