posted on Jun, 26 2008 @ 07:49 AM
While looking at Space Shuttle photos with Earth well lit in the background consider the lighting sources first. You would have to be on the same side
of the earth as the sun and in space it is bright, but in comparison, the earth is a huge second light source opposite of the sun in our perspective,
occupying half of our visible field of view, and is also very bright. Now also consider most of the Shuttle is white and reflective metal that is
reflecting from all over multiple subordinate light sources.
So yes, Shuttle photos look professionally studio lit with the correct camera exposure, I’m guessing a very fast exposure due to the light drenched
area and highly reflective, and white subjects. So dark backgrounds will also be exaggerated in the depth of it’s blackness, giving the whole
weightless scene a computer generated zero gravity look. Meaning wrinkles in materials looking uniform and fake without a nice gravity or wind blown
So we have a well lit stagnant near still life scene but here’s where the real problem comes into play. FOLKS, THESE IMAGES ARE SMALL, with high
detail. 1024 x 728 pixels is not even the resolution of an HD TV set, which is a small image for print reproduction that is even smaller than
continuous tone glossy photographs. They have been digitized with a very low pixel count. In print, the average pixel count I choose to reproduce on a
printing press for an image this size (approx. 10 X 7.5 inches) would be over 6,000 by more than 4,500 pixels, 6 times square the size of these jpeg
images. I prefer a 600 dot per inch (dpi) resolution for print, a continuous tone photographic negative has an effective count of over 2,400 dpi,
these jpegs are 100 dpi. For comparison the high-end 1080p cinematic computer animation movie image size is a 1920 X 1080 pixel frame size, still a
small image for printing.
What was that? A ‘jpeg’ image, –file extension - .jpg– (Joint Photographic Expert’s Group), is a commonly used method of COMPRESSION for
photographic images. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically
achieves 10 to 1 compression with little perceivable loss in image quality, but web color restrictions and loosy compression settings can noticeably
effect image quality for greater file size reductions.
Better digital picture choices for web viewing would be a tiff file format which uses NO compression compensation for storage space, or an eps which
requires even more file space than tiff files, and there are several more no-loss file formats, but we have all waited long periods of time on some
sites waiting for larger jpegs so that is the tradeoff. But God lives in the details, so the greater the pixel count, the better the image quality
that is preserved.
Digital image compression works in several ways, and an earmark visual clue would be color field averaging, which tends to look posterized, cutout, or
‘cartoony’, flat in effect. The compression would take an area of subtle color variations and apply a limited palette or even one solid color to
the entire area. The compression needs only to remember the code for one color applied to hundreds of pixels, less data to store. Interpolation occurs
in jpeg compression at sharp color transitions, ‘edges’ which tend to exaggerate the transition, ‘edge glow’ and also can create legacy pixels
after the transition, (pixilation), the additional spots of each color field in a percentage of intensity, due to poor edge anti aliasing, (smoothing
of the edges during pixel reduction, number of pixels), edge averaging, eliminating pixel, ‘stair stepping’ at diagonals and curves. Anti aliasing
tends to soften ‘blur’, what jpegs sharpen, or exaggerate.