Archived posting to the Leica Users Group, 2006/02/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Marc James Small wrote: > At 06:43 PM 2/6/06 -0500, Tina Manley wrote: > >> You don't really need a RIP. You can print directly with the >> profiles provided by Epson and get pretty good results. If you want >> wonderful results, you will go with a free profile available on the >> internet. There are profiles for every paper and ink >> combination. Just Google them. When you think of how many >> combinations that is, you can understand why they are not all >> provided with the printer. > > You still have not defined what an "RIP" is -- Raw Induced Psychosis? > Really Insipid Pseudo? Rascals In Psoriasis? What does it MEAN? > > And the rest of your scribe is even more frightening. What is a > "profile"? > and what, then, is a "free profile"? > > Give me chemistry. That I undersand. Hah. Digital imaging probably isn't more complicated than chemistry ... it just has its own domain of knowledge. Regarding a RIP --- back in the old days screens and printers were divided into two types: vector devices which draw lines (e.g. an oscilloscope) and raster devices for which pictures are made of a stack of generally horizontal lines of varying intensity ... the television is the archetype. see: http://en.wikipedia.org/wiki/ Raster_graphics and http://cjs.cadmus.com/da/glossary.asp - a "RIP" is a "Raster Image Processor" which is essentially just a fancy driver for a printer, or a fancy program which controls a printer or group of printers. You can forget about RIPs for the moment -- you'll know when you might need one, but that is only after you learn a bit more than the basics of printing. A "profile" on the other hand is an important concept to understand. Basically different films, monitors, scanners, printers, inks and papers have slight differences in how they respond to and render colors. A "profile" is a method to quantitate this. A profile is directly analogous to the "Zone system" for digital imaging. Let me explain with an example. Suppose you have a piece of artwork or object that you want to copy with as faithful colors as possible, for example a red white and blue flag. Traditionally you might take a photograph of this develop it, and print it. You might then compare the colors to the original and then add and or substract color filters until the print has the same colors as the flag. This process of developing corrective filter values is a "profile". For example different films will render colors slightly differently -- a profile measures this and supplies adjustment curves to neutralize the differences between films. Likewise each scanner might respond slightly differently to different colors, and each monitor might display colors slightly differently and each printer and each type of ink and ultimately each paper. Profiles are typically made using color targets just as with traditional color darkrooms, and densitometers that precisely measure colors so that linearization curves can be developed for each brand of film, (or digital sensor on a camera) each individual monitor, scanner, printer and each brand of paper such that an image is printed as close to the way it looks on the screen as possible. Some people make individual profiles for their own printers and each brand of paper they print on. Creating such profiles requires an expensive densitometer (at least creating a high quality profile does). Some profiles are created with sampling a few colors, and others by sampling hundreds of colors. "Free profiles" are typically created by the manufacturer of a paper for use with a particular brand of printer. "Pro" printers such as the Epson 4800/7800/9800 are linearized by hand at the factory and as such have a profile built into them, but there is much more individual variation with consumer grade printers. To correct for the printer to printer variations many people have custom profiles made by printing out a target (blocks of color) and having someone with a densitometer (and a piece of software) create a profile which is a file with a file type of "ICC" or "ICM". IMHO the most important feature of the full Photoshop program is that it is entirely profile enabled. Now if you find the learning curve too steep, why don't you simply use a Mac and a digital camera. When you plug the camera into the Mac (via a cable) the iPhoto program will launch itself and you can print out the photo. Or get a printer that the camera plugs into directly and you don't even need a computer. If you want film, try shooting in C41 (slides and b/w also work), get a scanner, get the Vuescan program. Scan the neg and then load it into iPhoto. As long as you are happy with the colors don't worry and just be happy. If your prints don't look the same as your computer screen then profile your monitor (System Preferences -> Monitor -> Color -> Calibrate ...). If you still aren't happy with the colors then try adjusting them with the sliders. If you still aren't happy then you need Photoshop where you can deal with profiles for your printer/paper and you can apply all sorts of color adjustment curves etc ...). If you aren't happy with this advice, then as we say: "There are many ways to skin a cat" but this is one way to skin a cat from someone whose skinned some cats. Jonathan