10 Replies Latest reply on Jan 28, 2015 5:25 AM by ashleyp1563

    Why are my Jpg files so small after being saved from Nef

    ashleyp1563

      Hi,

      I am finally posting after months of trying to figure out why my images are saving so small, some 4mb after converting from Nef to Jpg.

      I am shooting with a Nikon D4s and came from a D800. I was spoilt with really large file sizes and now I am freaking out because my jpegs are so small.

      I am checking all the right boxes as far as I can see to save the jpg as large as I can, and I am not cropping the images before saving as Jpg.

      Has anyone else had this problem? I can't understand why a camera as amazing as the D4s is giving me such small files. I have read everywhere that my files need to be over 6mb to be classed as high res.

      The only thing that I can think of is maybe I am pushing my nefs too hard in camera raw/lightroom resulting in a loss of quality? Although my exposure is correct 90% of the time so Im only playing with highlights or luminance.

      Can anyone walk me through the process of what I should be doing so I can end this headache!

      Thanks in advance!

        • 1. Re: Why are my Jpg files so small after being saved from Nef
          JimHess Adobe Community Professional & MVP

          It could have to do with the contents of the image. Some images compress more than others just because of the content. I agree that 4 MB seems to be rather small from that camera. Are the JPEG images consistently that small? What are you using to create the JPEG files? Camera Raw or Photoshop?

          • 2. Re: Why are my Jpg files so small after being saved from Nef
            D Fosse Adobe Community Professional & MVP

            The D4s has a considerably lower resolution sensor - 4928 x 3280 versus 7360 x 4912 in the D800. That's 16 megapixels vs. 36.

             

            That jpeg size seems about right to me. I made some tests saving out jpegs at that pixel size, and got between 2 - 5 MB.

             

            What you get in return is a camera body built like a tank. It'll survive earthquakes, wars and minor planet collisions .

             

            If it's any consolation I work with a D800 and my experience is that the full "resolution potential" is extremely seldom reached. For that you need a heavy tripod, mirror lock-up, cable release, live view focusing, and a very, very few select top-rate lenses. Of my lenses only the micro 60mm/2.8 and the 85mm/1.8 qualify. And even so, the plane of critical focus is so shallow and paper-thin, even at small apertures, that this also limits the usefulness.

             

            Just to put it in perspective, I've seen motion blur with an 85mm lens at 1/250 sec. I've seen motion blur using telephotos with studio flash units (longer discharge times than portable flash).

            • 3. Re: Why are my Jpg files so small after being saved from Nef
              ashleyp1563 Level 1

              For example, this image is 4.2mb at the highest resolution I can get out of camera raw in Photoshop CC from the D4s

              Lagen by Ashley Paton PhotographyDSC_6218 TEST.jpg

              Compared to this image which is 8.8mb from the D800

              Thomas by AshleyPatonPhotography_ASH2306 test.jpg

              I've had to resize both these images to 900x wide to upload for demonstration purposes.

              This one is 3.5mb which is ridiculous! (from the D4s unedited)

              Kat by AshleyPatonPhotographyDSC_7352 test.jpg

              The way I am converting my Nefs to jpeg is by opening them in camera raw, or lightroom depending on whether I'm doing a lot of images at once.. and then clicking save as, jpeg, and then hitting 12 for maximum quality.

               

              So upsetting, and embarrassing that I can't figure this out. I've never had an issue like this before and surely a flagship camera can produce higher res images. I appreciate the sensor size is considerably smaller than the D800 but I at least expect consistent 6mb images from the studio sessions. They will look terrible printed large right?

               

              Thanks for your help!

              • 4. Re: Why are my Jpg files so small after being saved from Nef
                Yammer Level 4

                I'm a little confused by your description. You are measuring a camera's files by the size of its JPEGs? That's not a very scientific way of doing things.

                 

                JPEG file size varies a lot with compression and content. I'm not surprised that a low-key B&W photo comes out small, as JPEG compression will remove a lot of black from the data. That's the whole point of JPEG: efficient use of storage/transmission bandwidth.

                 

                What you haven't stated specifically is that your JPEG files are 16MP (4928 x 3280 px). Is this the case, just to put my mind at rest?  If you open a JPEG in Photoshop, the Info panel should declare a doc file size of about 48MB.  This is the uncompressed file size.

                 

                Logic dictates that a 16MP camera will (on average) produce an equivalent JPEG of 44% the size of that of a 36MP camera, assuming that similar processing settings are being used. If you are using less sharpening or more noise reduction, then JPEG sizes will be smaller. If the finished image is downsampled, it will definitely be smaller.

                • 5. Re: Why are my Jpg files so small after being saved from Nef
                  Yammer Level 4

                  I just tried a Panasonic GX1 image, which is 16MP.

                   

                  I took an image with a lot of detail and processed it like I normally would.

                   

                  acr.jpg

                  I saved it as JPEG with 12 quality and it came out at 10.6MB.

                   

                  I then converted it to B&W, increased Clarity (as I normally would for B&W), and gave it a heavy Vignette (to simulate a low-key shot).

                   

                  bandw.jpg

                   

                  Again, I saved it at 12 quality. It came out at 3MB.

                  • 6. Re: Why are my Jpg files so small after being saved from Nef
                    ashleyp1563 Level 1

                    Sorry, you're quite right it wasn't a very scientific description. I am hopelessly bad at explaining what I mean and this is the first time I've ever posted in a forum so bear with me.

                     

                    Images are 16pm (4928x3280px as you say), and the doc is 48mb.

                     

                    So here's where I really show myself up... am I right in assuming that the more adobe compresses an image the lower the mb is on the final file, meaning if there is less detail (i.e. the low-key image is predominately black) then the jpeg will be smaller. Does this affect the print quality?

                    4mb seems very low res to me. How can I retain as much of the information as possible? Do you think I should sharpen more to retain detail? Or does it even matter and I'm fretting over nothing!

                    Thank you.

                    • 7. Re: Why are my Jpg files so small after being saved from Nef
                      D Fosse Adobe Community Professional & MVP

                      Jpeg file compression is independent of resolution. It's a data compression algorithm (and destructive, irreversible and cumulative at that. But highly effective). The resolution however stays the same so you have the same amount of detail, as long as the compression doesn't introduce too many artifacts.

                      • 8. Re: Why are my Jpg files so small after being saved from Nef
                        ashleyp1563 Level 1

                        Thanks twenty_one. That's answered my question

                        • 9. Re: Why are my Jpg files so small after being saved from Nef
                          Yammer Level 4

                          ashleyp1563 wrote:

                           

                          Images are 16pm (4928x3280px as you say), and the doc is 48mb.

                           

                          So here's where I really show myself up... am I right in assuming that the more adobe compresses an image the lower the mb is on the final file, meaning if there is less detail (i.e. the low-key image is predominately black) then the jpeg will be smaller. Does this affect the print quality?

                          4mb seems very low res to me. How can I retain as much of the information as possible? Do you think I should sharpen more to retain detail? Or does it even matter and I'm fretting over nothing!

                          Okay. The file dimensions are fine, so we're talking purely about content and compression.

                           

                          As I already said, the low-key image contains very little data in the first place (lots of black and no colour), so it compresses well.  The dreamy woman image contains a lot of plain blue sky and out-of-focus background, so that compresses well too. No surprises there.

                           

                          Have you got any more detailed images with greater depth of field? Try creating a JPEG of that and see how big the file is.

                           

                          An Adobe JPEG Quality setting of 12 means minimum compression and therefore maximum file size. But, even so, if you saved an image which was just a single plain colour, you would find that the resulting JPEG would be just a few kB. This is how compression works.

                           

                          The lower the quality number is set, the higher the compression, the more detail is lost, and the more JPEG artefacts are created in the image.  You are already saving at 12 quality, which is the highest setting, so you are minimising any problems with detail. You should save as TIFF if you want absolutely no loss of detail, but the file sizes are much bigger.

                           

                          4MB is not a resolution. Think of it as packing a suitcase. If you're taking lots of books, you won't get the lid down. If you're taking lots of soft woollen sweaters, you can take lots. 4MB is an indication of the space that your packed image takes—if it's made of light fluffy stuff then it will be a smaller suitcase! :-)

                           

                          You should sharpen your images the same as any other. Large areas of plain or out-of-focus background need not be sharpened. You're okay. Stop worrying!

                          • 10. Re: Why are my Jpg files so small after being saved from Nef
                            ashleyp1563 Level 1

                            That's great. Thanks for explaining it for me!