CompuServe Thread

Michael, As an imagesetter operator, and as a former purchaser of imagesetter output and now as a consultant re imagesetter output (I am about to give a 3 day seminar here on Maui as a result of popular demand!) I recommend that you advise your customers NOT to use either the 'Negative' or 'Mirror Image' settings. You are only asking for trouble and will unintentionally mislead those whom you advise to use these settings. I appreciate the fact that you and your service bureau have apparently gotten comfortable with the combination of settings that you have indicated. I also appreciate the fact that _theoretically_ these settings should, especially in the hands of someone who understands _both_ PostScript well and the mechanics of the photomechanical reproduction process result in predictable output. Unfortunately, that is not the case. In the real world things don't always work as they should. I wrestled with this problem for quite a while, insisting to myself that if I put the correct instructions into the PostScript file, that the PostScript output device would faithfully obey the input stream. This is one of the situations in which communication between the creator program and the behavior of the PostScript output device just cannot be taken for granted. Take one of your files and send it to a number of different service bureaus. Give them no instructions, other than to output the file. The results will be a mix of results – probably 70% will have the wrong combination of Negative/Mirror attributes. Anything less than 100% reliability is unacceptable. The reason for this problem is not PostScript itself, which actually _is_ 100% reliable. It is the result of several years of general confusion regarding how to teach a suddenly exploding population of otherwise intelligent, but inexperienced (in printing industry matters) computer users just what Negative Image, Right-reading Emulsion Down, Right-reading Emulsion Up, Mirror Image, Reverse, Inverse, Horizontal Flip, Vertical Flip, Normal Image, etc. actually [ MORE ]

[ continuation ] means. Imagine the plight of the imagesetter operator trying to anticipate just what he is dealing with from a myriad of sources. Some files have one of the Negative/Mirror operators on, some both, some neither, and almost none of the senders of such files can really tell him what combination they have actually sent him! Chaos. The only way to avoid the chaos is to assume that every file has _both_ operators off and to isolate the PostScript interpreter from that particular kind of PostScript code. This requires the imagesetter operator (human type) to manually control the machine for Negative and Mirror output. Some manufacturers have done just this. Unfortunately, they have not been consistent across their model lines, and some cannot even tell you which of their machines do this or not! Therefore, the only way to get reliability, is to leave these settings alone. Always prepare output for an imagetter as though it is intended to print as a positive image with the image unreversed left to right, looking at the emulsion side of the imaging material. In other words, the way it would look coming out of a laser printer (or dot matrix for that matter). Then tell the service bureau what kind of output you need. Let them control their machine in this respect. True, after dealing with a particular bureau, they may tell you to prepare your output in a different way. But as general advice, I stick by my position. Also, many imagestetters _do_ image all the way to the edge of the imaging media. Mine images all the way to the edge of its 12 inch capacity. The user _should_ ask the service bureau what their capability actually is. But I certainly won't argue that 11.7" on a 12 inch machine is a conservative number which will avoid some potential problems. Unfortunately, it will also limit some jobs which need that last few millimeters to get the crop marks on. All this discussion underlines the importance of treating output to a high resolution device differently from sending output to an 8.5 x 11 capacity laser [ MORE ]

[ continuation ] printer. It is NOT plug and play. I strongly recommend that anyone needing to use a service bureau contact them first and ask all the questions they can think of, THEN ask the bureau if there are any questions that they _should_ have asked but didn't. If the service bureau is not willing to spend the time answering all the questions and making every effort to assure correct output from the get go, seek another bureau. Also be prepared to pay for output OR output time if problems in output are the fault of the sender. We're updating our order sheet/advice form for imagesetter output. I'll send you a copy . . . no, I'll send you the Pgs file when it's done. 8) Rich

Well, I would have to say that, in my experience, advising novices to set both mirror and neg is a recipe for _real_ trouble!! If all you want is a straight bromide that looks like the output of your laser, then mirror & neg must not be set unless the bureau specifically asks for them to be set (some bureaux have their setters set to produce mirror/neg for film output, and so you need to set them again to make sure it comes out right). The only time I've ever had to set mirror/neg was when I was going straight to film for plate production, and I wanted mirror/neg output. Of course, if your bureau is going to do the final printing for you, then maybe they too would like mirror/neg. If I were ever in any doubt about what was required I'd discuss it with the bureau before doing anything … and that would be infinitely better advice than getting novices to set mirror/neg!! Mike (from the UK)