21 Replies Latest reply on Oct 1, 2016 12:00 PM by johnty52

    Image size in Develop Module vs Explorer

    meltdownman

      I am taking a 17 megabyte DNG file in LR CC and exporting to either NIK software or PS CC for editing. I have set up the external edit preferences as follows:
      Export as TIF, ADOBE 1998 RGB, 600 pixels.  When I go to save the file in either NIK Software or PS CC the file size gets reduced to a 5 megabyte file which is unacceptable for printing (e.g. the graininess from the image gets exaggerated).  The graininess was okay in the 17 megabyte LR DNG file but the 5 megabyte files become unusable.

       

      Someone asked if the same thing is happening if I go into PS CC and save it as a PSD file:

       

      So I worked the image originally as a DNG file and exported it to PS CC and made some minor changes as suggested and this is what I found:

       

      WhenI go and open a particular photo in LR and hit the "I" key for information it shows a megapixel of only 2.8 megapixels (psd).  When I go to view the same image by selecting "show in Explorer - I am using a PC) and right click for properties the megapixels show up as 36 megapixels (psd).  Someone in a forum stated that LR might be pointed to the wrong file but I don't understand why this would be the case since there is only one file.  Could LR be pointing to a "preview" version of the photo vice the original file somehow?  Why would LR show me in the Develop or Library module a reduced size and then when I go and look at where LR says the photo is located in Explorer it is showing me a much larger file size?

       

      This is driving me insane.

       

      Thanks in advance.

       

       

        • 1. Re: Image size in Develop Module vs Explorer
          Per Berntsen Adobe Community Professional

          Don't use file size in MB as an indicator of image quality - it's in most cases unreliable and misleading.

          The important numbers are the pixel dimensions, or the megapixel count, which is the product of width pixels and height pixels.

          (6000 x 4000 pixels = 24 million pixels = 24 megapixels)

           

          So what are the pixel dimensions of the 17 mb DNG, and what are the pixel dimensions of the exported tiff?

          I'm guessing that you saved as jpg in Photoshop - what quality setting did you use?

          • 2. Re: Image size in Develop Module vs Explorer
            meltdownman Level 1

            The dimensions of the photo when I select the image in Explorer and open it up in PS CC is as follows:

             

            Image/file size: 15.8 M

            Dimensions 1916 x1437

            Fit to: Original Size

            Width: 1926

            Height: 1437

            Resolution: 360 Pixels/Inch

            Resample: Automatic

            • 3. Re: Image size in Develop Module vs Explorer
              meltdownman Level 1

              The dimensions of the photo in LR CC:

               

              Dimensions 1916 x1437

              File size: 2.8 M

              • 4. Re: Image size in Develop Module vs Explorer
                meltdownman Level 1

                Both the above are PSD files

                • 5. Re: Image size in Develop Module vs Explorer
                  meltdownman Level 1

                  When going to view the image in Explorer by right clicking on the image it shows 36.8 M for a PSD file. 

                  • 6. Re: Image size in Develop Module vs Explorer
                    meltdownman Level 1

                    Editing with 16 bit

                    • 7. Re: Image size in Develop Module vs Explorer
                      dj_paige Level 9

                      As Per stated above, you are looking at the wrong information. The file size does not tell you useful information about the photos.

                       

                      As long as you have the same number of pixels, then you can assume nothing is wrong.

                      • 8. Re: Image size in Develop Module vs Explorer
                        Per Berntsen Adobe Community Professional

                        I'm not entirely sure what you did, but here's a guess:

                         

                        • You cropped the image in Lightroom to 1916 x 1437 pixels.
                        • Then you exported that file as a tiff at 1916 x1437 pixels in 16-bit. The file size of this tiff is 15.8 megabytes, which is normal.
                        • You then saved a jpg from the tiff, which is 2.8 megabytes, which is also normal, jpg uses compression to reduce file size, and it's 8-bit only.
                        • Then you checked the file size of the original DNG in Windows Explorer, and it was 36.8 megabytes. This is also perfectly normal, because Explorer knows nothing about edits you have done in Lightroom, including cropping.

                         

                        As for the graininess - please post screenshots of both images at 1:1 (100%), as welll as a screenshot of the Detail panel in Lightroom.

                        • 11. Re: Image size in Develop Module vs Explorer
                          meltdownman Level 1

                          I'm not entirely sure what you did, but here's a guess:

                           

                          • You cropped the image in Lightroom to 1916 x 1437 pixels.
                          • Then you exported that file as a tiff at 1916 x1437 pixels in 16-bit. The file size of this tiff is 15.8 megabytes, which is normal.
                          • You then saved a jpg from the tiff, which is 2.8 megabytes, which is also normal, jpg uses compression to reduce file size, and it's 8-bit only.
                          • Then you checked the file size of the original DNG in Windows Explorer, and it was 36.8 megabytes. This is also perfectly normal, because Explorer knows nothing about edits you have done in Lightroom, including cropping.

                           

                          As for the graininess - please post screenshots of both images at 1:1 (100%), as welll as a screenshot of the Detail panel in Lightroom.

                           

                          Bern:

                           

                          This is exactly what I did.  I never knew that the JPEG's were rendered in 8 bit. So is the fact that they are going from 16 bit to 8 bit the reason for the file size reduction? 

                           

                          I am sending out images for print for the very first time and that is how I discovered the dramatic change in file sizes.

                           

                          If this is the case, since some printing businesses that I send my images to via the internet only take JPEGs should I be sending my images to those companies that also accept TIFF files to maximize the quality/color spectrum of my images and also reduce the amount of grain showing up in my images (i.e. are TIFF's converted to 8 bit)?

                           

                           

                          A couple of other questions:

                           

                          1) On the other issues with regards to sending images to printers, should I be using the setting of Pro Photo...the pop up menu in LR CC suggests that I do that in the Preferences menu.

                           

                          2) My workflow typically has me start out in LR CC.  When working between LR CC and Photoshop CC should I be sending files back from PS CC as TIFF files to maintain as much resolution as possible?

                           

                          I really appreciate you clearing this issue up for me.  I noticed that a lot of other people in other forums are getting frustrated by not understanding the compression that was going on with JPEG files.

                           

                          Stephen Carolin

                           

                           

                           

                          • 12. Re: Image size in Develop Module vs Explorer
                            Per Berntsen Adobe Community Professional

                            The two screenshots are of the same image (and the first one is too small).

                            Please post a screenshot of the DNG at 1:1, including the Detail panel.

                            And - did you use output sharpening on export?

                            • 13. Re: Image size in Develop Module vs Explorer
                              Per Berntsen Adobe Community Professional

                              Going from 16-bit to 8-bit halves the file size.

                              In addition jpg uses compression to reduce the file size (that's the whole point of using jpg).

                              I suggest that you take a look at some articles I wrote - What is a digital image? and File formats

                              Lightroom basics could also be useful.

                              I'll be happy to answer your other questions, but it's getting very late, so I'll get back to you tomorrow, or maybe somebody else will answer them in the meantime.

                              • 14. Re: Image size in Develop Module vs Explorer
                                meltdownman Level 1

                                I don't have the original DNG file. This is of a picture I took years ago.  With regards to "Sharpening on Export" I did have the default set to that setting.

                                 

                                Stephen

                                • 15. Re: Image size in Develop Module vs Explorer
                                  meltdownman Level 1

                                  Thanks for everyone's time.  I really do appreciate it. 

                                   

                                  I will take a look a the file formats.  I guess what had concerned me was the fact that going from 16 bit TIFF to 8 bit JPEG was much more than cutting the file size in half (i.e. 17 megs TIFF to 2.8 megs JPEG).

                                   

                                  Stephen

                                  • 16. Re: Image size in Develop Module vs Explorer
                                    Per Berntsen Adobe Community Professional
                                    I guess what had concerned me was the fact that going from 16 bit TIFF to 8 bit JPEG was much more than cutting the file size in half (i.e. 17 megs TIFF to 2.8 megs JPEG).

                                    I just realized that you did not create a jpg (at least that's not what you posted screenshots of) but a PSD. And it's not 2.8 megabytes, but 2.8 megapixels (MP). Megapixels is the pixel count in an image (see post #1) - megabytes is file size.

                                    Again, I urge you to read What is a digital image?

                                    Understanding the difference between those two is absolutely necessary when dealing with digital images.

                                     

                                    I don't have the original DNG file. This is of a picture I took years ago.  With regards to "Sharpening on Export" I did have the default set to that setting.

                                    According to your original post, your source file in Lightroom. is a DNG.

                                    If that isn't the case, what kind of file are you starting out with?

                                    To be able to see the grain problem, you to have post screenshots of the original (whatever file that is) at 1:1, including the detail panel, and the exported file (that has become more grainy), also at 1:1.

                                    So far, you have only posted one screenshot that is truly 1:1, and it's unclear whether that's the original, or the exported image imported back into Lightroom.

                                    As for output sharpening, I don't know what the default setting is. If you choose Export in LR again, it should still be on the setting you used last. Did you export, or did you use Edit in Photoshop? If you used Edit in PS, no sharpening is added, except for any sharpening you have applied in Develop.

                                     

                                    I am sending out images for print for the very first time and that is how I discovered the dramatic change in file sizes.

                                    What you should be concerned about is the pixel dimensions, and what print size they will allow without enlargement.

                                    This image will print at 6.387 x 4.79 inches at 300 ppi. (divide pixel dimensions with 300 to get dimensions in inches)

                                     

                                     

                                    If this is the case, since some printing businesses that I send my images to via the internet only take JPEGs should I be sending my images to those companies that also accept TIFF files to maximize the quality/color spectrum of my images and also reduce the amount of grain showing up in my images (i.e. are TIFF's converted to 8 bit)?

                                     

                                    Most images will print fine from a maximum quality jpg, but there are cases when a TIFF will print better. If you want to be on the safe side, use TIFF. Send 8-bit files to the printer, but always edit in 16-bit, and convert to 8-bit as the last step. Do that on a duplicate, then you'll still have the 16-bit file if you want to edit it further.

                                     

                                    1) On the other issues with regards to sending images to printers, should I be using the setting of Pro Photo...the pop up menu in LR CC suggests that I do that in the Preferences menu.

                                    Most printers want files in the sRGB color space, some might use Adobe RGB. Find out what they want.

                                    You can edit in ProPhoto, but the file you send to the printer should be sRGB or Adobe RGB.

                                     

                                    2) My workflow typically has me start out in LR CC.  When working between LR CC and Photoshop CC should I be sending files back from PS CC as TIFF files to maintain as much resolution as possible?

                                    Yes, use 16-bit TIFF.

                                    • 17. Re: Image size in Develop Module vs Explorer
                                      meltdownman Level 1

                                       

                                      Here is the original DNG.  I did not have this with me when I was writing to the forum (on  a different computer).

                                      • 18. Re: Image size in Develop Module vs Explorer
                                        meltdownman Level 1

                                         

                                        When I go into the print module it says that I can print 10 x 8 with the settings of 300 DPI.

                                        • 19. Re: Image size in Develop Module vs Explorer
                                          meltdownman Level 1

                                          From the book "Adobe Photoshop Lightroom CC/6 The Missing FAQ's" Ms. Victoria Bampton states that you can turn on 16 bit printing (page 424) though I can't seem to find that setting.

                                           

                                          The other thing is that she says that if  you want to remove a few of the variables and let a photographic lab handle the printing for you,  you can save your layout as a JPEG format  and use the standard Export Dialog instead.  Do you agree with this?

                                          • 20. Re: Image size in Develop Module vs Explorer
                                            Per Berntsen Adobe Community Professional
                                            Victoria Bampton states that you can turn on 16 bit printing (page 424) though I can't seem to find that setting.

                                            I never print from Lightroom, but 16-bit printing is apparently only available on Mac, and only for certain high-end printers.

                                            And I have never seen a print from a 16-bit file compared to one from an 8-bit file, so don't know how much there is to gain in quality.

                                             

                                            you can save your layout as a JPEG format  and use the standard Export Dialog instead.  Do you agree with this?

                                            I do my own printing, but if I were to send off a file for printing, that's what I'd do, yes.

                                             

                                            When I go into the print module it says that I can print 10 x 8 with the settings of 300 DPI.

                                            Since it turns out that the DNG is 21 megapixels, of course you can.

                                            But stop using megapixels, set LR to display pixel dimensions instead.

                                            Then do the math, as I explained in post #16.

                                             

                                            If you still want help with the graininess, you have to post screenshots of the two images at 1:1, with the Navigator on the left and the Detail panel on the right visible. Post the screenshots at full size, do not downscale them. See example below.

                                            Sharpening and noise reduction should always be done at 1:1 view - any other view will be inaccurate and misleading because of image scaling.

                                            Lr-1-1-detail.png

                                            • 21. Re: Image size in Develop Module vs Explorer
                                              johnty52

                                              I think I just made the same mistake as you 'meltdown'. I wanted to see the image's file size on disc in the grid view and chose the MP info display - took me an hour to realise what i had (not) done 

                                               

                                              I'd misread -  thought it gave me the file size in Mbytes on the disc but it doesnt, it only gives MPixels,.

                                              So in your example 1926 x 1437 = 2767662 pixels = 2.8 Mpixels   (2.8 million pixels)

                                               

                                              Each pixel needs 3 bytes of colour information (for normal RGB),  and each byte contains 8 bits ("8 bits per channel" in PS)  hence the

                                              'colour depth' of 24 bit. ( 3 x 8 ) ,for 16.7 million colours.

                                              Approximate File size on the hard disc is then 2.8Mpx  x 3  bytes = 8.4 Mbytes for an uncompressed file.

                                              Saving as eg jpg will reduce that to say 5-30% and TIF (as per DNG) will reduce to about 60-80%  depending on quality.

                                              Main point, I couldn't find a way to tag my slides in library with their file size in Mbytes even though it is in the metadata.