From: "Elgenper" >RIP is an acronym for Raster Image Processor. Without technicalities >(which I am not qualified to go into anyway...), the important aspect >here is that it is a very capable printer driver that can control the >amounts of ink used for a specific tone very closely, and thus follow a >colour profile very closely. the many different flavours (there are 60 or so RIP manufacturers) also have the potential to nest images intelligently to conserve space, resize incredibly well, lay colour accurately, sharpen accurately, inrease or decrease ink volumes or any number of things beyond the capabilities of the basic print driver, which BTW is a basic rip in it's self. The problem with the RIPs inherent in most small printers is that they have only a teeny amount of memory and a basic instruction set as to how to do things. we know this as being part of the printer without realising it is actually a RIP. as an example, some B&W HP laser printers can do multipage layouts and some even nest. these may be things we do not see on some colour printers because the RIP isn't capable of this. Those who DO have that ability frequently don't realise this is the tip of the iceberg regarding what is possible .. then there are the hardware rips. Hardware rips are really just software rips on a separate computer acting as a print server. this means they can handle the print upsizing and conversion remotely without bogging down the working computer - you send the image to print and off goes the little 1Mb image to the 'printer' (the hardware rip) and off you go back to work. the 'printer' receives the job, rasterises the image and depending on the quality of the rip, the processes of upsizing begins to produce a colour accurate, large image. the image may be blown up to some pretty huge sizes and the need for sharp, well interpreted results are needed which is where the quality of the rip comes into play. In effect this small 1Mb image may be increased in size to 40 terabytes with the quad cpu puter working it's guts out for quite a while to achieve the results, then it is converted into postscript or some other language that the printer can handle in small chunks (remembering the memory limitation of the printer) then the job is fed to the printer. I had the pleasure recently of working with a hardware rip that held 50 terabytes of hard drives and 16 cpu's :-) it's hard to describe the results - a tiny little 3000x2400 pixel image sent to print coming out 44" x 55" managing to look incredibly sharp and extraordinarily good, in fact better than the small original (it's an algorithym thang :-) Using such a sophisticated tool it made me realise we photographers have come a lot later to digital than our graphic designer cousins, and by and large we've hijacked quite a few graphic design tools to manage our work but there are more to play with (and some that should be abandoned!). RIPs are something I've found many photographers have yet to explore, yet they are the final step in achieving the results we crave and they amy be the ONLY way to get good large prints. btw, they're not cheap. >The one I was referring to (QTR) controls >B/W printing by stopping the printer from using any yellow ink at all >(normally an inkljet makes middle grey tones by mixing yellow, magenta, >and cyan inks; since the yellow ink looks different under daylight and >artificial light, such a print will display strange colour shifts in >different lighting, which is metamerism sounds like a nice one, thanks :-) k
