
Eye-Fi does not officially support the use of their cards in SDHC->CompactFlash adapters, but I have not experienced any serious issues other than reduced range. One thing that can help is to remove the shielding from the adapter.
Insert something sharp, such as a protractor tip into the corner of the card where the metal meets the plastic, and simply pry the metal shield up. It is attached with a small amount of glue, that can be removed with a fingernail. Repeat for the other side of the card. Try not to cut yourself, the metal is razor sharp.. There is also a metal shield on the camera door, but I`ll have to find my set of tiny screwdrivers first to test that.

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Paul,
Great write-up about the CF adapters. But the problem is — reduced range is the least of your worries. The CF adapters cause file corruption, among other things. So not only do we not support them, we highly recommend against using them. Sorry
Hi Ziv! Can you provide more details? Is it all adapters in all cameras, or certain circumstances that cause problems, and how frequently? The main cameras of interest would be the Canon 5D/5D Mark II, and Nikon D300/D3. The D3 can be set to backup images to two cards at once, which should at least eliminate the chance of losing images if a problem does occur.
Hi Paul,
Yes, unfortunately, all adapters behave the same. Some are worse. They’re all using the same controller, and we’ve found corruption issues with Eye-Fi Cards and other cards. I understand that the D3 has 2 slots, but other cameras don’t. Canon pro DSLR’s have SD and CF slots, and the Pro card should be used in the SD slot. Even in older Canon gear that originally came out, only supporting SD, Canon released firmware upgrades to enable SDHC. I realize that Nikon DSLR’s in the pro range are all CF (I’m a huge Nikon fan)
I wish I had better news for you, but unless something changes on the adapter’s controller side, or until Eye-Fi will come out with a CF solution (no promises), CF is unsupported.
Hello,
What kind of DSLR have you ? i just bought an x2 with an adapter, trying to figure out how it works with my fuji s5 but it seems not to work
any clue ?
This particular wasn’t quite thoroughly clean.