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To format an SD card in the Sony α7 III (ILCE-7M3), press MENU, open Image (Setup) → [Format], choose the slot holding the card, and confirm. Formatting permanently erases the card, so copy anything you want to keep before you begin.
Format the card in the camera
- Back up any photos, videos, or other files you want to keep. Sony warns that formatting permanently erases all data and that the erasure is unrecoverable.
- Insert the card, then press MENU.
- Go to Image (Setup) → [Format]. Use the control wheel to navigate and press its center to select or confirm.
- Choose the memory-card slot containing the card you intend to format, then confirm using the on-screen controls.
- Wait for formatting to finish. Do not remove the card while the access lamp is lit.
Sony’s official ILCE-7M3 Help Guide: Format gives this menu route and warns that formatting may take a few minutes, depending on the card. The camera will not format a card if the remaining battery charge is below 1%.
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Check the slot before you confirm
The α7 III has two card slots, and the format screen asks you to select the card to act on. Slot 1 accepts SD cards and supports UHS-I and UHS-II. Slot 2 accepts SD cards with UHS-I support, as well as Memory Stick PRO Duo media. Sony recommends Slot 1 when you use only one SD card. See Sony’s instructions for inserting and removing a memory card.
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1Scan for outdated or missing drivers - takes under a minute2Repair Windows errors before they cause bigger problems3Fix the driver behind crashes, sound loss and screen glitchesWhat formatting erases—and what to do first
Sony states: “Note that formatting permanently erases all data on the memory card, and is unrecoverable.” That includes protected images and camera settings registered as M1 through M4 on a memory card. If you need any of them, preserve them before formatting; do not treat formatting as a recovery method. Sony explains the M1–M4 registrations in its Memory settings guide.
#1 Best Overall
- CAPTURE LARGER THAN LIFE. Unlock 4K UHD(3) brilliance and pristine high res stills with video speed class ratings of U3 and V30(4).
- SPEED BARRIERS SHATTERED. Save precious moments with blazing read speeds up to 250MB/s(2) and write speeds up to 170MB/s(2) [256GB-1TB capacities(1)].
- MAXIMIZE WITH MASSIVE CAPACITY. Capture for longer and store more with up to 2TB(1) of storage that can hold up to 2,808 minutes of 4K UHD video recorded at 30 fps (641MB/minute)(9).
- DEFY THE ELEMENTS. Unrelentingly resilient, Sandisk SD memory cards are engineered to perform in extreme conditions, despite rough handling and constant use.(6)
- CONTENT MANAGEMENT, SIMPLIFIED. Back up, organize, and transfer everything easily with the Sandisk Memory Zone desktop app,(7) whether you use an SD card slot or a card reader.
Use the camera to prepare a card for first use
Sony recommends formatting a card in the camera before first use. A card formatted on a computer may not be usable in the α7 III, depending on the format type. If the camera does not accept a card, check that it is compatible and follow Sony’s camera-specific instructions rather than assuming a computer format will work.
Choose a card for the recording mode
The α7 III supports SD, SDHC, and SDXC cards for still images, but the required speed class depends on the recording format. Sony specifies Class 10 or U1 for certain HD modes and U3 for XAVC S 4K at 100 Mbps and HD at 100 Mbps. UHS-II cards are supported in Slot 1, not Slot 2. Check Sony’s memory-card compatibility and speed-class table against the video mode you plan to use before choosing a card.
Quick Recap
Best Value
- CAPTURE LARGER THAN LIFE. Unlock 4K UHD(3) brilliance and pristine high res stills with video speed class ratings of U3 and V30(4).
- SPEED BARRIERS SHATTERED. Save precious moments with blazing read speeds up to 250MB/s(2) and write speeds up to 170MB/s(2) [256GB-1TB capacities(1)].
- MAXIMIZE WITH MASSIVE CAPACITY. Capture for longer and store more with up to 2TB(1) of storage that can hold up to 2,808 minutes of 4K UHD video recorded at 30 fps (641MB/minute)(9).
- DEFY THE ELEMENTS. Unrelentingly resilient, Sandisk SD memory cards are engineered to perform in extreme conditions, despite rough handling and constant use.(6)
- CONTENT MANAGEMENT, SIMPLIFIED. Back up, organize, and transfer everything easily with the Sandisk Memory Zone desktop app,(7) whether you use an SD card slot or a card reader.
Rank #4
- Save time with card offload speeds of up to 200MB/s powered by SanDisk QuickFlow Technology (Up to 200MB/s read speeds, engineered with proprietary technology to reach speeds beyond UHS-I 104MB/s, require compatible devices capable of reaching such speeds. Based on internal testing; performance may be lower depending upon host device, interface, usage conditions and other factors. 1MB=1,000,000 bytes. X = 150KB/sec. SanDisk QuickFlow Technology is only available for 64GB, 128GB, 256GB, 512GB and 1TB capacities. 1GB=1,000,000,000 bytes. 1TB=1,000,000,000,000 bytes. Actual user storage less.)
- Pair with the SanDisk Professional PRO-READER SD and microSD to achieve maximum speeds (sold separately)
- Shot speeds up to 90MB/s (Write speed up to 90MB/s. Based on internal testing; performance may be lower depending upon host device. 1MB=1,000,000 bytes. X = 150KB/sec.)
- Perfect for shooting 4K UHD video and sequential burst mode photography (Full HD (1920x1080) and 4K UHD (3840 x 2160) video support may vary based upon host device, file attributes and other factors. See HD page on SanDisk site.)
- UHS Speed Class 3 (U3) and Video Speed Class 30 (V30) (UHS Speed Class 3 designates a performance option designed to support 4K UHD video recording with enabled UHS host devices. UHS Video Speed Class 30 (V30), sustained video capture rate of 30MB/s, designates a performance option designed to support real-time video recording with UHS enabled host devices. See the SD Association’s official website.)
Rank #3
- CAPTURE LARGER THAN LIFE. Unlock 4K UHD(3) brilliance and pristine high res stills with video speed class ratings of U3 and V30(4).
- SPEED BARRIERS SHATTERED. Save precious moments with blazing read speeds up to 250MB/s(2) and write speeds up to 170MB/s(2) [256GB-1TB capacities(1)].
- MAXIMIZE WITH MASSIVE CAPACITY. Capture for longer and store more with up to 2TB(1) of storage that can hold up to 2,808 minutes of 4K UHD video recorded at 30 fps (641MB/minute)(9).
- DEFY THE ELEMENTS. Unrelentingly resilient, Sandisk SD memory cards are engineered to perform in extreme conditions, despite rough handling and constant use.(6)
- CONTENT MANAGEMENT, SIMPLIFIED. Back up, organize, and transfer everything easily with the Sandisk Memory Zone desktop app,(7) whether you use an SD card slot or a card reader.
Rank #2
- Speeds up to 280MB/s read, up to 120MB/s write
- Shoot stunning videos in 1080p Full-HD, and 4K
- Save time with a dramatically accelerated workflow
- Backwards-compatible at the highest UHS-I speeds
- Rigorously tested to ensure performance, quality, compatibility, and reliability
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