[meteorite-list] Re: THE ART OF PHOTOGRAPHING Pictures 101
From: Martin H. <planetwhy_at_meteoritecentral.com>
Date: Sat May 21 16:30:12 2005 Message-ID: <20050521203010.83934.qmail_at_web40724.mail.yahoo.com> Hi Sterling and all, The 18 percent gray is more than trivia. The famous photographer John Shaw describes the light meter as actually a 'gray meter' and the implication are important. If you point a photographic light meter at snow in the sun, and take a picture, you will get an 18 percent gray picture. In order to make snow white, you have to over-expose the image in order to washout the white to actually make it white. With a digital camera, one can use the white balance adjustment to not only overcome issues of light temperature (ie. incandesent v. florescent etc.) but also adjust for a proper white in an exposure. But there might be an easier way depending upon your digital camera and that is with the scene selection options. The camera many have settings that compensate for backlighting, bright skys, bright foregrounds, night shoots, etc. If you have a light colored meteorite on a black background, it is similar to a light colored ballet dancer on a dark stage. Or if you have a darker specimen on as light background, it is similar to a skier on bright white snow. Simply setting playing with the scene selection choices and understanding how the camera is reading the light may make meteorite photography a whole lot easier. But it is also like using a GPS telescope. You can get great results, but you might not know how or why. Happy clicking. Martin--- "Sterling K. Webb" <kelly_at_bhil.com> wrote: > Hi, > > Before the first days of auto-exposure > calculation in cameras (film then), the > problem has always been to sum all the lights and > darks in a potentially infinite > range of images to determine a single correct > exposure. The original solution that > underlies auto-exposure and all the sophistication > of today's cameras is to assume > that if all areas of the proposed image were mixed > together like paint, the overall > outcome would be an 18% gray. > For decades, Kodak sold 18% gray cards and > sheets for photographers to > calibrate their exposures manually, even before > "auto" exposure. Even though they > may be using a $10,000 digital camera, most > (probably all) professional > photographers have yards and yards of 18% neutral > gray backdrop material. 18% gray > is the starting point for "correcting" exposure if > needed. It will produce the best > results, just like Anne said, for the reason that > the underlying algorithms of the > camera's electronics are build on that supposition. > > > Sterling K. Webb > ------------------------------------------------- > Impactika_at_aol.com wrote: > > > And I never use a black background, it just drowns > out the specimens. I > > found some file folders in a very soft, neutral > shade of gray and I find that it > > does not distort the color of whatever pieces you > put on it, being a green > > Tatahouine, a very dark Kainsaz or a yellow Libyan > glass. > > > ______________________________________________ > Meteorite-list mailing list > Meteorite-list_at_meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > Discover Yahoo! Get on-the-go sports scores, stock quotes, news and more. Check it out! http://discover.yahoo.com/mobile.html Received on Sat 21 May 2005 04:30:10 PM PDT |
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