Wi-Fi Memory cards are available for a good while now, with the predominant Eye-Fi brand, but until recently, their low capacity/performance could not justify the price.
In the 16GB/Class 10 category, the Transcend Wifi SD (TS32GWSDHC10) appears to be the cheapest on the market for 42€ shipping included.
Its SPI microchip supports Wi-Fi 802.11b/g/n including WEP/WPA/WPA2 encryption. The internal software can be upgraded. Mine arrived with v1.5 and the Transcend Android app advised me to apply the 1.6 update (released in March 2013) when it first made the connection.
The product pack does not include any CD but everything is available from the Transcend web page. The Firmware Update Tool runs from a PC and detects the card from any card reader.
The firmware update process is quite safe: I had a few failures first using the internal reader on my PC. Despite that, the card was never "bricked" and the 8-steps update, which took a good 15 minutes, eventually succeeded once I used a cheap USB card reader instead. The card was almost smoking hot after that, much more than during normal operation.
The card starts in Direct Share mode and acts as an Access Point to which mobile devices can directly connect using the Wi-Fi SD App.
It is also accessible from any computer thanks to its web server (default http://192.168.11.254).
Both interfaces allow to browse the content of the card and change its setup. Up to 3 Wi-Fi hotspots can be pre-defined for the card to connect to in Internet Mode, and the default startup mode (Direct/Internet) can be changed as well. The Wi-Fi SD app v1.8 tested has a Shoot and View feature which pushes any photo taken to the mobile device for viewing, handy for quality review on a bigger screen. Its Browse section gives access to local and remote files plus the option to share them
Update: The v1.9 came out while I was writting this review. It contains several simple but well thought improvements to the interface, like the indication of the IP Address used. The sharing destinations now extend to any available on the phone, so in my case Bluetooth, Gmail, Messaging, Picasa (at last!), and Send by LAN (ES File Explorer 3.0)
While it is recommended to turn off the camera power saving feature to maintain the SD card communication active, it is possible to set the card itself to turn off
the Wi-Fi after 1/5/10 mins. This is a welcome option as the card does not have a physical switch for this.
One thing to note is the absence of option to set a static IP address.
If you leave on travel with the card set to Internet Mode, it will be inaccessible if none of the pre-set hotspot are nearby. So it is advisable to always set your own phone as one of them.
There's however a smart and simple way to reset the SD card if needed, and thus get back to the Direct Share mode: Just delete the virtual, persistent "Restore Defaults" picture. The AP password will then revert to 12345678.
While the huge Canon Raw v2 (CR2) files are not seen as pictures by the app, they're listed in the category "Others" and can be transfered like any files. For the sake of reviewing the pictures taken, the camera should then always be set to JPEG+RAW rather than RAW only.
In general, the Transcend Wi-FI SD was good enough to convince me in getting a second card for my second camera. It definitely fills the bill for sharing pictures on the run and freeing up the camera storage space by offloading files to another device. However, because I'm curious, I decided to try a challenger for my next order.
Firmware update tool
Card reset can be done directly from the camera
Can transfer RAW(incl.CR2)/JPEG and any other file extension.
Generates somewhat more heat than the ezShare
--------------------------------------------------------------The second cheapest Wi-Fi SD is the ez Share 16GB from LZeal (ES100) at 47€.
The first difference is the presence of a physical switch to turn on the Share Mode, which I see as an advantage over Transcend.
Despite the LZeal product page, and the Q&A of the dedicated web site: "During share process, there is intermittent beep(every 30s) reminding Share Mode is on..." (at time of writing), there is no buzzer in the version I received. As suspected and confirmed by Lzeal, it is an old feature that has been removed from the latest products.
Another difference is the absence of an "Internet Mode", i.e. the card only acts as a hot-spot and won't blend in your existing Wi-Fi network. This becomes a disadvantage once you have more than one card like this, as you'd need to connect to each individually whereas the internet mode would allow to access all cards simultaneously.
This is a 16GB Class 10 memory with 802.11b/g/n capable module (Heng Bao chip) and while there's no word whatsoever on the encryption supported, it does WPA2 like the Transcend.
EZ Share Android app v.1.4.0 (also released while I was writing this review) is neat and simple. What Transcend Shoot and View feature is also present and simply called Auto-Push. EZ Share just uses the "Share to" targets of the phone, so there's no real limitation.
Browser access is done simply by going to http://ez
The web interface offers a classic and a mobile view with same features than the EzShare app. CR2 files could be displayed once transfered to my phone. Unlike the Transcend which now deals with all kinds of file types, the ES100 is limited to video and picture files.
To reset the card to its defaults, the dummy file ezshare.cfg (it doesn't hold any actual settings) must be deleted from a PC. I found that trick less neat than the Transcend virtual picture which allows the same operation directly from the camera. The AP password will then revert to 88888888.
The Wi-Fi range (Indoor only tested) is conform to the 10m specified and 65Mbps max speed.
The average transfer rates are: Read: 15~19MB/s and Write: 10MB/s,... not great for Class 10 (for which 10MB/s is the absolute minimum). It was however good enough to shoot 1920x1080 videos @ 24fps.
While it also meets my expectations, the ES100 does not offer the same value for the price due to its lower SDHC performance and fewer features. The physical Wi-Fi switch remains its main selling point.
Physical switch for the Wi-Fi mode
Only acts as a Hot-spot, no "Internet mode" (Router connection)
No "Wifi On" reminder (buzzer) on this version.
Write speed on the fringe for a Class 10
While difficult to quantify, the use of Wi-Fi function has an obvious impact on the battery, which is naturally more noticeable on the smaller SX220 than on the more powered EOS.
Trek FluCard Pro 16GB Class 6, ~70€
Eye-Fi Pro X2 16GB Class 10, ~100€
Toshiba Flash Air 8GB Class 10, ~50€