From Analog to Digital

One company’s shift in aerial mapping technology
By Bruce Bergman

While hardly news to large suppliers of aerial imagery, the digital revolution is finally completing its penetration into the market through medium and small photo suppliers. Film cameras are still prevalent and perform well for many projects, but, as more customers become comfortable with digital imagery, we see their preference shifting to digital acquisition for an increasing percentage of medium and even some small jobs.

Bergman Photographic Services, Inc. (BPS) has supplied aerial photography to mapping and resource customers for over 30 years. BPS started with military surplus gear and quickly upgraded to the Zeiss RMK with FMC and finally the latest generation of Zeiss TOP cameras, both 6” and 12” focal lengths, which continue to serve us well. For the last several years we have had requests from customers and opportunities to bid on projects that required direct digital acquisition. With our customer base comprised of regional mapping companies, local government contracts, and occasional subcontracts to other flight operators, we were unable to justify the cost of the first generation of digital mapping cameras.

However, our sales were declining, so we felt our future would be secure only with the digital option in place. Compounding our budgetary and customer needs was the announcement that Kodak Color Infrared film was being discontinued, making a digital solution a necessity in a world that is constantly moving away from analog products.

BPS decided on the UltraCam L, from Microsoft’s photogrammetry division Vexcel, as the tool to help us move into the digital world. We made this choice in part due to the fact that it covers 80% of the image area covered by the more expensive full-size UltraCam X, with an upgrade path to an Lp specification. While there are other quality digital solutions available, BPS felt the price-versus-footprint ratio worked best for us as a small operator unable to bear the cost of a new, full-size camera. Because the UltraCam line of cameras shares many components, regardless of low-end or high-end model, it allowed us to offer the same quality product to our client base with only the footprint changes.

Moving to digital offered us a secondary bonus: the self-contained nature of a digital camera allows computing and solid-state storage right in the camera cone. Only two of our aircraft are capable of carrying a large camera, while all four of our planes (including an aircraft as small as a Cessna 180) can carry the more compact model we chose. We also benefited from the ability to quickly and easily interchange the digital with our three Zeiss cameras and use the same camera mounts and flight management systems.

A first-time digital operator must also add appropriate computer processing and storage infrastructure, which can add up to a fair amount of work and expense. We found the workflow to be very different from our comfortable film systems. But “different” is the key word. After a year and a half, we think it is easier, more reliable, and certainly quicker to deliver digitally acquired imagery. We have had to get comfortable with not having a roll of film on the shelf, but with enough digital backups spread around we don’t feel vulnerable to a computer failure destroying our history.

One of the challenges we did not anticipate was struggling with our customers on how to spec our flights. It seems like everyone was born with the knowledge of what scale to use with a 6” camera to get a particular mapping accuracy. But when we tried to set a scale for the digital camera, the old formulas didn’t work, and there was a general distrust of the manufacturers’ claims for the vertical accuracy. Most of our customers had to use test flights over previously (film) mapped project areas at several scales to verify for themselves that base-height ratio for a film camera is not applicable to a modern digital camera and that digital imagery would indeed provide the accuracy they needed. This was enough of an issue for us and our customers that we petitioned Vexcel to make a series of webinars that explained the issues of converting a film workflow to a digital one.

Other areas we worked out with our customers are related to digital processing settings, frame numbering, and delivering and archiving images. Many of the questions that need to be settled in the processing area are the same that would be addressed in scanning of film. Those include choices in color balance, dodging (and hot spot removal), deliverables (color, CIR, 4 band), and of course various output formats and compressions.

After our first year and a half in the digital world, we believe the move to digital is a reliable solution. Our customers are very pleased with the imagery, and we see more projects being specified as digital that would have typically gone to film last year. Because the price point of the camera we chose allows us to quote digital projects very close to film prices, we see some jobs set up for either film or digital. The tools are very different, but the final output can often be used interchangeably.

We know the future will shift to digital technology, especially as the mapping-production software allows more automation to handle the higher number of images required to cover an area. Digital cameras are complex and still expensive even at the lowest-cost level, but the formula finally works for a small independent operator, smaller projects, and a lower use. Gone are the days when we could expect a camera to be useful for 15 plus years, but hopefully the savings in film, processing, and scanning will balance the perpetual cost to keep and upgrade digital technology.
Bruce Bergman is secretary-treasurer of Bergman Photographic Services, Inc., a precision mapping and oblique aerial photography service firm based in Portland, Oregon.

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