Fotografia digitala si tehnica, tot ce tine de tehnica facutului de poze si de prelucrarea pozelor dig Options

[kalua]

M-a inspirat Ariana si m-am apucat sa citesc despre cum se fac poze. (IMG:style_emoticons/default/smile.gif)

La carte scrie ca formatul raw este pentru o mult mai flexibila prelucrare a pozelor. Mie una nu-mi prea place sa le prelucrez, ori ies bine de la mama lor, ori le arunc. Trebuie sa-mi mai bat capul cu formatul asta?

[Master of Norule...]

A RAW file contains only the original, unprocessed picture data from your camera's image sensor. It's what the camera recorded without any modifications -- no fixed white balance, no sharpening, no contrast adjustment, no noise reduction. What's more, a RAW file is either uncompressed or only slightly squeezed with lossless compression, meaning that absolutely no actual picture information is thrown away. The RAW format also stores brightness data at 12 bits per color, just as the sensor recorded it, rather than JPEG's eight bits. That means it captures significantly more tonal information.

In essence, a RAW file is of intrinsically higher quality than a JPEG. It allows you to make major changes to an image after you've shot it and still retain good quality. And in working with RAW, you never modify the original file. But -- and this is a big but -- that file requires two to ten times more storage space than a JPEG.
The biggest advantage of RAW is that it gives you 12 bits of brightness data to work with, both in the RAW software itself and when you save the file to a 16-bit TIFF or PSD. Those 12 bits translate to 4,096 discrete levels of brightness -- 16 times the 256 levels available in a JPEG's limited eight-bit space. This is critical if you need to alter brightness in any significant way. The two darkest exposure zones in a 12-bit RAW file contain 384 levels of brightness; in the eight-bit JPEG, only 47 levels. If you decide to open up those shadows in a JPEG, you'll end up with abrupt jumps between the brightness levels. These appear as visible gaps in the histogram display. But an identical adjustment to the RAW file will cause no problems, because there are more than enough levels to ensure smooth transitions.



This post has been edited by misssn7: Mar 28 2008, 09:18 PM