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how to sharpen a photo taken at sunset?

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  • how to sharpen a photo taken at sunset?



    I really like this shot, it was taken just before the sun went down. it's obviously not sharp, but that's because of the colours (it's a pale yellow on a pale blue) imo. Is there any way I can get this sharp enough? Or is this just a nice shot for my personal collection?

  • #2
    I've never really heard of colour affecting sharpness but it looks like it should sharpen up fairly easily to me. Do the normal settings you use not work?
    Seeing the world with a 3:2 aspect ratio...

    My images on Flickr

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    • #3
      That surprises me. I always thought that was the reason the yellow/black danger signs were colored that way.

      This image is already sharpened more than I usually sharpen images. Should I just sharpen it even more? The cross on the side and the bottom of the fuselage are starting to look a little ugly to me.

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      • #4
        Yellow/black danger signs? I'm confused! Either way, colour doesn't really have anything to do with sharpness. You can remove all the colour information from a digital image and it won't affect the sharpness in any way.

        Is there any way you can post it unsharpened? There's no real way of being able to tell anything on an already sharpened image.

        Paul
        Seeing the world with a 3:2 aspect ratio...

        My images on Flickr

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        • #5
          sure

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          • #6
            about the yellow/black danger signs

            I am correct in assuming an image that is only black and white (no graytones) would not need sharpening, right?

            for what it's worth I get lots more "soft" rejections for images that lack a strong contrast (like this one)

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            • #7
              Originally posted by biggerben View Post
              about the yellow/black danger signs

              I am correct in assuming an image that is only black and white (no graytones) would not need sharpening, right?
              In theory no, but it doesn't quite work the same way in photography when it's very rare to have true white or black. And so, in this case, colour has nothing to do with sharpness.

              Paul
              Seeing the world with a 3:2 aspect ratio...

              My images on Flickr

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              • #8
                well, if you say so

                whatever the colour of the unsharpened image, do you think it's savable?

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                • #9
                  The version you posted is heavily compressed and the sky's pixelated. It's not possible to tell anything accurately from such a low quality image but this is about as sharp as that particular version will ever be, which to me isn't quite good enough. Again though, it has other flaws so it's impossible to tell.



                  Just for fun, if we remove the colour information the apparent sharpness is totally unchanged. We just see the compression more clearly.



                  This very low resolution version is almost acceptable in terms of sharpness (but very much not acceptable in terms of compression), so you may be able to get something from the original as long as you don't need to crop too much. Feel free to email me the original if you want a proper opinion on the 'full fat' version.

                  Paul
                  Seeing the world with a 3:2 aspect ratio...

                  My images on Flickr

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                  • #10
                    eek, silly me, I posted a rather big thumbnail, sorry about that :/
                    here would be the one scaled down to 1024px, how about this version?



                    when i was talking about black and white, I really did mean #000000 on #FFFFFF (therefore the no gray tones part), shots like this awesome one here http://www.jetphotos.net/viewphoto.p...6761557&nseq=2. This one probably didn't need heavy sharpening, right?
                    But doesn't really matter, I do have more trouble sharpening shots like this that don't have colours in strong contrast to each other. whether I should or not

                    sorry for posting the wrong version.

                    if you sharpen this one too, could you tell me if you used any special parameters (larger radius, larger amount, more passes ...?)

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                    • #11
                      I had a go at sharpening that one and used one pass of USM at 110%, 0.3 and then another at 40%, 0.3 and to me it looked borderline acceptable, so personally I'd probably vote add. You'd almost certainly get slightly cleaner results sharpening on the full size image first, resizing and applying a little more sharpening but I do think this can be made acceptable.

                      As for the Dash-8 image, it needed exactly the same amount of sharpening as any other image. The problem is you're assuming the boundary between the black fuselage and the orange sky is perfectly sharp because there are essentially only two colours, but in truth the colour has absolutely nothing to do with how sharp that boundary is. What sharpening essentially does is make the lines between areas of contrast (not colour) more defined (which is the reason you can't sharpen the line between a white fuselage and a cloudy sky sometimes if they blend into one - there's no line so there's nothing to actually sharpen). So, you say you have problems sharpening images that don't have strong colours but the actual problem isn't the lack of colour, it's a lack of contrast. Sharpening can only work well on an image that has good contrast, so getting that means nailing the exposure and ensuring you have the full range of tones in your image.

                      Sharpening is needed because digital as a medium is generally inherently quite soft, which is why almost all point and shoot cameras have built-in sharpening that can't be turned off. The sharpness of an image essentially depends how many pixels these lines between areas of contrast are spread over; the less pixels the sharper the image, and the more pixels the softer the image. If, for example you take a sharp photo of a plane and zoom in to look at the individual pixels, lines between things like the fuselage and the sky will probably be spread over 2 or 3 pixels, whereas on a blurred shot they may be spread over 4, 5, or more pixels which destroys the sharpness.

                      The examples here were for a slightly different subject, but basically I've zoomed in an an image that only has two colours; the blue of the sky and the white of the fuselage. You can see all the standard sharpening issues still exist, and you can also see that removing the colour wouldn't make any difference.

                      http://forums.jetphotos.net/showthread.php?t=49460

                      If we remove all the colour information those lines are still spread out over the same number of pixels so the sharpness is totally unaffected. Even if you shoot something like a bright red apple against a white sheet of paper so there are essentially only two colours, exactly the same applies. Colour has no real affect on the sharpness of digital images. It affects how you perceive things and you may think you're seeing a clearer image because the colours make certain parts stand out, but if you look at the actual sharpness you'll see it makes no difference.

                      I know the lines you're thinking along with this, it just isn't quite right!

                      Paul
                      Last edited by PMN; 2010-01-30, 12:04.
                      Seeing the world with a 3:2 aspect ratio...

                      My images on Flickr

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                      • #12
                        Originally posted by biggerben View Post
                        That surprises me. I always thought that was the reason the yellow/black danger signs were colored that way.

                        Interesting conflation here biggerben... hope this helps to put it all into context:

                        In theory, because sharpening depends upon increased contrast at "sharpened" edges, you have a point about colour being relevant.

                        However, as Paul notes, this isn't really a consideration in the sense of it having an overall effect on whether someone percieves an image to be sharper if it doesn't have coloured tones... unless they are dominant and at least at the sizes / resolutions used on the site / internet etc. (perhaps it would if we were talking about huge posters viewed close up).

                        FYI - the black / yellow combination is considered to give the most contrast in terms of visibility (I guess you could say that it is considered to be the "sharpest" combination) and is therefore more easily read than any other combination (hence nuumber plates as well as important signs etc.).

                        Why this is so is not completely clear (why not B&W?) but it is thought to at least have something to do with the way we percieve colour (i.e not so much our eyes, but our brains).

                        However, the black / yellow 'high viz status' does also obviously have a basis in the qualities of the combination and, in terms of the light spectrum, other scientifically validated high contrast combinations are, for example: Red / Cyan, Blue / Yellow, Green / Magenta.

                        This is because they are directly opposite in the spectrum and , in that sense, if you take a negative of an image you will see the highest contrast colours of the positive image.


                        Paul
                        Last edited by HB-IHC; 2010-01-30, 13:04.



                        All our final decisions are made in a state of mind that is not going to last (Marcel Proust)

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                        • #13
                          The very best I could come up with was this. Workflow was....

                          1. Slight adjustment of highlight end of histogram.
                          2. 10 x passes of USM at 50_0.2_0
                          3. +18 of contrast.

                          ....but it's still compressed, especially at the front end and the fin.

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

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                          • #14
                            wow, that's amazing sharp!

                            I've never done more than 2 passes with the USM, maybe it's time I tried some other ways

                            Thanks Brian + Paul!

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