One of the questions I’ve fielded often since the first edition of The iPad for Photographers is: How can I use an EyeFi card with a camera that takes only CF (Compact Flash) cards? All EyeFi cards are the smaller SD (Secure Digital) format, but some cameras—mostly professional bodies—use the larger CF size.
SD to CF adapters are available on Amazon and other outlets, but the reviews I’ve seen have always been spotty. Most adapters limit the range that the EyeFi’s Wi-Fi network creates.
Now, EyeFi has created its own adapter with a case made entirely of plastic to not blunt the Wi-Fi signal. EyeFi has more information and a list of supported cameras at its site: Eyefi certified CF Type II Adapter for Eyefi Mobi. The adapter costs $20.