4 Replies Latest reply on Jul 1, 2011 3:55 AM by Maria964

    Best way to deal with screen captures?

    Maria964 Level 1

      Hi everybody,

      I have a lot of images captured with Snagit  (computer screens). They are going to be printed in black and white.

      Usually I do like this: open png file in Photoshop, select Mode to transform in grayscale and save as PSD.

      Generally I obtain reasonably good results in the printed books (CMYK and B&W). [If I have to scale the image I usually do that in Photoshop, but if the budget is tight I do the scaling in Indesign.] I admit that I am not a very good «Photoshoper» and I notice that under Image -> Adjustements there is a command to transform images to B&W.


      I have played a bit with this two options and I have concluded that the the resulting grayscales files obtained with this different metodes are a bit different.


      Can anyone advise me about the best method to use and about the best way to do this kind of convertions in Photoshop. I am on Windows using CS 5.5


      Thank you in advance.



        • 1. Re: Best way to deal with screen captures?
          John Hawkinson Level 5

          Grayscale and black-and-white are not the same thing.

          Grayscale implies each pixel can have a value from 0 to 255, or 256 different possibilities.

          Black-and-white implies each pixel can have TWO values: black, and white.


          These are not the same at all.

          Exactly how is your final document going to be printed?


          On an offset press? Ask your printer what the linescreen and dpi are. This matters.


          Typically, though, you should avoid black-and-white. But: because ultimately somewhere down the line, for almost all output devices, such as offet presses and laser printers, everything has to be converted to black and white, no gray, there may sometimes be advantages to doing that conversion earlier. You will retain more control.


          But usually it is not worth the confusion and the liklihood of error if you do not know exactly what you are doing.

          1 person found this helpful
          • 2. Re: Best way to deal with screen captures?
            Peter Spier Most Valuable Participant (Moderator)

            Actually, in Photoshop, Black and White is really a neutralized RGB image -- three channels balanced to have the look of a B&W photo. If you want pixels that are either black or white, nothing else, one channel, you must convert to Bitmap mode.


            In the same way, "printing in black ad white" is not accurate -- you print in Black, and leave everything else without ink. To get gray you would use a halftone screen of some value.  I would imagine that if you are printing monochrome (any single color, including black) you will want to convert to grayscale, not bitmap mode. You might, however, want to use the Black and White conversion first, which allows you to play with the sliders and adjust the contrasts of the various colors in the screen capture to make the image as readable as possible, then convert to grayscale. I prefer to use an adjustment layer for those adjustments, like B&W, that can be done that way as it is more flexible and doesn't alter the underlying image.


            Consensus among users here who work a lot with screen captures is that you can scale in ID and the results will be as good as scaling in Photoshop.

            • 3. Re: Best way to deal with screen captures?
              Scott Falkner Level 6

              P Spier wrote:


              Consensus among users here who work a lot with screen captures is that you can scale in ID and the results will be as good as scaling in Photoshop.

              No. Consensus is that you should scale in InDEsign and the results are better than scaling in Photoshop. You don’t want to change the resolution, in absolute pixels, of your screen captures.

              1 person found this helpful
              • 4. Re: Best way to deal with screen captures?
                Maria964 Level 1

                Thank you John, Peter and Scott for the reply.


                I am very happy to descover that the consensus about scaling is to do that in Indesign. That is faster and as Scott pointed it saves me the trouble of keeping to sets of files (one original size and other scaled). The method Peter uses is very smart and I will use it on my workflow (at least for the books with higher budgets bacause it implies more work).


                This forum rocks and is really a life saver for everybody...




                PS. Do you know what I have discovered last night. I placed a Word file in Indesign (around 120 A4 pages full of text, 60 graphics and 850 Mathtype equations) and Indesign started to work very slowly. For exemple: editing the text took a long time (1 or 2 seconds inser a character)... I work a lot with complex Math books so I am a bit used with Indesign being slow in this kind of work. But yesterday it was too much. See what I have descovered: the word file had hundreds of crossed references and half a douzen of hyperlinks. As soon as I deleted all that stuff and amade a Save As, Indesign started to behave normally.