“You’re just not going to get access to the whole range of the scene,” said John Peterson, a senior computer scientist at Adobe who helped develop Photoshop.

The problem, quite simply, is that the data image editors need is not captured by cameras, even if the image was saved as a RAW file, which holds more data than a conventional JPEG photo.

The concept of H.D.R. photography is fairly simple. It starts with a photographer harvesting every bit of difference in brightness by taking several different photos of the same scene, with large exposure differences between them. Software then sorts through the resulting images, which range from underexposed views that are nearly black to washed-out overexposures, to calculate the full dynamic range of the view. Using that vast amount of data, it then constructs a single, high dynamic range photo.

At least that’s the theory. While the actual practice can be highly automated, it is slightly more complicated.

While Adobe did not invent the idea of H.D.R., it popularized it by making it a feature in Photoshop CS2, the $650 professional version of its program introduced last year. (H.D.R. is not part of Photoshop Elements, the considerably less expensive consumer version of the program.)

Mr. Dejesus uses PhotomatixPro, which is available for $100 from a French company, HDR Software (www.hdrsoft.com). And a German programmer, who prefers to call the process full dynamic range photography, sells a program called FDRTools for $53 (www.fdrtools.com).