Behind Live Stills

Live Stills is a technique that grew out of my work with Shahar – introducing photography into the settings of a live performance. Technically it enables me to transmit still-images from my camera to a computer (using a wireless network) from which they can be projected. Artistically this has enabled me to partake in performances, working on stage with the performers while images are projected directly into the space.

PLEASE NOTE:

• This article covers numerous technical issues. It is based on my experimentations and my limited technical expertise.
• To this day I am using the same software and hardware that I originally used 3 years ago. This is a technological lifetime – most of the technologies have been replaced by newer, and usually improved technologies.
• It took me much trial and error to create a stable work configuration.
• I was working on a very limited budget so I did not try different kinds of equipment which may have yielded different/better results.
• If you are setting up your environment I suggest you take time to experiment and play around until you find a configuration that is accessible and relevant for your work.

Camera

The camera I use is the Nikon D200. The main benefits of the camera were, for it’s time, the high ISO performance and fast auto-focus. I shoot in photographically challenging conditions – people moving unexpectedly in shifting light conditions ranging from low light to extremely high contrast.

Wireless Transmitter

Attached to the camera is a WT-3 wireless transmitter. This is a custom unit that works only with the Nikon D200. Essentially this acts as a “Wireless Adapter” to the camera – making it possible to connect the camera to a standard wireless network. The wireless transmitter provided me a hard earned (see below) freedom to move while staying connected to a computer without any cables. It enables file transfer using either a proprietary Nikon software PTP (peer to peer) protocol or via FTP. Though I’ve never tried it, there is also a standard network cable connection port. There is also an option to control the camera remotely using a separately sold software package Camera Control Pro from Nikon.

Computer

I used a Windows XP based laptop computer with wireless connectivity to receive and present images.

Network Connectivity

Most wireless networks are based on a wireless router. All the wireless devices that are configures to connect with a wireless router can communicate through it. All communication go through the wireless router – there is no direct communication between any two devices. For some time, in the beginning of my exploration, I used this kind of configuration. My gear included a wireless router that I would activate in the space where I would be working. Both the camera and the computer were configured to connect to the router.

Another kind of wireless network is an ad-hoc network. In this configuration the devices are connected directly to one another. Eventually I stopped using the router and switched to working with an ad-hoc connection directly between the laptop and the camera.

I originally chose to work with a wireless router in the hope that it would give me better transmission range (better coverage of a space), which I believe that it did. But for some reason (I could not figure out why), on too many occasions, the Nikon connectivity software on the laptop could not link to the camera. Indicators on the camera showed that the camera was connected to the network, but also that it wasn’t able to link to the Nikon communications application on the computer. This is why I gave up on working with a router and switched to the ad-hoc configuration.You will need to consult the documentation of your gear to see what is available for you and how to configure it.

Network Range

The camera’s wireless adapter had a very limited range – if I moved too far from either the router or laptop computer I would lose a connection.Range is also affected by the space itself. Range will be best in an open space with a clean direct line of sight between the transmitter and the receiver. Range is reduced by the presence of both physical objects (walls!) and/or people in the space.

There seem to be many solutions for improving network range. The problem was/is that there isn’t reliable information on how well they actually work. So it requires trial and error – which a limited budget doesn’t really allow. After all of my researching I decided to try an antenna. When I was working with the router the antenna was attached to it (for which it was originally designed). When I was working with an ad-hoc connection the antenna was connected to the camera.

The camera’s wireless transmitter has a screw-in socket for an antenna connection on the side of the body. Nikon sells a ridiculously expensive antenna – it’s price and the complete lack of reliable performance information or a testimonial by someone else who had worked with it, prevented me from trying it. I was concerned that other antennas may not even have a compatible physical connection. Luckily it seems that the physical connection port is a standard size and I was able to connect the antenna directly to it.

I was fortunate to find an antenna that (unlike the Nikon antenna) has a joint in it’s base, that enables it to bend into a 90 degree angle (like this). This meant that I didn’t need to move around with a long stick coming out of the camera – I could fold it at the joint and place it alongside the camera body. If you do get an antenna, try to get one that won’t get in your way. There are accessories such as extension cables and connectors you can use to try and create a configuration that is comfortable for you.

Wireless networks have come a long way over recent years. There are newer protocols that offer longer range and better connections. If you are using newer equipment you may find that you don’t have a range problem. You have to play around and experiment with the gear you have to see what works for you and what limitations you need to accommodate in your work.

Stability of Connection

Another problem was that the network connection was unstable – the camera would lose it’s connection to the network and then take too long or have a hard time (or completely fail!) reconnecting. This has nothing to do with the range or the network configuration you are using. This was one of the most difficult problems to solve. It was the last piece of the puzzle – and it wasn’t documented anywhere. It is a classic case of engineer thinking!

IMPORTANT: I experienced the following behavior on the Nikon D200  & WT-3. I don’t how other Nikon cameras, or other manufacturer’s cameras. This was a huge problem for me so I thought it would be useful to document it.

Wireless camera connection was a relatively new technology when I began playing around with it. It seems to me that the Nikon engineers who created it had no actual use for it, otherwise it would be hard to explain how they chose that a flashing RED light indicates that the network connection is good. It seems that one of the design goals that the engineers had in mind was saving battery power so that batteries would last longer.

For example – when you half-press down the shutter button, the camera activates a light meter (and if active, the auto-focus system). If you release the button the meter stays active for a few seconds, this gives you a chance to read the light meter if you want to, but then it shuts off to save power (active light meter and auto-focus systems drain the batteries). On the D200 you can set this duration, the shortest setting is 4 seconds. So far so good, to me this makes sense.

Here’s where things begin to make less sense. When the light-meter system is shut down (the camera is assuming you don’t intend to take a picture) the wireless transmitter is also shut down (since is isn’t likely there will be any pictures to transmit). This does save power but it kills the wireless connection. The light-meter comes in instantly when you press the shutter button, but it takes many long seconds to reconnect to the wireless network. I needed to create a stable and continuous wireless connection. The way to do this was to set the light-meter shutdown delay to infinity – which essentially means that it never shuts down, and neither does the wireless transmitter.

Presentation

The last piece in this puzzle was the software for presenting the images that were transmitted to the computer. The images were placed in a folder on the receiving computer’s hard drive (there is a configuration option in the Nikon software to choose the target folder). The question was how to present them?

Before I describe my solution, I think it’s important to point out that this is an artistic junction – there are endless possibilities here, and before you choose and limit yourself to a specific technical solution, you may want to make some artistic choices. My intentions were to work within a live performance. I would most likely be away from the computer so there was not much likelihood of interaction with the computer. I also wanted to be free to work in the space – so I wanted as little distractions as possible (praying for a stable network connection was enough distraction).

I wanted a very simple behavior. I wanted the screen to display the most recent image shot and transmitted to the computer (usually I would auto-transmit all of the images, sometimes I would select which images to transmit, this is a configuration option on the Nikon wireless transmitter that can be changed through the camera menus). I wanted the image to be displayed in full screen and properly oriented (vertical shots needed to be rotated 90 degrees). I searched and searched and could not find an application that did just this. Most of the applications I found had slide-show features which looped through a set of images. I didn’t want the images to loop – I wanted the last image shot to stay on screen.

I was rescued by Yaniv who kindly agreed to write a custom application for me (runs on Windows XP). The application does exactly what I had hoped for – it is placed in the folder in which images are stored and it watches that folder for new images. The newest image is displayed correctly oriented in full screen. There is also an option to freeze the application by pressing space – so that the displayed image is not changed even if new images are found. Pressing space a second time releases the application and the newest images is again displayed (any images that were taken while the application was frozen will not be displayed).

There are many fine points you need to take care of. For example: the application needs to stay-on-top of all other application (if, for some reason, a network connection is lost, the Nikon wireless software opens a new explorer window showing the content of the folder in which images are stored); screen savers need to be disabled; the windows task-bar should be hidden. Still after all of this the solution is not technically perfect and there are many more creative directions I look forward to exploring when the opportunity presents itself.