6 Replies Latest reply: Feb 17, 2010 9:24 AM by on5lb RSS

    About the 72ppi

    on5lb Community Member

      Hello,

      Is there some expert who can give me the justification to still using the "mytholobical" 72 ppi for images ?

      I have as an exemple, the images presented into the latest famous "ClassRoom in a Book" for Photoshop CS4 Extended.

       

      How many people are still using a monitor limited to such resolution, or is the reason only justified by using the WEB ?

       

      I use computers specifically devoted to Vision Images Analyzes, and they are NEVER connected to the WEB !

      I'm certainly not an exception !

       

      I'll be pleased to receive a logical reason.

      Regards,

      Jean

        • 1. Re: About the 72ppi
          John Joslin Community Member

          I think this article says it better than I could!


          http://www.scantips.com/no72dpi.html


          The whole web site is worth perusing.

          • 2. Re: About the 72ppi
            dec9 Community Member

            Sa weet site.

             

            • 3. Re: About the 72ppi
              on5lb Community Member

              Hi John,

              Thanks for the link, but it does not change anything to the problem, unfortunately !

               

              All software "creators" are sending "Upgrades" to the infinity, as an argument of "Performance".

               

              But about resolution...we still are living the early '80s !

               

              I grow up with pixels from 1976 and started, in 1979, using digital cameras from Pulnix (made in UK) as a 320x240 pixels definition !

              Black & With, of course

              Comprared to the technical possibilities to day !

              At that time, we already implemented the use of Frequency Distribution Algorithms mainly for alignment and inspection on automatique High-Speed Diebonder.

               

              We used Subpixels as well as Pseudo-color wich facilitates interpretation of images during Teach-In.

               

              I'm complaining about this stupid decision since decades, but yes, i know...custommers are so easely to be manipulated.

               

              All the best John,

              Jean

              • 4. Re: About the 72ppi
                Bill Hunt CommunityMVP

                Jean,

                 

                Where are you running afoul of images at 72 ppi? Considering that one can quickly change the resolution to that desired, what is the problem that you are experiencing?

                 

                Good luck,

                 

                Hunt

                • 5. Re: About the 72ppi
                  Community Member

                  You are seeing 72ppi in Photoshop because the program has a required data input field in the image size dialog. It is required for other functions, such as rendering rulers in the interface.  It, like many other functions in Photoshop, is based on very old code that isn't exactly broken so it is not being fixed.

                   

                  Video and web artists ignore this dimension as it has never applied to them, ever. It is just a placeholder value.

                   

                  72ppi is not used for the web or any onscreen image display. If you save out a JPG using Photoshop's 'save for web' function, resolution data is removed from the image.

                   

                  You can confirm this by viewing the image in Bridge to see 100ppi for a 'saved for web' image or by viewing the image in Photoshop to see 72ppi for a 'saved for web' image. These programs attach an arbitrary resolution to any image file without resolution data.

                   

                  If you don't want 72ppi (or any ppi), save for web.

                   

                  You might file a feature request with Adobe to remove the required resolution field from Photoshop's 'image size' dialog if the image contains no resolution data... as I have.

                  • 6. Re: About the 72ppi
                    on5lb Community Member

                    Hello Marian,

                     

                    Thanks for your detailed comment, Marian.

                    I finally received a logical answer, which is quit exceptionnal on Forums !

                     

                    I understand the arguments you mention, but it should be modified for now.

                     

                    I know "resolution" has nothing to do when we talk about TV or monitor screens, in that case we use the "Definition" term,

                    which are the number of pixels we have: horizontal and vertical of the screen.

                     

                    And the "resolution" term is only justified when we're talking about printers.

                     

                    The fact is that i like to print some specific images, (using a Tektronix Phaser printer).

                    At 72ppi, it's realy a disaster !

                     

                    There is a Belgium french citation who said: "Qui peut le plus peut le moins"

                     

                    If i try to translate, it's looking like: "If you can do more, you can do less"

                     

                    Which mean, you can do less if you have more, but you cannot do more if you have less.

                    You can reduce from 300ppi to 72ppi, but how about 72ppi to 300ppi ...except by using "Interpolation" as the well-know "Bayer" filter

                     

                    All the best Marian, and thanks again,

                    Jean