13 Replies Latest reply on Nov 16, 2009 1:09 PM by Jim_Simon

    True black on screen

    k9tag

      I am getting back into Premiere after a long absence and I'm starting into pro/cs4 with a simple project that involves a bunch of 1920 x 1080 images with music underneath.  Does it matter so much what DPI I use for my images? 72? 300?  Some images will be just black backgrounds with text on them and I want the text to appear very clearly on the various flat panel displays.  In the past,  I have used what I thought was a black background when creating such images in Photoshop only to find that what I thought was black ended up looking kind of dark gray onscreen.

       

      So .... what do I do with black in photoshop to get a "true deep black" to appear on the screen, and what dpi should I use with these "photoshop to video" images in order to make sure that the text in the images appears clear on screen?

       

      Any help appreciated.

       

      Thx,

       

      -Mark

        • 1. Re: True black on screen
          the_wine_snob Level 9

          Mark,

           

          This ARTICLE should give you some background on Super Blacks (and Super Whites). Especially, follow the link to the FCP article that I mention in reply #6.

           

          Good luck,

           

          Hunt

          • 2. Re: True black on screen
            Harm Millaard Level 7

            DPI is completely irrelevant for video. Only pixels are relevant.

            • 3. Re: True black on screen
              k9tag Level 1

              Hi Hunt,

               

              Thanks for the info.  I am sure that here is something in there somewhere that might help me, but not that I understand.  I don't have FCP, so no help there.  I just need to know what I have to do differently with black in Photoshop CS4 for the 1,000 images with black backgrounds that I am about to create.  I want black to appear black onscreen rather than dark gray.  Maybe nothing to do in photoshop except leave blacks at R0 G0 B0, and then do something else in premiere pro or in encore to make sure black is black?  Seems fundamental.  Black needs to be black.  If there is a special procedure to make black appear black onscreen, it needs to be on page one of all Premiere Pro training docs.

               

              -Mark

              • 4. Re: True black on screen
                the_wine_snob Level 9
                I don't have FCP, so no help there.

                 

                Don't let the references to FCP get in the way. It is the underlying theory that is important, and will apply to PrPro too.

                 

                Now, I assume that you are working in NTSC-land. Is that correct? Things are a bit easier in PAL-land, as Harm can attest.

                 

                What is your delivery scheme? What happens with NTSC material meant for TV display, is that the output will normally be limited to 16 and 236.

                 

                This ARTICLE might shed some more light on the issue.

                 

                Good luck,

                 

                Hunt

                 

                PS - Harm is correct on the DPI/PPI aspect. I meant to comment on that, but got hung up on Super Whites and Super Blacks. The DPI of your images will have no effect on your dark grey/light grey.

                • 5. Re: True black on screen
                  k9tag Level 1

                  Yes, NTSC.  Here is the delivery scheme ===>  I will take these 1000 images, some with text, some with black backgrounds, and will add an audio track or two ... all on a timeline in premiere pro.   ====>  I will send that to encore / media encoder to produce a dvd that I can play back on a wide screen tv.

                   

                  If I make something black in photoshop, I want it to appear black on screen.  I'm not really interested in getting into any theory right now, i'm just looking to find out if there is anything that I can do in photoshop or elsewhere to make the blacks appear black onscreen, short of moving to Europe and using PAL.  If nothing can be done, I will accept that and move on.  If there is something I can do, I will create all of my images accordingly.  There is no input video for this project.  Just images created in photoshop.

                   

                  When you say  "the output will normally be limited to 16 and 236"  ..... I don't understand what 16 and 236 is and how it relates to the black issue.  Again, it has been a while since I made a video and I didn't know what 16 and 236 meant then either.

                   

                  Re Harm's comment that DPI does not matter.  I will need some convincing on that.  When I create a 1920 x 1080 image in photoshop and fill it with what i think is black, then type a word in the middle of the screen, add some effects, etc., and then ........

                   

                  ....if i do an image size to change this 1920 x 1080 image  from 72DPI to 300 DPI, the text appears much clearer on the screen which I assume will translate all the way down the line.

                   

                  ..... if I do an image size to change this 1920 x 1080 image from 72 DPI to 2 DPI, my text ends up looking like a pile of goo which i assume will translate all the way down the line.

                   

                  So,  to me it looks like DPI very much matters.  I know 300 DPI is overkill, but there must be some optimal DPI that I should be using for this type of image to be used in the video?

                   

                   

                   

                  -Mark

                  • 6. Re: True black on screen
                    the_wine_snob Level 9
                    If I make something black in photoshop, I want it to appear black on screen.  I'm not really interested in getting into any theory right now, i'm just looking to find out if there is anything that I can do in photoshop or elsewhere to make the blacks appear black onscreen

                     

                    Mark,

                     

                    Unfortunately, it's that "theroy" that drives it all. In NTSC-land, standards were developed for TV display. The 16/236 translates to the RGB values that are allowed. They appear in the Color Palette in PS (example below). These values can also be measured as IRE. Note: in Japan (also NTSC), deeper blacks were allowed in the standard, i.e. 7.5 to 100 IRE for others, and 0 to 100 for Japan. The IRE (Institute of Radio Engineers) regards the allowable luminance levels. There is even an Action in PS to "force" the luninance levels to NTSC Broadcast Safe (also below).

                     

                    Blacks_Whites_Video.jpg

                    Photoshop with both the white and the black color dialog screens open, plus the Actions Palette

                     

                     

                    When these RGB (or IRE) levels are viewed on a calibrated NTSC monitor, they appear as pure black and pure white. Now, with a non-calibrated monitor, things can appear all over the place. There is no control. If one is using an SD DVD-Video source and feeding that through an upscaling set-top player to an HD TV, even more bets are off. There is just no control over what will be displayed, as there are many ways that the player might handle things, plus there is no control over the calibration, or lack thereof, with the display device. This is what makes Video so maddening. Print work is so much easier to deal with and produce for.

                     

                    Good luck, and hope that this helps.

                     

                    Hunt

                    • 7. Re: True black on screen
                      the_wine_snob Level 9
                      Re Harm's comment that DPI does not matter.  I will need some convincing on that.

                       

                      In Video, it only matters with Height (in pixels) and Width (in pixels). All DPI info is thrown out. One cannot set the PPI of the TV. The TV does not care if the image was scanned at 1000 ppi, as it only displays pixels x pixels.

                       

                      Also, it does not matter if you have an image that's 40,000 pixels x 30,000 pixels (if PrPro could Import such), and use that in an SD/DVD-Video Project - all that can be displayed will be 720x480. In that mega-example one would have two choices:

                       

                      only see a 720x480 segment

                      resize down to 720x480*

                       

                      There are no other choices. The difference between the Standard, 4:3 vs Widescreen, 16:9 is with the Pixel Aspect Ratio, PAR - there are the same number of pixels. TV/Video is so much different than is print. When the Web started, and designers were suddenly faced with its limitations, they thought their world had ended. Man were they surprised when they moved onto Video as there are even more limitations!

                       

                      What you see in Photoshop is displayed on a high-rez progressive scan display that does care about PPI. That is set by your video card's driver console. When you display on a TV, all of that goes out the window.

                       

                      Hope that this helps,

                       

                      Hunt

                       

                      * one warning here. If one does do resizing to match their Project Preset, the best quality will come from doing that resizing in PS, as it has better algorithms, than does PrPro. Also, working with images that are approximately the Frame Size of the Project will lessen the resource load on the NLE program. This is one case where bigger is not better.

                      • 8. Re: True black on screen
                        Harm Millaard Level 7

                        Mark,

                         

                        Re Harm's comment that DPI does not matter.  I will need some convincing on that.  When I create a 1920 x 1080 image in photoshop and fill it with what i think is black, then type a word in the middle of the screen, add some effects, etc., and then ........

                         

                        ....if i do an image size to change this 1920 x 1080 image  from 72DPI to 300 DPI, the text appears much clearer on the screen which I assume will translate all the way down the line.

                         

                        ..... if I do an image size to change this 1920 x 1080 image from 72 DPI to 2 DPI, my text ends up looking like a pile of goo which i assume will translate all the way down the line.

                         

                        So,  to me it looks like DPI very much matters.  I know 300 DPI is overkill, but there must be some optimal DPI that I should be using for this type of image to be used in the video?


                        When I put an orange in the coffee machine, it does not come out as coffee. Weird, heh? When I put apple juice in my gas tank, my car does not start. Weird, heh?

                         

                        You are comparing apples to oranges. There is no setting for DPI in PR for the simple reason it is irrelevant.

                         

                        In PS you are mixing pixels (1920 x 1080) and DPI (300 or 72 or 2) for your text layer. It is incomparable.

                        • 9. Re: True black on screen
                          the_wine_snob Level 9

                          Mark,

                           

                          Here is an ARTICLE with discussion on NTSC luminance levels for broadcast, that I was searching for.

                           

                          Good luck,

                           

                          Hunt

                          • 10. Re: True black on screen
                            shooternz Level 6

                            In conjunction with all the good practical and technical advice you have been given...its simple enough to do a little test.

                             

                            Make an image and see if its black enough for you onre you have processed it in the NLE.

                             

                            BTW - you can use the scopes in PPro to see where your black "sits"

                            • 11. Re: True black on screen
                              k9tag Level 1

                              Ha, i knew I should have stayed out of Harm's way.

                               

                              I forgot to notice one little thing as i increased the dpi in photoshop - the image dimensions of course changed right along with the dpi so I no longer had my 1920 x 1080.  So.... I will stick with the default 72 dpi since it does not matter.

                               

                              Thx,

                               

                              -Mark

                              • 12. Re: True black on screen
                                Harm Millaard Level 7

                                No Harm intended.

                                • 13. Re: True black on screen
                                  Jim_Simon Level 8
                                  I want black to appear black onscreen rather than dark gray.

                                   

                                  That has little to do with your end.  The display needs to be properly calibrated.  Most aren't.