Introduction 
Rear view of the Nikon WT-2A wireless transmitter.
The Nikon WT-2/2A was released alongside the
D2X Digital SLR in February 2005 and uses
IEEE 802.11g to automatically upload images to an
FTP server as soon as images are shot. In addition to
FTP support, it also adds support for the
PTP/IP protocol to provide remote control capabilities.
When coupled with an
FTP server such as Pixagent's
ITP, the WT-2/2A will move images to a computer so that they can be processed/displayed in parallel with their shooting. This allows the photographer and their clients immediate access to their photographs in order to maximize the speed of their workflow.
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PTP/IP Support
One of the major new features added by the WT-2/2A is support for the new
PTP/IP protocol. When used in this mode, the camera will behave as if it were teathered to the computer via a USB cable. As such, users can remotely control the camera (fire the shutter, change settings, etc.) over a wireless network. It will also automatically retreive images from the camera, although the user does lose some granularity over the way they are sent.
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Configuration
The WT-2/2A can be configured in one of three basic manners - via
configuration files, a new wizard interface or by manually entering the settings. When using
configuration files to set up the camera, the settings are entered on a computer (either via Nikon's configurator or
ITP's configuration subsystems) and saved to a memory card where the camera can load them. These files are backwardly compatible with the
WT-1 so any software that can handle the older transmitter will work with the new one.
When using the wizard interface, the camera will walk the user through the process of setting up the camera while testing each value as it is entered. This system makes the setup process much easier than simply entering the settings manually as problems can be spotted immediately.
Once all of the settings are entered correctly, then the transmitter will connect to the server and begin sending images. If there are any errors, the three LEDs on the back of the transmitter will provide feedback (see
this link to help diagnose any problems). Note that the WT-1/1A is very sensitive to errors, so it is important for users to carefully enter their settings.
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Wireless Settings
These parameters control what wireless network the camera will connect to. All of the devices that are to communicate must have these settings in common, so it is important that they are entered in exactly the same manner on both the camera and laptop.
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Network Name/SSID
This is the unique name of your wireless network and, as such, is used by the camera to figure out what network it should connect to when it starts up. When used on an existing network, the SSID from that network should be dialed into this field. When creating a new ad-hoc network, the user simply has to make sure that the name entered here matches the name entered in the laptop.
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Network Type
The
802.11g standard allows two basic modes of opperation -
ad-hoc and
infrastructure. In the former, wireless devices (such as the WT-2/2A and your laptop) communicate directly with one another. Using this mode, the transmitter and your laptop are the only pieces of equipment necessary in order to transfer images. Unfortunately, when in this mode the camera will revert to
802.11b speeds so transfer rates will be significantly reduced.
In the later, all wireless devices communicate through a central arbiter called an
access point. This device controls all communication over the network, so
infrastructure networks are typically more robust and stable than
ad-hoc configurations. Further, since
infrastructure networks will function at full
802.11g speeds images will be transferred about 4x faster than when in
ad-hoc mode. The downside, however, is that this is another piece of equipment that photographers will need to carry around so it can add complexity to field setups.
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Channel
Only active when the camera is used in its
ad-hoc mode, this field allows you to select the frequency that the network will opperate on. Note that
802.11b/
802.11g channels overlap so you should make sure that you are at least five channels away from any other wireless networks (using channels 1,6 and 11 are ideal).
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Encryption
These settings allow you to configure your network to encrypt all data passing over them. These settings must be identical on all devices involved in the network or they will be unable to communicate. When enabled it will make it more difficult for people to intercept the images being sent from the camera. Note that using this option will slow down the rate at which images are being transferred.
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TCP/IP Settings
These settings determine the network setup that the camera will use once it is connected to the wireless network. Note that it is important to get these settings right, as if any of them are out of place the WT-2/2A will fail to connect to the server.
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Use DHCP
When this is enabled, the camera will automatically retreive the network settings from the
DHCP server on the network (typically inside of the
router). This is the easiest way to set things up, as the remainder of these settings will be handled automatically - however it is dependant on the server being present. On
infrastructure networks there will almost always be a
DHCP server present, however with
ad-hoc networks users will typically have to enter settings manually (the exception being users of
ITP 2.0 as it contains a built-in DHCP server).
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IP Address
The
IP Address that the camera will use when connected to the network. This number is basically acts like a phone number on the network - it is used by other devices to communicate with the camera, so it is important that it be set correctly. In most configurations, the first three numbers of the IP Address must be the same as the
FTP server however the last must be unique (eg if the laptop was using the address 192.168.0.100, then an address like 192.168.0.50 would be suitable for the camera).
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Subnet Mask
This field is used to help determine which devices are located on the local network and when it will have to go out to the Internet to complete a request. For most personal configurations, it is best to leave this set at 255.255.255.0. Further discussion of the
subnet mask is beyond the scope of this article.
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Gateway
The
gateway is the address of the
router used by the local network to communicate with the outside world. If the camera and laptop are connecting over the same network, this can be left disabled as the camera has no need to go out to the Internet. When necessary, this value can generally be found in the network setup of other computers on the network.
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DNS DNS (Domain Name System) servers are computers that help translate domain names (such as
http://www.photographicworkflow.com) into their respective IP Addresses. As above, this is only necessary when you are attempting to connect to a server over the Internet so it is generally fine to leave this disabled.
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FTP Settings
These settings are used to guide the camera into where the images will be sent and how to go about it. As such, they are critical to proper opperation of the transmitter.
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Server Name
This field is used to specify the location where the WT-2/2A will connect to in order to upload files. For conventional setups, this should be set to the
IP Address of the laptop that you would like to send the images to. Note that this computer must be running a
FTP server such as
ITP so that it will understand the commands coming from the camera.
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Path
The location where the camera will try to upload the files. Note that this path is
relative to where the FTP server is configured to save the images, so users cannot provide absolute paths at this location. As such, it is generally best for users to leave this field blank and handle this task with on the server side.
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FTP Username/Password
These are the credentials used by the camera to identify it to the FTP server. An account should already be present on the
FTP server and those credentials should be entered here in exactly the same manner as on the server. If the server allows anonymous logins, then the generic username 'anonymous' can be used with any password.
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Other Settings
The remaining settings (proxy, port and passive mode) are advanced values and should be left as-is unless users have specific instructions to change them. They are used on more complex network setups and are generally not necessary for small network configurations.
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RF Characteristics
Using information filed with the FCC durring the licensure process, the following tables provide basic information about the RF characteristics of the Nikon WT-2A. Note that these tests were performed on the North American
WT-2A variant and may be different than the WT-2 sold in other areas of the world.
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Basic Information | FCC ID | CGJWT02 |
|---|
| Frequency Range (WT-2A) | 2401MHz-2474MHz |
|---|
| Frequency Range (WT-2) | 2401MHz-2522MHz |
|---|
| Adapter Type | uPCI (Toko TMW1073) |
|---|
| Stock EIRP | 9.57-10.39dBm |
|---|
| Antenna Type | Modified RP-SMA |
|---|
Source: FCC/Testing
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Transmit Power | Frequency | Power |
|---|
| 2412MHz (Ch. 1) | 11.07dBm (12.79mW) |
|---|
| 2437MHz (Ch. 6) | 11.81dBm (15.17mW) |
|---|
| 2462MHz (Ch. 11) | 11.89dBm (12.91mW) |
|---|
Source: FCC
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Antenna Gain | Antenna | Gain |
|---|
| Stock (WA-S1) | -1.5dBi |
|---|
| Optional (WA-E1) | 4dBi |
|---|
Source: Nikon Specifications
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Design 
Overall design of the Nikon WT-2A wireless transmitter.
The WT-2/2A is form fitted to the base of the D2-series
DSLRs and draws power from a port on the bottom grip of the camera. It communicates via an external USB 2.0 cable teathering it to the data port on the camera. Three LEDs on the rear-right of the unit provide basic information about it's opperation, but most of the controls are performed via menus within the camera.
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Compatibility
The WT-2/2A is supported by the Nikon
D2Hs and
D2X DSLRs. Unfortunately it will not function with the older
D2H as it requires additional firmware that is not present in that camera.
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Variants
The WT-2/2A was sold as two basic variants, the Nikon WT-2 and the WT-2A. The later was only sold in North American markets and only had access to channels 1 through 11 of the
2.4GHz WiFi band to comply with local regulations. The former variant was sold in other markets and covered all 13 available channels in the
2.4GHz WiFi band. Other than that, the two transmitters are identical in both functionality and form.
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See Also[
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External Links 
Linear Mode
