What do you get if you combine WiFi technology with SD card storage? You get a wireless SD card, obviously. But what benefit does that actually offer, and if you're in the market for one then what should you be looking out for?

What is a Wireless SD Card?

If the name doesn't give it away, a wireless SD card is an SD card with WiFi networking technology built-in. The storage capacity of SD capacity has gradually increased while the memory chips themselves have shrunk - leaving room in the plastic housing for additional chips - like a WiFi chip. The SD card broadcasts its own network to which mobile devices and WiFi-equipped computer can connect.

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Capacity, or a MicroSD Slot

The biggest brands in WiFi-enabled SD cards come in specific set capacities - 8, 16 or 32 gigabytes - but there are cards come without internal storage of their own, requiring that you add your own microSD card. Clearly, if you've already invested in a large capacity microSD card that you'd like to use wirelessly, this might be a good choice for you. However, bear in mind that you may not get as many features or the best performance from a device that isn't fully integrated. Particularly, taking burst mode photos or HD video will require an MicroSDHC class 10 card.

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Connectivity and Range

Look for 802.11n transfer speeds - older cards will only be able to transfer at slower b or g speeds which may not be able to keep up with your shooting. Range may also be important for you depending on the target environment. Clearly, if you have an assistant within ten feet of you who'll be holding the iPad, it won't matter so much, but if you're tethered to a laptop inside a building and need to shoot outside wedding photos, it becomes an issue. The best wireless SD cards can theoretical transmit at a maximum distance of 100 feet without obstacles.

Wireless Transfer

The most basic feature offered by a WiFi SD card is the ability to transfer files wirelessly, avoiding the need to remove the card, plug it into an SD reader on your computer or laptop, import the files, then safely eject it and slot it back in the camera. How tiresome! With a wireless SD card, all you need to do is connect through the supplied transfer utility and avoid the fuss. The cheapest cards will only provide a web interface which you may find clunky for extensive use. Better cards will offer companion mobile applications which simplify the process; the best cards will provide a desktop application too.

Automatic Upload

The main purpose of having a storage card or multiple cards is to keep your photos and videos until such a time as you're able to move them into your archive or post-production environment, but that paradigm doesn't really make sense if you're at home or on a location with an immediate Internet connection available - you might as well have them automatically upload in the background while you continue shooting.

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Some cards also allow immediate and automatic sharing to social media sites, or at least integration with a variety of cloud storages. So even if you don't have a laptop handy to shift files onto, some WiFi SD cards will be able to upload the content to a Dropbox account. Your remote office or client can preview your work before the day is done!

Shoot and View Mode

Similar to automatic upload, "shoot and view mode" - a feature found on Transcend wireless SD cards but may be called something else for other manufacturers - allows you to use a tablet or smartphone app to immediately preview the photos as they're taken, parallelising the post-production process to enable a smarter and faster workflow.

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Additional Camera Features for EyeFi Cards

Wifi SD cards are compatible with any camera that uses an SD card, as the card itself handles WiFi capabilities. However, as the market leader, EyeFi has worked with camera manufacturers to enable additional features. You can find a list of cameras with added features here. This video explains the selective automatic upload feature in action on a Canon Rebel T4i:

Price Range

Prices vary from around $30 for a "bring your own MicroSD card" generic variety to $100 for a 16GB Pro X2 EyeFi wireless SD card.

Do you currently have a WiFi SD card, and are you happy with it? I'll let you in on a little secret: we're reviewing a few wireless SD cards next month, so stick around and we'll tell you exactly which is best - and let you win one.

Image Credits: K?rlis Dambr?ns Via Flickr