5 Replies Latest reply: Aug 13, 2013 3:49 PM by rob day RSS

    Scaling Questions

    Sharingene Community Member

      Hello, I'd appreciate your thoughts.... 

       

      I see a lot of discussion about problems when scaling low res images (72 ppi), BUT what about high res images (TIFFs) that start out with an actual PPI of 300, and after scaling in InDesign end up with an EVEN higher Effective PPI?  Will these images print well in offset printing (PPIs of 700 -1300)?  Is there a point where  Effective PPI can be TOO high?

       

      Also, what is the recommended work flow in this situation?  I've compared several techniques... 

      --I've just let Indesign do the scaling, no other sharpening

      --I've applied a little sharpening to the full-sized image FIRST (in Photoshop) then let InDesign scale

      --I've resized in Photoshop using the exact dimensions needed from my InDesign layout, then sharpened

      --I've also tried using both Bicubic and Bicubic Sharper to resize in Photshop and then sharpened to see if one was better than the other.

      --I've also tried using a script that resizes all of your images for you images to 100%, then did my own shapening

       

      So I've been experimenting A LOT and now have way too many verision of this layout!  LOL!

       

      To compare them, I  made PDFs of each different attempt.  Surpisingly, I don't think the images scaled to 100% first, then sharpened in Photohop look as good.  If I pixel peep at high magnification (and yes, I know no one will be looking at the printed project this way) but still, the images resized in Photoshop look more pixelated compared to the versions scaled in InDesign. The absolute best result came from applying some low level sharpening to the full-sized image first (in Photoshop), and then letting InDesign handle the scaling.  By far, this PDF had the sharpest looking results compared to all other attempts.

       

      Am I missing something?!??? After all of this experimenting, I think I know what to do, but this is my first major project and just want to make sure I'm on the right track.  A sincere thanks for your thoughts, ideas, and suggestions.

        • 1. Re: Scaling Questions
          BobLevine CommunityMVP

          They're going to get downsampled when you export to PDF. Unless you

          absolutely need them sharpened a bit then don't worry about it.

           

          If you do, then do it in Photoshop.

          • 2. Re: Scaling Questions
            P Spier CommunityMVP

            You might lose some fine details during the downsampling when the effective PPI is very large, so you'll want to check the PDF.

            • 3. Re: Scaling Questions
              Sharingene Community Member

              Thanks to both of you!  Okay then, l feel better about leaving them in their original sizes with just a touch of pre-sharpening to the critical details. Any guesses as to why the down sampling to PDF through InDesign seems to be doing a better job than resizing in Photoshop?  -- I'm a details person and just very curious about all of this!  Is it an improved algorithm perhaps?

              • 4. Re: Scaling Questions
                P Spier CommunityMVP

                Actually the same automatic algorithm. And downsampling generally sharpens a bit on it's own.

                • 5. Re: Scaling Questions
                  rob day Community Member

                    Is there a point where  Effective PPI can be TOO high?

                  No, so you could turn off downsampling, but you have to watch out for the printer downsampling at output. I've had jobs where an image needed more resoultion (small high contrast type) and the printer sampled it down to 300 on their end.