Architecture's digital revolution

By Ian Hardy BBC Click Online North America technology correspondent

Digital cameras are the technology miracle of the decade. Two photographers in New York State have taken this a step further, applying spy satellite technology to revolutionise architectural photography. Ian Hardy went to meet them.

Close up, 144 megapixels differs dramatically from 4 megapixels

At first they might not seem very different from any other photograph.

But take a closer look at the high-definition pictures created by Tom Watson and Rob Howard, and you will realise that the detail is incredible.

Captured using custom-made equipment, these photos can be blown up to billboard size and still look as good as a 10 by eight-inch print.

Tom Watson says: "This is a 144 megapixel camera. It writes a 140Mb file.

"If you compare that with the average consumer digital camera, it's about 100 times more data."

It takes a minivan full of technology. The large format camera is mounted on a sturdy, wind-resistant tripod. A laptop and 80Gb hard drive are also part of the kit.

The process is far from just being a quick click. It can take several minutes to capture each image, using a scanner attached to the back of the camera.

Each colour - red, green and blue - is scanned separately giving a vivid result. It is based on spy satellite technology.

It can take several minutes to capture each image

Rob Howard explains: "Some of our exposures can take as long as 18 minutes. Our shortest ones, in very bright daylight, we've got down to 45 seconds.

"But again, compared to a 1/500th of a second snapshot, that's a very different kind of parameter."

Building on techniques

They are not on the cutting edge of photography just for fun. They have revolutionised architectural photography.

A scanner moves across, capturing red, green and blue separately

For example, in the case of one bank building in need of a major facelift, every bit of damage had to be catalogued before a repair quote could be given.

"The way these buildings used to be surveyed was by two architects, one in a deckchair with binoculars, the other making a list of cracks," explains Tom.

"The one in the deckchair would call out each individual flaw in the building, and it would take two days to a week, and they'd have a list of repairs.

"We can now do it in one photograph."

No-one had to dangle off the top of the buildings to get a closer look either, as surveyors sometimes have to do.

Karen Winters, of King & King Architects, says: "Getting a high-resolution photograph, that you could zoom in on, look at the deterioration, detail what needed to be done to fix it, saved us significantly."

Not only were Tom and Rob able to produce an image that was detailed enough for professional inspections, they also had their camera lenses specially mounted to photograph buildings on a flat plane that allows architects to upload them on a computer screen and measure distances accurately.

The resulting images can help create line drawings in literally hours, instead of weeks

A traditional camera sees things differently, as Nicholas Lindabury, an architect at QPK Design, explains: "You have a parallax of perspective where you have the converging points to the vanishing point.

"Now, with the digital camera, we can actually correct that so that things can remain true and in scale."

The resulting images can help create line drawings in literally hours.

It used to take two people two weeks just to measure a building accurately and put it down on paper.

Designer's eye

Interior designers also now have a way of showing their progress to clients, without having to be on site in person.

The camera swings through the arc of a panoramic picture

Erin Sirianni, an interior designer at QPK Design, says: "The detail allows us to see exotic wood grains at a very long distance.

"It allows us to see carpet pattern that the eye would not normally pick up in regular photography."

Tom and Rob have also experimented with panoramic photography.

The usual digital method is to take multiple shots and stitch them together, but they have combined new and old technology to solve the problem.

Rob Howard says: "The way this system works is that there is a motor underneath the camera, and the whole camera swings through the arc of the picture.

"We're not sacrificing any of the quality, the high resolution is there, the true colours."

It is a system that has done away with many problems and created photographs of previously unseen clarity, but the way the image is made also limits its potential in certain circumstances.

In all of the photos there is no motion, and that is the major drawback because as the photograph is made over an extended period of time, anything caught moving inside the frame will automatically be distorted.

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