|Wireless photography with an iPad and ShutterSnitch - Continued|
ShutterSnitch FAQ: Selecting a wireless router|
Q: Do I need a wireless router?
Because several of the portable routers we've tested work so well, because they can help extend range and boost transmission speed when the distance between the camera transmitter and the iPad grows, and because they make it easier to integrate multiple camera transmitters, laptops, an iPad and more into one network,
it's our recommendation that you get one, even if you don't
Strictly speaking, however, the current Canon transmitters and the Nikon WT-4/WT-4A can create and connect to an ad hoc (peer-to-peer) network, so a router isn't required to establish a wireless link with the iPad and send pictures through to ShutterSnitch.
These transmitters will draw less power when there's a router in the mix, plus configuration of the transmitters and iPad is simpler since the router can also assign IP addresses to all devices, whereas in a Canon/Nikon-created ad hoc network each device's IP has to be manually entered. Connecting through a router means you can switch on strong WPA2 wireless security, vs the comparatively weak WEP that is the only security option with ad hoc linkups.
So, a router offers some real advantages. But you can get the job done without one, as long as you're using one of the camera maker's transmitters.
With any Eye-Fi card, a wireless router is required. Most Eye-Fi models don't support ad hoc networking at all, only infrastructure (ie router-based) networking, making a router a must. While the Eye-Fi Pro, both the classic 4GB and the current X2 8GB, are ad hoc capable, they can only join an ad hoc network, not create one. The same goes for the iPad and its Wi-Fi.
What's the significance of this last point? It means you have two wireless devices that can't get the ad hoc party started, and therefore can't connect to each other without the assistance of a third device, such as a laptop, that's capable of creating an ad hoc network.
Once either an Eye-Fi Pro card or the iPad has joined this network, the creating device can drop away; the Eye-Fi Pro and iPad can proceed from there. But the dependence on a third device to kickstart the ad hoc network means
we can't recommend an ad hoc connection between an Eye-Fi Pro card and the iPad. Please see the answer to this question for more.
Q: What should I look for in a wireless router?
You'll need to consider wireless protocol, frequency and features in making your buying decision.
Wireless protocol Nikon's WT-4/WT-4A, as well as Canon's three newest transmitters, support 802.11a/b/g wireless, but not the generally faster 802.11n protocol, so it isn't critical that your router support 802.11n if you intend to use just these transmitters. The same goes for classic Eye-Fi cards, which are 802.11b/g. That said, 802.11n routers that also support 802.11b/g are widely available, as are some that additionally support 802.11a.
The Eye-Fi X2 series are 802.11b/g/n, and in our testing transmit as much as 30-50% faster when operating in 802.11n mode, so a router capable of 802.11n is a good idea for this particular camera transmitter option.
Frequency Canon's and Nikon's transmitters as well as all Eye-Fi cards operate at 2.4GHz, which is the most common frequency band for Wi-Fi. Make sure your router is capable of operating at this frequency. Most do.
Any router that is frequency and protocol compatible with the camera transmitters will be similarly compatible with the iPad, since its Wi-Fi has all the bases covered: it supports 802.11a/b/g/n and both 2.4GHz or 5GHz operating frequencies.
Features If it's a router then you needn't worry about whether it incorporates the standard things you need like a DHCP server or wireless security - it will. There are two additional features, ones that are common but not necessarily universal, and we recommend that you try to purchase a router that offers them. These features are:
All four of the portable routers discussed next can save and load configurations. They all support DHCP Reservations too.
Save and load configurations If you need to do a full reset of the router you'll appreciate being able to get your settings back simply by loading a configuration file.
DHCP Reservations Sometimes called Static DHCP, Static Mapping or Fixed Mapping, DHCP Reservations combines the convenience of DHCP, where the router assigns the IP address to a connecting device so that you don't have the tedious chore of entering it manually, but ensures that a particular device is assigned the same IP address every time it associates with the router. That way, your iPad running ShutterSnitch or other destination device can always be found at the same network location. In turn, this means you don't have to check or change the destination FTP server address in your Canon or Nikon transmitter's menus each time out.
DHCP servers will usually assign the same IP address to a connecting device as they did last time. Usually, but not always (the reasons for this are too boring to go into). The key point is that DHCP Reservations will ensure that a device's IP address is not just usually the same, but
always the same.
As mentioned, this means the camera makers' transmitters will be able to find ShutterSnitch and its FTP server each and every time.
Eye-Fi cards use a probe-and-response method of tracking down ShutterSnitch, which means the configuration doesn't break when the destination iPad's IP address changes. So if the only two devices that will ever connect to the router will be your iPad running ShutterSnitch and an Eye-Fi card, a router with DHCP Reservations isn't mandatory.
But, it's possible at some point you'll want to have a computer join this network so that you can copy pictures from ShutterSnitch, and in that instance it will be more convenient if the iPad has been assigned the same IP address as every other time.
DHCP Reservations is a useful feature regardless of the camera transmitter you'll be using, so seek out a router that has it.
Q: That last answer was too geeky. Please just tell me, which wireless router should I get?
For use on AC power in a studio, practically any 802.11g/n wireless router you can buy today should work fine, including Apple's Airport Express and Airport Extreme plus various ones from Cisco/Linksys, D-Link and others. Keep in mind the considerations outlined in the previous answer and you should end up with an AC-powered router that will do what you need.
If you're considering one of Apple's wireless routers, note that you can't set them up using an iPad. This can only be done from a Mac or Windows computer using the Airport Utility application. Once configured they will work just fine, but if you need to make a settings change to an Airport Express or Airport Extreme, and you only have an iPad around, then you'll be stuck.
If you want to operate on location and off the grid, then a small portable router, preferably battery powered, is the way to go. We've tested several, ones that have a built-in battery or can draw current from a USB port and are therefore easily adapted for battery-powered use. The good news is that all but one passed muster; the others were portable wireless powerhouses.
Short Route: Left to right: The Aluratek CDM530AM, D-Link DWL-G730AP, D-Link DAP-1350 and Cradlepoint PHS300. Click to enlarge (Photo by Rob Galbraith/Little Guy Media)
We've settled on one. We'll explain which one and why towards the end of this answer. The four we've looked at are:
This 802.11b/g/n access point/router has both an Ethernet port (for connection to a wired network or direct to a broadband modem) and a USB port (for use with compatible 3G mobile data devices). It can be powered by the included, user-swappable Lithium Ion battery or AC using the included adapter (the battery gets charged when the unit is plugged in). It's configured through a web browser. The one we purchased is sold under the Aluratek brand name, but as the large letters on its front suggest, it comes from Zalip, a Taiwanese company that makes all manner of wireless routers.
Pros Don't let its ugly duckling appearance fool you, the CDM530AM is a great little router to put between a camera transmitter and an iPad. It's easy to configure, speed and range are a-ok, it runs relatively cool (this is a problem with some other routers when you want to run them in your backpack or other enclosed space) and battery life is excellent (we squeezed over three hours of near-constant transmitting from its 3.7v, 1800mAh battery and have seen over four hours when not transmitting quite as much).
The battery is readily replaced in the field and is a relatively common Fujifilm NP-120 type that can be had for less than US$10 from battery vendors on the web (we ordered from here and received batteries with a 2000mAh rating that work just fine in the CDM530AM).
It supports all the usual wireless security protocols and has all the usual router and access point features, plus the ability to get to the Internet through either a wired Ethernet link or a 3G mobile data device (it must connect through USB and also be compatible). It supports DHCP Reservations.
Cons Other than the puke-green exterior, the only downside we've identified is wireless speed. Not when carrying data from a camera to an iPad, then its speed is as fast as any other. That's because the router is capable of throughput that far exceeds the rate at which camera transmitters operate. But, if you're also hoping to use the CDM530AM as a wireless access point for a number of 802.11n-capable computers in your home or office, you'll find this router, which tops out at about 3.5-4MB/second in our testing, to be slow.
This router is similar in many ways, on paper at least, to the CDM530AM. It's an 802.11b/g router with a USB port for connection to compatible cell/mobile data devices. It can be powered by the included, user-swappable Lithium Ion battery, AC using the included adapter (the battery gets charged when the unit is plugged in) plus Tekkeon produces external batteries specifically for use with this and other Cradlepoints. It's configured through a web browser and has all the features needed for use with camera transmitters and an iPad, including DHCP Reservations.
Pros Cradlepoint supports a long list of USB mobile data devices, plus the company is quick to support popular new devices through firmware updates. It's also the only portable router we tested that can do WDS, a method of hopping a wireless signal between multiple PHS300s that allows for greater range. Oh, and the PHS300 isn't an icky green.
Cons With either the WFT-E2 II A or WT-4A, transmit rates through to the iPad and ShutterSnitch are as good with the PHS300 as with any router we've tried. But, this router trails the best of the other portable routers by 40% or so when the transmitter is an Eye-Fi X2. This is because the PHS300 doesn't support the faster 802.11n wireless protocol of the newest Eye-Fi series, whereas the CDM530AM and D-Link DAP-1350 (described next) both do.
Also, compared to its competitor from Aluratek, the Cradlepoint won't run for as long on its internal battery. Even with the PHS300's transmit power turned down to extend battery life we're able to consistently eek out 30+ minutes of additional runtime from the CDM530AM. The PHS300's battery compartment door can be tough to get slid open, while the user-swappable battery inside is fitted much too tightly to remove with your fingers alone. These factors can make changing the battery a multiple-minute affair. (A Google search reveals we're not the only ones who have struggled to get the battery out of a PHS300).
We're not done griping yet. The unit runs hot, uncomfortably so when operating from inside a camera bag for a couple of hours. It's also the only router of this group whose configuration had to be fiddled with specifically to allow the iPad to connect, and the necessary workarounds were only partly documented within Cradlepoint's support articles.
So, much to our surprise, the PHS300 is really no match for the CDM530AM overall. Consider the PHS300 only if broad USB cell/data device support is critical (it isn't for us) or if you plan to use two PHS300s with WDS to extend network range (though we'd more likely opt for a single, powerful non-portable router in this case).
This is an 802.11b/g/n swiss army knife of a device with separate access point, router and wireless client modes, each of which gets its own separate configuration. It has an Ethernet port for tying into a wired network or direct to a broadband modem and is powered by the included AC adapter (it has no internal battery).
The DAP-1350 can also draw power from any computer's standard 5V/500mA USB port, and a cable for this comes with it. This means it can also be powered from pretty much any external battery with a USB power output port, such as those from Tekkeon or even the paperback-sized no-name unit shown in the picture below.
Hours of Fun: A D-Link DAP-1350 wireless router powered from the USB port of a no-name Lithium Ion battery pack. Click to enlarge (Photo by Rob Galbraith/Little Guy Media)
The DAP-1350 is configured through a web browser, supports DHCP Reservations and has the requisite range of features and security provisions.
Pros This is the most versatile unit of this group, since it can be a full-fledged router, access point or even a wireless client. It has no speed advantage over the CDM530AM in a camera transmitter to iPad workflow; both this router and the Aluratek offer essentially identical throughput with either 802.11g transmitters or the Eye-Fi X2 operating over 802.11n. Range is also comparable.
We also tested the DAP-1350 configured as an access point and connected to a wired Ethernet network. Throughput was as fast as it could be for the configuration, and well over twice that of the CDM530AM in the same test. File transfers from a MacBook Pro 17 inch sent wirelessly to a DAP-1350 and onto the wired network measured consistently in the 9-10MB/second range, which means the DAP-1350's 10/100 Ethernet port was funneling data at or close to its maximum. This is impressive for a portable router.
Cons It lacks an internal battery.
This portable 802.11b/g router's core feature set is nearly identical to the DAP-1350 and it can be powered the same two ways. Other than the fact the latter model supports 802.11n as well, these are very similar products.
Except that the DWL-G730AP is slow. Slow, slow, slow. Comparing it to the DAP-1350, with both operating in 802.11g mode, the DAP-1350 is three to four times faster at transporting pictures to the iPad from a camera transmitter. The DAP-1350's range is also better. Our recommendation is simple: don't buy the DWL-G730AP, even if you see it marked down on a discount table at your local electronic store.
And the winner is...
The speed and versatility of the DAP-1350, as well as nice touches like its flip out stand, make it the best overall product of this little group. Alas, if only it had an internal battery. Because it doesn't it drops into second place behind the Aluratek CDM530AM for the task of transporting pictures from camera to iPad, since the two are equally fast at this and it's hard to beat the CDM530AM's self-contained simplicity.
We will keep the DAP-1350, though, since with a beefy external battery it can run for many, many hours. The thinking being there may be situations in which we need longer uptime than the CDM530AM's battery can give and we can't get to it to swap in a fresh battery.
The winner is the Aluratek CDM530AM. Team it up with a couple of spare NP-120 batteries and you have a wireless router that will run all day on location, reliably delivering photos to the iPad and ShutterSnitch at up to moderate distances.
Geared Up: An iPad and CDM530AM, on location. Click to
enlarge (Photo by Rob Galbraith/Little Guy Media)
Note: There are other portable routers out there that may also work just fine. The only other model we considered - and rejected - was the Trendnet TEW-654TR, and then only because it doesn't support DHCP Reservations. It's otherwise very similar in features and specs to the DAP-1350, though because we haven't tested the Trendnet unit we can't say if it's as fast or works as well the D-Link.
Q: Does a portable router, such as the Aluratek CDM530AM, have enough power to transmit wireless signals to an iPad as far 100ft/30.5m - 200ft/61m away?
No, or at least not faster than a snail. At the start of this page we identified four different things that we want a ShutterSnitch wireless workflow to do. Three don't need heaps of wireless range and are well-served by a portable router. The fourth, remote camera monitoring, can require the wireless signal to travel much further. For example, if the camera is behind the soccer goal at one end, and you're on the sidelines close to the other end, there's no chance that a router like the Aluratek CDM530AM will be able to effectively bridge that distance, whether you put it near the camera, near the iPad, or somewhere in between.
Just arrived here is a Ubiquiti Networks PicoStation M2-HP (shown at right), an 802.11b/g/n wireless access point, router and client whose transmit power is far higher than any portable router or most desktop routers and is designed to carry wireless signals greater distances than typical consumer products. Positioned closer to the camera transmitter, it should be able to fling pictures to a distant iPad and do so quickly.
Or that's the hope, since we're counting on the PicoStation M2-HP to handle outdoor remotes that may be 100ft/30.5m - 200ft/61m or more away. We've only just begun testing, but so far it appears to have incredible range, excellent signal-receiving sensitivity and more than enough speediness for the camera transmitters, but lacks support for DHCP Reservations.
We'll update this article once we've completed testing and a couple of real world trials of the PicoStation M2-HP.
Transmitter options are discussed on the next page.