Sunday, August 17, 2008

On output sharpening

Lightroom 2.0 includes new output sharpening facilities in the export dialog, the print module and the web output module. These are extremely useful. The functionality is to correct for softness induced by the scaling for output and for the softness of the output medium such as a screen or a printing process. Here I'll talk about the use for output images for the web, email, etc. I used the export dialog scaled to 600 points for the long dimension and selected different levels of "screen" sharpening. Here is an example of a waterfall image. See (and buy prints of ;-) )the real image here. You can switch between different output sharpening levels by hovering over the names on top.


unsharpened

low sharpening

standard sharpening

high sharpening



To me, the difference between no sharpening and even just low sharpening is night and day. In the lychen details on the wet rocks for example. You wouldn't notice probably if you just have two images in different contexts, but you would probably thin-slice prefer the slightly sharpened one. The high sharpening is still very good in my opinion and works well for this image.

Here an another example of a cliché truck. This image has lots of sharp detail and you'll see that going to high has a different effect than on the waterfall image.

unsharpened
low sharpening

standard sharpening

high sharpening



Notice the extraordinary amount of extra detail that is pulled out in the hood area by the sharpening. This time, I think high is over the top and the best is probably low or standard. This is quite generally true for images that have man-made structures that have very sharp transitions. In general I have found that using standard gives very good results for most images, but of course this all depends on your taste.

5 comments:

  1. Dorin Nicolaescu-MusteaţăAugust 18, 2008 at 8:18 AM

    I don't know... I haven't fully "assimilated" it yet. Too much of what seems as artifacts to me.

    For example the rubber ribbon around the windshield. Being smooth in the unsharpened version, it slowly gets noticeable jaggies and artifacts around it.

    Also, the 'resize halo artifact' (like here http://www.flickr.com/photos/lagemaatphoto/2767370788/) discussed many times on the U2U forums, I can see them everywhere. And Adobe seem not to think it's something abnormal.

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  2. Dorin,

    you are right about the sharpening being too much on the car picture. I do think the low and standard look better. You're right about the resize artefact. That bugs me quite a bit too and I see it all the time, not only in my own pictures but also in other people's images on flickr. I can often tell immediately whether they use Lightroom.

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  3. Thanks for posting/sharing this!I found it very usefull and am now a bit more clever.

    (Didn't understand the thing about the artifacts though.)

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  4. What about printing? Do you find it useful for that as well. And what setting then, low or standard?

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  5. For printing it is very important indeed. I generally use medium there, but it really depends on the printer or lab that you use. This might sometimes also differ because of the actual image I guess even though the output sharpening is supposed to be independent of this. In the end whatever floats your boat is fine. Experimentation is key here again.

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