Best Canon EOS 20D SD Memory Cards

´╗┐The Canon EOS 20D uses Compact Flash memory cards. 8GB is the max card memory size that is compatible.

A card over 8GB will not be recognized or cause the EOS 20D to display an error. Additionally, a Compact Flash card will need to be formatted in the camera or with the FAT32 file system.

Transcent 8GB CompactFlash Memory Card
Transcend 8GB CF card
  • Up to 50 MB/s Read; 20 MB/s write.
  • MLC NAND flash memory.
  • Supports up to Ultra DMA transfer mode 4.
  • Ideal for entry-level DSLRs.

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Amazon Adorama

Verbatim 4GB CF Memory Card
Verbatim 4GB CompactFlash card
  • High Performance controller for demanding applications.
  • Rugged - withstands up to 2000 g’s operating shock.
  • Low power consumption - Extends battery life.

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2GB CF Memory Card
2GB CF card
  • Up to 30MB/sec read/write speeds.
  • Operating shock rating of 2,000 Gs, equivalent to a 10-foot drop to the floor.
  • Low power consumption.
  • Minimum of 15 MB/second** sequential read speed.

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CF Memory cards come in two different sizes. The CF cards are referred to as Type I or Type II.

The only difference between the types of cards is how thick they are. The width and length of the cards are identical.

  • Type I - 3.3mm thick
  • Type II - 5mm thick

The Type II spec allowed for the use of Microdrives in the Canon EOS 20D. A Microdrive was a small mechanical harddrive.

When CF cards were first introduced they had high prices and limited capacities. Microdrives were the only solution to get large amounts of storage.

Microdrives are no longer being made. Because they were mechanical, failure was a matter of time. So you can’t find them used.

SD to Compact Flash card adapters also use Type II sized slots. The adapters allow you to use Micro SD or SD cards in a Compact Flash slot.

UGreen Memory Card Reader
UGreen Memory Card Reader

The UGREEN 4-in-1 card reader is what I use with my CF cards.

The UGREEN reader is USB 3.0 compatible. Using the card reader will provide transfer rates that are faster than what the Canon EOS 20D can do.

The reader supports these memory card types:

  • CompactFlash Cards
  • SD, SDHC, & SDXC Cards
  • Memory Stick (MS), MS Pro, MS PRO-HG, & MS XC DUO
  • MicroSD, Micro SDHC, & Micro SDXC Cards

One of the frequent errors with cameras that use CF cards are damaged card slot pins. If a pin is bent, you could see a ‘unable to use card’ error message.

To avoid bending pins, do not force a Compact Flash card into the Canon EOS 20D. The extra space for a Type II card allows a CF memory card to be aligned incorrectly.

If the CF card will not easily slide into the camera slot, take it out and check the positioning of the memory card. Also, check to see if the card is damaged.

If it looks fine, carefully position the compact flash card and try again.