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On the Sony α7 III (ILCE-7M3), format a card through MENU → Image (Setup) → [Format], then select the slot holding the card. Formatting permanently erases its contents, so copy anything you want to keep before you start.
Format the card in the camera
- Back up the card. Formatting erases all data on the selected card, including protected images and registered M1–M4 settings. Sony warns that this erasure is unrecoverable.
- Insert the card, then press MENU.
- Open Image (Setup) → [Format]. Use the control wheel to navigate and press its center button to select or confirm menu items.
- Select the memory-card slot that contains the card you intend to format, then confirm the on-screen prompt.
- Wait until formatting finishes. Do not remove the card while the access lamp is lit; formatting may take a few minutes depending on the card.
Sony’s ILCE-7M3 Help Guide gives the route as MENU → Image (Setup) → [Format] → desired memory card slot.
Check the slot before confirming
The α7 III has two card slots, and both accept SD cards, but their UHS support differs. Slot 1 supports UHS-I and UHS-II; Slot 2 supports UHS-I. Sony recommends Slot 1 when using a single SD card. Choose the slot that actually contains the card you want to erase.
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- The camera cannot format a card if the remaining battery charge is below 1%.
- Sony recommends formatting a card in the camera for first use. A card formatted on a computer may not be usable, depending on its format type.
- Formatting is not a data-recovery method. If files matter, copy them elsewhere before proceeding.
Choosing a replacement SD card
The α7 III supports SD, SDHC and SDXC cards for still images, but the required speed class depends on the recording mode. Sony’s compatibility table specifies Class 10 or U1 for certain HD modes, and U3 for XAVC S 4K 100 Mbps and HD 100 Mbps modes. Check the table for the exact recording mode you plan to use rather than assuming any SD card will support every video setting. Use Slot 1 for a UHS-II card.
#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.
See Sony’s official guidance for formatting, card slots, compatible memory cards and speed classes, menu navigation and registered M1–M4 settings.
Quick Recap
Best Value
- 225MB/s max read speed expedites transfers, and reduces wait times
- 160MB/s max write speed ensures you’re ready to get the shot
- Rated V30, it supports up to 4K 60FPS video recording to capture smooth, high-quality video
- Extensive compatibility with a variety of cameras and other devices, including Canon, Sony, Nikon, and more
- Built for durability – wearproof, drop-proof, temperature-proof, x-ray-proof, shockproof, magnetic-proof, and vibration-resistant
Rank #4
- Up to 100 MB/s data transfer speed
- Full- Sized SD card (32mm * 24mm)
- 4K Ultra HD UHD Video Compatible
- Waterproof, temperature-proof, x-ray-proof, and shock-proof, magnetic proof. With 1 mini case
- 5 year limited Warranty from best manufacturers and suppliers of memory cards
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
- 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.
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