Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: NigelC on August 03, 2010, 06:24:12 am
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Just wondered if anyone has experience of this. Alamy upload instructions say files should not have any sharpening, but I wonder if they mean output sharpening. Many people would apply some sharpening in a raw converter to compensate for AA filter softening, prior to import into Photoshop. I will try myself, but if a file is rejected by Alamy, I'm not sure you would be able to isolate presence of "input" sharpening as the reason.
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Instructions by Alamy are contradictory. In one place they say you must not sharpen (at all). In another place of their instruction they say you must be careful not to oversharpen images.
In Alamy forum there are two schools of thought active: one says to never sharpen, the other says to apply a moderate "capture sharpening".
I myself do apply a bit of sharpening to my images (I always start from RAW) and I consistently pass QC at Alamy. You really have to apply a sharpening which is barely noticeable when seeing the image at 100% magnification. Either you apply a very small sharpening at the RAW conversion stage, or you apply some subtle sharpening after the upsizing to 48 MB, if you still do it (it is not compulsory any more).
Provided the sharpening is a very subtle one, it will do no harm and actually it will help in passing Alamy QC.
To give you an idea of how small the sharpening should be:
If I do it in Lightroom, during RAW conversion, I apply amount 12, radius 1, detail 25, mask 58.
If I do it in Photoshop I use Smart Sharpen, with "20%, 1 pixel, reduce Lens blur, more accurate".
I have a 10 mp camera. With those values you should be safe. I repeat the effect will be subtle, but present anyway. If the image is not properly sharp on its own, "sharpening" it will not improve it, but if it is sharp, "sharpening" it will improve it.
Good luck with QC
Fabrizio
EDIT Using "smart sharpen" with "reduce lens blur" means also appling some deconvolution, not only sharpening in its traditional meaning. I find it works well.
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Instructions by Alamy are contradictory. In one place they say you must not sharpen (at all). In another place of their instruction they say you must be careful not to oversharpen images.
In Alamy forum there are two schools of thought active: one says to never sharpen, the other says to apply a moderate "capture sharpening".
I myself do apply a bit of sharpening to my images (I always start from RAW) and I consistently pass QC at Alamy. You really have to apply a sharpening which is barely noticeable when seeing the image at 100% magnification. Either you apply a very small sharpening at the RAW conversion stage, or you apply some subtle sharpening after the upsizing to 48 MB, if you still do it (it is not compulsory any more).
Provided the sharpening is a very subtle one, it will do no harm and actually it will help in passing Alamy QC.
To give you an idea of how small the sharpening should be:
If I do it in Lightroom, during RAW conversion, I apply amount 12, radius 1, detail 25, mask 58.
If I do it in Photoshop I use Smart Sharpen, with "20%, 1 pixel, reduce Lens blur, more accurate".
I have a 10 mp camera. With those values you should be safe. I repeat the effect will be subtle, but present anyway. If the image is not properly sharp on its own, "sharpening" it will not improve it, but if it is sharp, "sharpening" it will improve it.
Thanks, very useful
Good luck with QC
Fabrizio
EDIT Using "smart sharpen" with "reduce lens blur" means also appling some deconvolution, not only sharpening in its traditional meaning. I find it works well.