All Digibird images were acquired using a Nikon Coolpix 990. The 990 generates 3 megapixel "raw" images; most images here were taken in 3:2 mode. Digibird uses a Leica APO Televid spotting scope as an afocal telephoto lens (more below). The archive "originals" are 2048x1360 pixel images--approximately 200 dpi resolution at 10x8 inches. At screen resolution, 72 dpi, that image is about 28x19 inches. For display in the Digibird galleries, the non-thumbnail images have been resized to about 527x324 pixels at 72 dpi.
The majority of "raw" camera files are JPEG compressed, by the camera, to approximately 1000 kb ("fine" quality). This is a compromise. Without compression, each raw file would require 10 Mb of camera memory. Aside from (considerably!) limiting the number of images that can be stored on the camera's memory, such large files result in very low frame rates through the camera. However, JPEG storage is lossy; some of the finest details may be lost in the compression process.
Even 1000 kb images are far too large for rapid viewing over dial-up connections. For Digibird galleries, the images have therefore been further compressed to about 50 kb. The thumbnails are extracted and compressed further, to about 5 kb. The cost of rapid thumbnail loading is the distortion visible in some images.
Finally, all images result from "digiscoping" or "eyepiece virtual projection", that is, fixing the camera at the eyepiece of a spotting scope (or binocular, in a few cases). Digibird's explanation of this technique is in this Primer; we suggest that you experiment with your own equipment. In short: find a bright, stationary, high-contrast subject; focus the scope on the subject; set the camera to maximum zoom; set the camera to auto focus and exposure; hold the camera lens as close to the eyepiece lens as possible; and start shooting!
