![]() ![]() Don’t throw it away.File size 57 KB vs Shrunk transparent PNGĮxcellent question! When you upload a PNG (Portable Network Graphics) file, similar colors in your image are combined. When you shoot RAW images your camera provides you with a tremendous amount of information. Maintaining a 16-bit workflow also gives you much greater latitude for making changes to tone and color. But our industry is changing rapidly and we are now seeing printers and monitors that take advantage of the information beyond 8-bits. John Paul Caponigro has said that “creating 16-bit files is largely about generating the best 8-bit data”. The file size is considerably larger but you have a much greater amount of data in these files. Essentially it gives you more slices of information within these ranges.Īs with many things with photography, the file bit-depth is a double edged sword. Nor does it extend the dynamic range of an image. They also point out that “making a conversion on a 16-bit image can often avoid problems such as banding in skies or posterization in shadows that suddenly appear after an 8-bit conversion.”įinally it should be pointed out that the greater bit-depth of a 16-bit file does not extend the color gamut of an image. Jeff Schewe and Bruce Fraser, in their book Real World Camera Raw, refer to this as “editing headroom”. By processing with 16-bit files, you maintain all the information necessary to ensure quality in all portions of the histogram. The more you adjust, the greater the risk of having gaps in your tonal range that become visible. Whenever you make any tonal adjustments you stretch or compress different parts of the histogram. If all you do is prepare images for the Web then 8-bits is plenty of information but you’ll want to process in 16-bits for just about any other scenario. If you convert the file to an 8-bit file, you’re throwing away a lot of that data. You shoot RAW to take advantage of all the additional data collected by camera. If my lab prints my images using 8-bit printers, why mess with 16-bit files? That’s a good question and not one that is intuitively obvious. These are converted to 16-bit files by programs like Lightroom, Adobe Camera Raw or the proprietary RAW file converters. The digital processor inside a DSLR will generate RAW file data in either 10-bit, 12-bits or 14-bits. If you instead shoot RAW files, the image data is saved in a format greater than 8-bits, although they are not all true 16-bit files. The JPG file format does not support 16-bit. If you shoot JPG images, they will be saved as 8-bit files. Any less than that and we would notice bands of different tones, a phenomenon called posterization. With 256 tones from black, to white, we perceive continuous tones. (You knew that math from school would come in handy.) The range of tonal values in an 8-bit image begin at black with all bits being “0”, all the way to white with all bits being “1” - 256 different shades from end to end. ![]() The total number of unique combinations for 8-bits is 256. Remember that each bit is either + or -, represented by either “0” or “1”. 8-bits of data are used to define the tone of each pixel in an image. Let’s take a black and white image first. For photographs we need to remember that images are made up from a collection of pixels. To produce the letter “A”, for example, the computer uses 8-bits of data. Deep inside your computer or camera that bit is really just a positive or negative electrical charge.įor normal data files, 8-bits are used to represent a single letter, number or symbol. And image files are simply data files that contain all the information necessary for your computer to generate an image. Yes, you have optics to focus the images but in it’s core your trusty Digital SLR is a powerful, albeit small, computer system. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |