12 Replies Latest reply on Jul 30, 2015 12:05 PM by jerryp97433002

    Image Size

    jerryp97433002 Level 1

      I am working at understanding Image Size, Resolution, DPI, printing, uploading to the web, etc...in LR5. Getting there but still questioning myself at times.  There is so much written these days about not needing high pixel count cameras it poses some questions:

       

      1st Question: I have a Sony A7II (24MP) & there are 3 image sizes to choose from, S: 6.0M, M:10M, L:24M.   I know that one should always take photos at the cameras highest setting for re-sizing purposes later in post (LR5) for uploading to the web or printing, proper adjustments can be made, you can always take away but not add. I understand that web photos should be around 72 resolution & around 1400 pixels long side, prints at 300 resolution for best picture quality. If that's the case why choose S:6.0M or M:10M for photo's?  What scenario would be best for this camera setting? I'm guessing that it has to do with cropping, you would be able to crop a 24M and keep good resolution (at 72) but if you crop a 6M or 10M photo you could possibly loose to much resolution depending on how much you cropped thus leaving you with terrible image quality. Am I correct?

       

      2nd Question: Lets say I take a photo at 6M or 10M & processed it in LR5, no cropping done & want to upload it to the web, because it has a smaller pixel count (then a setting at 24M) would I still loose image quality because I selected 72 resolution & 1400 long side needed for web?

       

      I explained it the best way I could. I realize there are variables in all this, that's why its confusing at times. I've been taking real estate photos for my wife and some upload & work perfectly in the MLS website (Multiple Listing Service) while others have issues. Some are to large, I now know its to large of a file with to much resolution and it fills the screen way to much for viewing properly & some have to much noise, confused here & tying to sort it all out. I have been experimenting with smaller sizes (6M & 10M) but not working great, its possible I choose the wrong setting in post for uploading   not really sure anymore, like I said earlier to many variables. Any help here would be appreciated. I might not be able to respond to anyone's posts in the next few days so I apologize in advance but will when I am able. 

       

      Look forward to hearing your comments......jp

        • 1. Re: Image Size
          dj_paige Level 9

          I understand that web photos should be around 72 resolution

          Incorrect. The resolution is completely meaningless for web photos.

           

          around 1400 pixels long side

          maybe, it depends on a lot of things

           

          If that's the case why choose S:6.0M or M:10M for photo's?

          The only reasons I can think of is to save space on your camera card or hard disk; or if you need to send it via the internet immediately after capture, then smaller size photos can be sent more quickly

           

          2nd Question: Lets say I take a photo at 6M or 10M & processed it in LR5, no cropping done & want to upload it to the web, because it has a smaller pixel count (then a setting at 24M) would I still loose image quality because I selected 72 resolution & 1400 long side needed for web?

          The loss of quality is actually a loss of resolution when you capture the image. And so yes, assuming these are JPGs, the editing also could produce a loss of quality compared to the 24 MP version

           

          I explained it the best way I could. I realize there are variables in all this, that's why its confusing at times. I've been taking real estate photos for my wife and some upload & work perfectly in the MLS website (Multiple Listing Service) while others have issues. Some are to large, I now know its to large of a file with to much resolution and it fills the screen way to much for viewing properly & some have to much noise, confused here & tying to sort it all out.

          Most web sites (I don't really know about MLS) fit the image into a specified screen area, and so if the image is 1200x800 or 2400x1600 or 4800x3200, the same screen area would be filled. But it would take longer for users to see the larger images because more pixels have to be transferred to the user's computer.

          • 2. Re: Image Size
            jerryp97433002 Level 1

            Thank you for your input. I've read so many posts with different views it

            gets confusing. Most say 72 resolution is best for web posting or Facebook.

            I am looking for the best resolution (these are real estate photos) &

            correct size for viewing (opens without long lag time). I use a tripod for

            most of my shots so hand shake isn't an issue, as for cropping I usually

            don't have to do that, I can compose the photo when taken. If I do crop it

            is almost nothing, maybe something on the edge I captured by accident. I

            have experimented and uploaded some photos at 1400 long side & it opens

            nicely, big enough for viewing. So....my next question is:

             

            If I take the same photo at 24MB, 10MB, or 6MB & resize the photo during

            exporting from LR5 say 1400 long side & 300dpi, would all photos have the

            same quality or would I loose some quality due to resizing? I've read that

            for cropping purposes its best to take photos at the largest size cause you

            can always take away but can't add. So does the same go for resizing

            without cropping?

             

            jp

            • 3. Re: Image Size
              dj_paige Level 9

              Most say 72 resolution is best for web posting or Facebook.

              This resolution number is irrelevant. The image appears the same whether it is 7 or 700. If you don't believe me, try it yourself.

               

              If I take the same photo at 24MB, 10MB, or 6MB & resize the photo during exporting from LR5 say 1400 long side & 300dpi, would all photos have the same quality or would I loose some quality due to resizing?

              The quality changes because the original has captured different number of pixels, so the original quality is not the same. Then the process of exporting to a JPG also causes a loss of quality. None of the preceeding has anything to do with the 1400 long side. Then, quality loss can also happen depending on the 1400 long side (which would probably be higher quality than 1000 long side). The 300 ppi (not dpi) is irrelevant, it makes no difference to the quality of the exported image. The image appears the same whether it is 7ppi or 700ppi. If you don't believe me, try it yourself.

              I've read that for cropping purposes its best to take photos at the largest size cause you can always take away but can't add. So does the same go for resizing without cropping?

              If I understand the question, these are apples and oranges. You can't make any logical comparisons between cropping or not, and resizing. Or maybe I just don't understand the question.

              • 4. Re: Image Size
                Per Berntsen Adobe Community Professional

                You have a 24 MP camera, so you should take all your pictures at that size. You never know what you might need an image for in the future. Maybe someone will ask you for a big print, and all you have is a  6MP image ...

                 

                When you export an image and downsize it, you get a new image. It will have lost quality in the sense that if you make a 20x30" print from both of them, the small one will look terrible. But your intention is to publish it on the web, where it will look fine, provided it is properly processed and sharpened. Try Standard sharpening for screen in the Export dialog.

                 

                And forget about ppi as an indicator of quality. All that matters on the web is pixel dimensions.

                Ppi is metada that only comes into play when printing.

                • 5. Re: Image Size
                  jerryp97433002 Level 1

                  Thanks for your input, its starting to make some sense & getting some

                  perspective. I have experimented exporting the same image at different

                  resolution settings but could not see any difference in the quality of the

                  image, but have read that it does make a difference so I thought I'd get

                  some other perspectives on this topic. When I go to export a photo in LR5

                  under the Image Size tab you have 2 selections next to the resolution,

                  pixels per inch or pixels per cm (I choose ppi). If I download a photo

                  right from the memory card to my computer & click the properties of a photo

                  then go to the details tab it gives me the dpi for that photo. Sometimes

                  its 240, 300, or 350. Is this due to the size photo I selected to take?

                  (i.e 24MB, 10MB, 6MB)

                  jp

                  • 6. Re: Image Size
                    trshaner Adobe Community Professional & MVP

                    jerryp97433002 wrote:

                    When I go to export a photo in LR5

                    under the Image Size tab you have 2 selections next to the resolution,

                    pixels per inch or pixels per cm (I choose ppi).

                    jp

                    The LR Export module only uses the 'Resolution' entry field when 'Resize To Fit' is selected and a value in in or cm is selected. For all other Export operations the Resolution field is simply written to the file's EXIF metadata with no change to the actual image data. Very few applications actually use the EXIF Resolution field so it's value has no impact on the image quality.

                     

                    jerryp97433002 wrote:

                    If I download a photo

                    right from the memory card to my computer & click the properties of a photo

                    then go to the details tab it gives me the dpi for that photo. Sometimes

                    its 240, 300, or 350. Is this due to the size photo I selected to take?

                    (i.e 24MB, 10MB, 6MB)

                    jp

                    As already stated it doesn't really matter....Very few applications actually use the Resolution field data. Camera manufacturers feel obliged to enter some finite value into the EXIF Resolution field and most use 240 as a value that will produce high quality prints. If you are Exporting files to send to a print house ask them what the resolution should be. YOU will enter that value into the Export module along with the print dimensions.

                    • 7. Re: Image Size
                      jerryp97433002 Level 1

                      Thx, When would you choose the "Resize to Fit"? Right from the start mine

                      was already pre-selected.

                      jp

                      • 8. Re: Image Size
                        jerryp97433002 Level 1

                        Thank You for your input. As for your advise on using Standard Sharpening

                        for screen in the Export dialog (Low, Standard, High) I have always chosen

                        High thinking it would be best, is it possible that it could cause noise in

                        the photo?

                         

                         

                         

                         

                         

                         

                        On Sun, Jul 26, 2015 at 10:06 AM, Per Berntsen <forums_noreply@adobe.com>

                        • 9. Re: Image Size
                          dj_paige Level 9

                          jerryp97433002 wrote:

                           

                          Thx, When would you choose the "Resize to Fit"? Right from the start mine

                          was already pre-selected.

                          jp

                          You check "Resize to Fit" when you want to resize the photo. If you want to limit the photo to (for example) 1400 pixels on the long edge, then you must check "Resize to Fit".

                           

                          As for your advise on using Standard Sharpening for screen in the Export dialog (Low, Standard, High) I have always chosen High thinking it would be best, is it possible that it could cause noise in the photo?

                          You choose the option that will work best for you. Sometimes this is trial and error, and sometimes "High" sharpening will "over-sharpen" the image, giving it "halos" around edges. Please see How to Properly Sharpen Images in Lightroom for more details.

                          • 10. Re: Image Size
                            jerryp97433002 Level 1

                            Thanks for your advise, very helpfull, pieces are starting to come together....jp

                            • 11. Re: Image Size
                              ManiacJoe Adobe Community Professional

                              Not "cause" noise, but certainly show it to you or exaggerate it. Over sharpening is easy to do and not desirable.

                              Start with the "standard" setting. Adjust (up or down) from there as you need by looking at the results.

                              • 12. Re: Image Size
                                jerryp97433002 Level 1

                                Thanks for your comments, with the advise & support from all who answered

                                my questions I have a handle on it & heading in the right direction.....jp