HELP -Rescaling from 1:50 to 1:32, 1:33

Discussion in 'Tips, Tutorials & Tools' started by dimas Karabas, May 10, 2005.

  1. dimas Karabas

    dimas Karabas Member

    Dear Experts!

    I need your help, after looking over a number of forum entrees dedicated to reprinting and scanning and especially awesome tips by Leif Oh, I am still little bit confused.

    I do understand now about printing and white noise but before I even get there I would like to have a simple explanation as to how turn 1:50 model in PDF format to 1:32 or 1:33.

    First of all what programs to use. I tried using Photoshop and open PDF files in it, but it would freeze on me and eventually crash. By the way the PDF files are not protected.

    Then I used Corel Draw, I would import the file, increase the image to 150% and would print parts that fit on each page of letter size. (I do not have any larger paper at this time)

    However, it turned out that in Corel the colors are somewhat faint as compare to the same print in Adobe Acrobat. What is the problem here?

    And what is the right conversion ratio, is it %150 or less? (Math is not my strongest point)

    Thanks for your help.

  2. murban

    murban Member


    to convert from one scale to another, you could either use a small utility program called "Scale2Scale" that is available at

    (you might need to register to get to it). It works on image files only, but you could save your PDF as jpg from Corel.

    To calculate manually, you only need to multiply with the old scale factor and divide by the new one.


    From 1:50 to 1:33 -> factor is 50/33 = 1.515 = 152% (roughly)

    Other example: From 1:200 to 1:250 -> 200/250 = 0.8 = 80%

    Hope this helps a little...

  3. dimas Karabas

    dimas Karabas Member

    Thanks Michael.
  4. 46rob

    46rob Member

    Once you've got your new multiplication ratio--using photoshop--first convert the pdf to a photoshop document, using the "save as" function. Then enlarge the entire page by the amount you calculated and then cut and paste the pieces onto a newly created document sized to 7.6 x 10.5 inches for standard letter sized paper. Make sure your new document has the same dpi as the original. Use the RGB color mode and each piece copied and pasted becomes a separate layer. Use the "magic eraser" tool to remove anything outside the part. You can draw complete sheets of parts this way, and move, rotate etc each piece for optimum efficiency. After it's all done, you can merge the layers and save as a pdf again if that's the format you really want.
  5. dimas Karabas

    dimas Karabas Member

  6. dimas Karabas

    dimas Karabas Member

    Hi Rob,
    I did as you said. But when I copied a piece of sheet with parts on a new page, it turned out to be bigger then the page like 5 times? Why is my copy so big?
  7. Leif Oh

    Leif Oh Member

    Dimas, most likely different resolutions. Check in the appropriate box or menu what is the resolution of the original - 300, 150, 72 dpi?

    Now, you've got to decide on what resolution you wish to work in. For simplicity's sake, let's say that you choose the one of the original, let's say 300.

    Then open up an empty page, set the resolution of that page to 300, and paste in what you've copied. Should work.

    Getting the hang of resolutions and how that work took me my first year of paper modeling, or more, so don't despair. You should be able to get it MUCH quicker, since you've got the rest of us to troubleshoot.

    Incidentally, a good tip is to bring out the rulers of your graphics programme. Size is not always what it seems to be on the screen. An image can look incredibly big on the screen (like a .TIF drawing, if you ever downloaded one of those), but that's just because every pixel is shown at the screen resolution (72 dpi if I'm not mistaken). The actual printing size may be MUCH less. The easiest way to spot that is to check against the rulers of your programme.

    As far as I can understand (off the top of my head) this is because the actural SIZE (metric or inches), or SCALE, of such an image determines that it should be printed at quite another resolution (higher), but that is not shown on the screen, other than measured against the rulers.

    Another example: One of my typical scans at 150 dpi needs to be viewed at around 62 percent size on the screen to show up as full size (as measured by a physical ruler, brought up against the screen). A scan at 300 dpi must be viewed at around 31 percent to show up in actual size on the screen. These figures have to be determined by actual comparison of the ruler on the screen, with a physical ruler brought up against the screen to compare. (Check a bit down on this page for an exampel of how that might come in handy. )

    All of this is just rambling. Stick to the first advice, and check the resolution of your original. Will be interesting to see if that solves the problem.

  8. pixelkeg

    pixelkeg New Member

  9. 46rob

    46rob Member

    One thing more--although photoshop can work in just about any format--it's happiest when working in it's own--and most efficient. Alway try to work in the highest resolution your machine can handle. Too high and it can get really slow. Too low and your lettering and small detail comes out fuzzy. I generally develop my detail as smaller separate drawings at a higher resolution and then reduce their sizes and paste them onto my model.

    Example if the model is normally 200 dpi--I do my lettering at 300, reduce it dimensionally by 1/3 and paste it onto my model. Photshop does it's magic and everything fits perfectly.
  10. dk

    dk New Member

    Thank you all for the priceless advise! It really helps to have people share combined knowlege in one spot. God bless internet!!!
  11. Leif Oh

    Leif Oh Member

    No problem, happy to help. But more importantly, be sure to report if, and when, and how, it worked out for you. Might help others... - L.

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