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  • Under-sharpened Rejections

    My last batch of photos seemed to get quite a few under-sharpened/soft rejections. in my personal opinion, they were all perfectly sharpened, but the screener thought otherwise. I was wondering if there's a guideline to go by that tells me when to stop sharpening the pic.

    Any help is much appreciated.

    -Chris

  • #2
    Hard to give you feedback without seeing the photos in question Chris, but as a rule of thumb you'll want to get the shot looking as crisp as possible. You'll usually find the time to stop occurs when you start seeing jaggy lines on vertical lines and titles become jaggy and start to show artefacts. There is no set way of sharpening a shot to perfection as each photo from a different camera comes out at varying stages of sharpness and will need editing accordingly. Best bet is to follow a work flow and find out which overall settings work best for shots from your camera. These settings will of course need tweaking slightly from photo to photo, but overall you should have a idea of how much sharpening is needed on each photo and how to go about it. For me its two or three passes of USM at 100% 0.2 and 0.0 threshold.

    Comment


    • #3
      Oversharpened is one of the most common causes of rejection. It often occurs as a result of trying to sharpen a blurry, out of focus picture which is never going to be salvageable. Other times it is the result of simply what the rejection says, i.e. it has been sharpened too much to the point that disagreeable artefacts have been introduced.

      All digital pictures generally need some degree of sharpening. I say generally but there are a few that are perfect straight out of the camera. In my case, out of 900+ pics in the database I can count on the fingers of one hand how many of my pics did not need sharpening....and still have two fingers left to rudely tell someone to go away !!

      So, how do you recognise oversharpening ?

      This first pic is an example of one of mine that didn't need any sharpness processing as far as I remember.....




      This second version has been further sharpened with four passes overall of 100_0.2_0 of USM. See how the Air Malta title on the fuselage and the Maltese Cross on the engine are getting a bit jagged on the edges. The cheat stripes on the fuselage also have a white outline to them. These are examples of when sharpening is getting to the edge of unacceptable.




      Now we'll go into the unacceptable area. This next picture has had another four overall passes of 100_0.2_0 USM. I have also selectively sharpened the Maltese Cross on the engine with yet another four passes of 100_0.2_0 of USM. See how every line in the picture that is not horizontal is jagged and how the Maltese Cross is also very grainy and blurred. Horizontal or vertical straight lines will not show "jaggies" but will have a big time white outline to them as can be seen on the horizontal cheat lines.




      So, how can we avoid these pitfalls ?

      Well, a properly focussed and exposed image to start with helps but generally we need to give even a good one a bit of a helping hand !

      I always start with 100_0.2_0 as my USM setting. It allows me to gradually add sharpness in small increments rather than going for one big smack of sharpening and risking going over the top at the first attempt.
      As soon as any of the above described artefacts appear I go back one step by hitting Ctrl+Z.

      I now have two choices.

      If further sharpening is required overall with just one small area becoming oversharp then I can create a background layer and sharpen overall to an acceptable level. I then use the eraser tool to "rub out" the now oversharp small portion of the the picture and flatten the image.

      If I only need to further sharpen small parts of the image then I can use the Lasso tool to select those areas and apply sharpening as required. You can go one pass more than required and use Ctl+Z to go back one step. Note that you can only go back one step using Ctrl+Z. If you go more than one step past what you want then guess what ?

      You got it, back to the very beginning. DO NOT be tempted to save as you go. This will risk introducing compression artefacts.

      I think that the best advice to give here is that if you can get a properly exposed, well focussed image at the beginning then you are 90% there. It may sound like personal trumpet blowing but I've only had a handful of rejections from my last 100 or so uploads because I've been out practising with exposure and focus and have not bothered to upload those pics that started to need more than a few minutes to process.

      I know, because I started out with this attitude, that photogs initially want to get their stats up by getting as many pics in the database as possible.

      After all, numbers mean success don't they ?

      Yes, to a degree that is true....but if getting 100 in means 200 rejects then maybe it's possibly not quite a success ?

      My personal pleasure these days is uploading a picture that I know is going to be accepted because it's a good picture.
      If it 'ain't broken........ Don't try to mend it !

      Comment


      • #4
        Thanks guys, that really helps me alot!

        Sorry Dan, I forgot to post the links. Here they are:
        http://www.jetphotos.net/viewreject_b.php?id=1860572
        http://www.jetphotos.net/viewreject_b.php?id=1857473

        There was another one I think but I can't find the link.

        Thanks again guys!

        -Chris

        Comment


        • #5
          For the Southwest...

          This I gave....
          2 x passes of 100_0.2_0 overall.

          Create a background layer

          2 x passes of 100_0.2_0 and then rub out the jagged wing leading edge. Flatten the image.

          Using the lasso tool, select the front door and cockpit area and give 2 x passes again of 100_0.2_0



          Compare with your reject, especially around the windows and registration.


          If it 'ain't broken........ Don't try to mend it !

          Comment


          • #6
            Thanks guys, this thread has been very helpful. I get quite a few of these rejections. I have a photo that I am wondering about: I apologize for already adding it to the queue.

            http://www.jetphotos.net/viewqueued_b.php?id=1865077

            Thanks in advance
            Will C.

            Comment


            • #7
              Originally posted by brianw999
              For the Southwest...

              This I gave....
              2 x passes of 100_0.2_0 overall.

              Create a background layer

              2 x passes of 100_0.2_0 and then rub out the jagged wing leading edge. Flatten the image.

              Using the lasso tool, select the front door and cockpit area and give 2 x passes again of 100_0.2_0



              Compare with your reject, especially around the windows and registration.


              I am relatively new to post processing other than the basic levels etc. But with the sharpening you mention 2 x passes of 100_0.2_0. What is that exactly? I use the Unsharp mask in PS I have seen there you have a percentage slide, is this what you are referring to?

              Carl

              Comment


              • #8
                He's refering to all three fields in the Unsharpen mask tool. First value (100) is the pecentage value, the second one is the Radius (0.2) and the third one is the Threshold (0).

                Comment


                • #9
                  Hi Degi,

                  Thought that might have been it, when referring to making 2 or 4 passes, I presume this means applying the same 2 or 4 times over?

                  I have tried these settings on a couple of photos tonight, much nicer finish.

                  cheers
                  Carl

                  Comment


                  • #10
                    Originally posted by cf73
                    Thought that might have been it, when referring to making 2 or 4 passes, I presume this means applying the same 2 or 4 times over?
                    Yes.

                    Comment


                    • #11
                      There is also quite alot of "noise" on the underside of the fuselage on the SW shot.

                      Comment


                      • #12
                        I think I need some new spectacles or even go to a good hospital to get my eyes lasered

                        Looking at the pics of the AirMalta from Brian; the second one looks 100% ok to me.
                        But he sais this one is a little bit oversharpened.There are some jegged edges/lines on the titles and the fuselage-lines.I don't see them at all , and that is very often the case when you call pics a little oversharpend.
                        Even on different monitors do pics often look perfect to me, when screeners say that they are oversharpened.

                        What's wrong with me?
                        Am i not looking at the right places or do my eyes become worser?

                        HELP ME.

                        regards,

                        Freek

                        Comment


                        • #13
                          The second one is noticably more sharpened, especially the Air Malta logo.

                          Comment


                          • #14
                            Freek,

                            When you are looking for jaggies, start by looking at the titles, the registrations, and on any line in the image. Once there are definate jaggies then you know that you need to go back one pass of the sharpening. Zooming in can also help you identify jaggies. If you are still in doubt post your pic in the Pre-Screening thread.

                            Cheers!

                            -Chris

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