CompuServe Thread

#Printer output& format

12 messages in this thread
#174681From: Robert J.P SmithJun 10, 1995 10:20 AM
Hi everyone, Just read the thread on the printer output and need extra info please. Have an associate with Kodak Color printer with 300 DPI resolution. Actual print size on paper ends up being 7 1/2 (high) by 10 inches wide. Rendered test.TIF image at 800 x 600 with aspect ratio of 1.0, null device, no display. Photoshop is being used to send to printer. Color Print obviously because of resolution had some anti-aliasing on it but Why would the colors not be exactly the same as seen on a monitor when using my TARGA card with a res of 512 x 480 ?. First thing I will do is render to higher resolution: 2250 x 3000. Question: If image is rendered as a JPEG instead of a really large TIF will there be a loss of picture quality when it is brought into Photoshop ? What would be the ideal PIXEL size to select.. am at 1.15 now. Any other switches that need to be clicked on ? What about in Photoshop does he have to change any of his default settings ? thanks for your assistance.. Bob Smith
#174708From: EDWARD HARVEYJun 10, 1995 3:14 PM
<< Why would the colors not be exactly the same as seen on a monitor when using my TARGA card with a res of 512 x 480 ?. Because what the viewer sees when looking at prints is color form reflected light, some of which has been absorbed by the print whereas the monitor is light itself shot right into our eyes. Therefore there can be no exact coraspondance. Some colors that you see on the monitor cannot be printed so it is very important to send the printer a CMYK file( Photoshop .PSD ). After you convert the RGB file ( TIF, TGA or whatever ) to CMYK in photoshop you will probably need to adjust the saturation of the colors or of a particular color channel to get close to what the image looks like on the monitor. If the printer does this conversion, you leave the final output to chance. Hope this helps. Ed
#174727From: Robert J.P SmithJun 10, 1995 7:26 PM
Ed: you say: <<Because what the viewer sees when looking at prints is color form reflected <<light, some of which has been absorbed by the print whereas the monitor is <<light itself shot right into our eyes. Therefore there can be no exact <<coraspondance. But wait a minute a slide projected on a wall or even scanned then brought into photoshop and sent to print will show the exact colors.. <<Some colors that you see on the monitor cannot be printed so it <<is very important to send the printer a CMYK file( Photoshop .PSD ). Ok so you bring it in as a TIF or JPEG.. any idea by the way if a file that is a JPEG at say 2000 x 3000 will give as good an image to send to the printer as a 2000 by 3000 TIF ? I ask since it can be easier to transfer a 500 K JPEG than a 7 meg TIF.. <<convert the RGB file ( TIF, TGA or whatever ) to CMYK in photoshop you will <<probably need to adjust the saturation of the colors or of a particular color <<channel to get close to what the image looks like on the monitor. <<If the printer does this conversion, you leave the final output to chance. So what your saying is that there is no automatic way to make sure that the file I render in 3DS and see with the colors that are correct will turn out exactly the same on a print ? I must be missing something here cause I cannot believe that handing over a diskette with a TIF on it and saying to the bureau that the file needs to be 8 x 10 or 11 x 14 and that ther might need to be more done to it.. I mean if my object MUST be a certain color and it's OK on the monitor then it has to be the same on a print, no one can stand around and do color adjusting..
#174767From: EDWARD HARVEYJun 11, 1995 2:43 AM
<<So what your saying is that there is no automatic way to make sure that the file I render in 3DS and see with the colors that are correct will turn out exactly the same on a print ? I must be missing something here cause I cannot believe that handing over a diskette with a TIF on it and saying to the bureau that the file needs to be 8 x 10 or 11 x 14 and that ther might need to be more done to it..>> Welcome to the wonderful world of printing and monitor calibration(G). If what you believe is true and there is an automatic way to guarentee exact results in printing then one would feel free to order 10,000 copies of something without proofs. No one in their right mind would do this; everyone gets proofs to check the output before printing an order because, believe it, there is no 100% predictable results in printing from a digital file without proofing. You mention your monitor but if you were to look at several monitors side by side showing the same image there would be differences. Which monitor shows the true image? Since monitors start out different, get more different with age and are adjusted out of factory settings by users, its clear that one cannot regard any particular monitor as a perfect standard. At the printers end different machines have different output characteristics and need to be calibrated too. On top of this TIF files are RGB which is a different color space than the CMYK system used in printing. You can test this by converting a very vivid TIF image with lots of intense colors into a PSD in Photoshop, then look at them side by side. You can see the difference. So there are all kinds of ways that things can get out of whack. You may get perfect results one time or several times, but you may not, and probably wont, without some attention to calibrating your monitor to the specific printing device you use for output. Kodak and other software companies are trying hard to perfect monitor and scanner calibration software so these problems will be mitigated. The best solution Ive found was to calibrate the gamma settings in photoshop so they matched ( as close as possible ) the prints I was getting from the service bureau. Now Im calibrated so my monitor matches the printed output (and Im not wasting $40 a pop on Iris prints that dont look right) . <<Ok so you bring it in as a TIF or JPEG.. any idea by the way if a file that is a JPEG at say 2000 x 3000 will give as good an image to send to the printer as a 2000 by 3000 TIF ? I ask since it can be easier to transfer a 500 K JPEG than a 7 meg TIF..>> I will say it again, this is a predictable method ONLY if you provide the service bureau with CMYK files; with TIFs the printer is making the conversion and he has not seen your monitor. So both JPG and TIF have potential problems. If you insist on sending an RBG file I would run tests to check if the compression causes problems that are unacceptable to you. I think that certain types of images show artifacts more especially along hard edges and flat color areas. There are lots of variables here and people write text books on this stuff, its that complex. Im not an expert but Ive understood it well enough to get predictable results. Your amazement that this isnt a totally nailed down and predictable process reminds me of how indignant I was when I found out that color photographic paper cannot be produced with consistant sensitivity and therefore light settings in the enlarger must be changed for each batch of paper. It may look like science but its an art too. Good luck Ed
#174906From: Robert J.P SmithJun 12, 1995 9:43 AM
Edward, First thanks to you and James for the info sent over the weekend but as I just wrote to him and said: I have a bit of a problem with part of what you said: << everyone gets proofs to check the output before printing an order because, << believe it, there is no 100% predictable results in printing from a digital << file without proofing. I agree.. Anyway there could be slight variations caused by new or old chemicals.. the age of paper etc.. let alone as you mentioned the age of my monitor etc.. but the point I'm trying to get at is that if the image I'm looking at on my monitor with 3D Studio or on his monitor when he calls it up on photoshop looks basically the same but changes when it comes out on a print.. then I assume there should be some tweaking that needs to be done in Photoshop so that the print looks the same and all futur prints will also have a close or even perfect match.. I mean do I bring in a TIF with a color bar on it and we look to see where the differences are or is it slight alterations to the Gamma correction or whatever photoshop.. that's what I'm trying to figure out.. << I will say it again, this is a predictable method ONLY if you provide the <<service bureau with CMYK files; Ok.. How do I provide them with a CMYK file ? Thanks again…
#175010From: EDWARD HARVEYJun 12, 1995 6:30 PM
Robert << How do I provide them with a CMYK file ? In Photoshop ( I have 2.5 ) open the TIF , go into the mode menu and check CMYK color. The image will be converted to CMYK. Save the image as a PSD file. Now you can open the TIF again and see if there are any differences between the images. The usual difference is that the colors will be slightly washed out in the PSD. You can correct the PSD with brightness and contrast, hue and saturation and color balence from the image/adjust menu. Correction is a whole set of skills in itself and requires knowledge of color to be really good at. Computer Artist Magazine has a series of articles by Dan Margalus on color correction thats really excellent. But you can learn a lot by experimenting. For advanced users you can open the channels window in the window menu and see the seperations of the cyan magenta yellow and black channels. Manipulating seperate channels is complex however. When you give the printer the PSD file you are providing CMYK information which gives you the greatest control over the output. But you could still have unpredictable results so heres a good way to get calibrated. 1) Do the above process resulting in a CMYK PSD file with an image which has a wide range of colors from the whole hue spectrum, dulls and vivids and lights and darks. Its a good idea to include color bars on the edge of the image. 2) Have it printed. 3) take it home and compare it to the image of the same file on your monitor. 4)Go into File/ preferences/monitor setup. In the dialogue box go into calibrate. In the calibrate box you can change things (read the docs carefully ) until the image on your monitor looks as close as you can get to the print. Dont forget that room light ( tungsten versus incandecent ) and other things can affect the look of the print. When you get as close as possible save the settings. You will have to have different monitor settings for different types of printing devices. Now you are calibrated with the particular printing device and should get predictable results. Some printing devices such as color copiers are difficult to keep adjusted so if the printer dosnt keep it steady you should find another service bureau. I think the best prints are Iris prints but they are expensive ($40 for 11×17 ) Dye sublimation prints are cheaper and are good quality. Its worth the trouble to get consistant. A knowledge of RGB and CMYK color spaces and color theory in general really helps. Ed
#175270From: Robert J.P SmithJun 13, 1995 10:24 PM
ed: Went thru the info you sent me with the guy who has the Kodak printer and he says that the printer he has is the XLS 8300 and takes in RBG files only.. goes up to 300 DPI he says it does not take CMYK info … Meanwhile, must admit that once I increased the resolution to my image ( my test image was 800 x 600 ) but at that resolution it becomes 72 bits per inch.. That print turned out nice but fuzzy and not sharp.. I re-rendered the file to give 300 bits per inch: 3000 x 2250, the print was amazing and the difference in colors seen on the print and the monitor image was minimal… it's a very slight difference but I guess that's what will happen with sending a TIF file to this printer .. Will try tomorrow to see what another test image but this time at 2133 x 1600 will look like since the 3000 x 2250 took 2 hours to render and I find that just a tad long.. Thanks for your help,
#175290From: EDWARD HARVEYJun 14, 1995 1:03 AM
Good, Im glad its working out. the information on calibration of the monitor will work whatever files you use. The info in CMYK will be useful if you ever use another printing device. I just let the long renders go overnight.
#174748From: James Coulter[Mindscape]Jun 10, 1995 10:34 PM
> Why would the colors not be exactly the same as seen on a monitor when using my TARGA card with a res of 512 x 480 ?. < Are you asking about a difference in viewing the same image in Photoshop and 3DS and seeing different colors? Pehaps your Windows configuration is not using the same color-depth as 3DS, or maybe the Windows palette is having an influence. If you're wondering why a printed image has different colors, well, this a field unto itself. The fundamental issue is the difference between projected light and reflected light. Among other things, the ambient lighting in your office will affect the color you see reflected off the printed image. As for the difference between your NTSC monitor and your RGB computer screen, take a look at the thread titled "?PAR/SCREEN Colors" in this same forum section. — James — Choreo Motion —
#174905From: Robert J.P SmithJun 12, 1995 9:43 AM
James: By the way, did Bill Allen reach you ? He was thinking of putting in that article of yours on OS2.. It still works with Warp also and that's why he was interested.. Anyway… Here is another question on the problem I'm having concerning some slight differences in "some" colors I see on a monitor using the TARGA card and the Color print I got with the Kodak printer.. <<If you're wondering why a printed image has different colors, well, this a <<field unto itself. The fundamental issue is the difference between projected <<light and reflected light. Among other things, the ambient lighting in your <<office will affect the color you see reflected off the printed image. So if I understand what you and Edward harvey wrote to me on the weekend… I output from 3DS as a TIF (or a JPeg) at Hi resolution and the file is then input into Photoshop.. Now is where I'm foggy.. Before the file is sent to the printer does it need to be "SAVED AS" something else "then" sent to the printer… Bob <<As for the difference between your NTSC monitor and your RGB computer screen, <<take a look at the thread titled "?PAR/SCREEN Colors" in this same forum <<section. Checked for the Par/SCREEN colors thread and it was gone..
#175875From: James Coulter[Mindscape]Jun 17, 1995 2:23 AM
> James: By the way, did Bill Allen reach you ? He was thinking of putting in that article of yours on OS2.. It still works with Warp also and that's why he was interested.. < I'll give him a call. I sent it to him months ago, but I figured he wasn't interested after the news that 3DS was moving to NT. I guess some folks might find it usefull between now and when they upgrade to R5. > Before the file is sent to the printer does it need to be "SAVED AS" something else "then" sent to the printer… < Nope. However, you might consider switching the image to CMYK color (look under the Mode menu). Ed's comments along these lines are right on the mark. Let me re-emphasize that calibration is going to be only an approximation at best for a myriad of reasons, but it does help. > Checked for the Par/SCREEN colors thread and it was gone.. < From Message #174747: "In addition to what others have said, keep in mind that RGB displays devices have a larger color space than NTSC devices, mostly because of the signal type. This means that it will be difficult or impossible to get the overall contrast/chroma on your NTSC that you see on your RGB. Gamma is intended to compensate for this to some degree, but it's not perfect because the colorspace just isn't there for NTSC. A better solution is to get a framebuffer and develop images on your NTSC right from the get-go. This way you don't suffer from "chroma-shock" during the conversion." Robert, if you're goal is get the closest approximation of a printed image, stick with editing on your RGB monitor. — James — Choreo Motion —
#175982From: Robert J.P SmithJun 18, 1995 4:15 PM
<<A better solution is to get a framebuffer and develop images on your NTSC <<right from the get-go. This way you don't suffer from "chroma-shock" during <<the conversion." <<Robert, if you're goal is get the closest approximation of a printed image, <<stick with editing on your RGB monitor. James, thanks for info, but since most of my output is towards video tape I always ended up checking the colors thru either my Targa card of the Par card to make sure the colors were correct.. and when I did the test towards the printer last week, I checked the print colors against the image I output to the Targa and found little or no difference and here's something that suprised me: I rendered test 1 at a really high resolution so that it would give a 300 DPI ..that was sent to printer.. then I re-rendered the image at a resolution for 150 DPI and obviously is took half the time to render..(from 2 hours to 1 hour) and the color print done at 150 DPI came out so close that I had to use a magnifying glass to tell the difference.. So no use wasting time rendering to 300 DPI.. Bob Smith