keoj
Established
One of the great mysteries to me in PS is the unsharp mask settings. I would like to hear from others on what settings they use. For me, I use the following...
Scan at 4000 ppi - 16 bit - TIFF
Neat Image
Unsharp Mask at Amount = 100, Radius = 1.8, Threshold = 8
I only do one pass at USM but I have heard of some very exotic settings.
keoj
Scan at 4000 ppi - 16 bit - TIFF
Neat Image
Unsharp Mask at Amount = 100, Radius = 1.8, Threshold = 8
I only do one pass at USM but I have heard of some very exotic settings.
keoj
Pherdinand
the snow must go on
one trick is to zoom in to something that should be sharp-sharp, to say 500% so you can count pixels. Then count how many pixels does it take to pass the sharp edge. Half of that will be a good radius for the usm setting.
Then you can adjust the amount to a value that does not give you halo or destroy tonality but give back sharpness. Sometimes i need only 40-50, sometimes 100-120.
I usually have my threshold set to 3 or 4 not more.
When grains are mre visible, i sometimes do multi-pass usm with lower amounts per pass. Seems to help.
Then you can adjust the amount to a value that does not give you halo or destroy tonality but give back sharpness. Sometimes i need only 40-50, sometimes 100-120.
I usually have my threshold set to 3 or 4 not more.
When grains are mre visible, i sometimes do multi-pass usm with lower amounts per pass. Seems to help.
mfunnell
Shaken, so blurred
I don't often use "plain" unsharp mask as I use Focal Blade's after-market plug-in instead (about, say, 90% of the time). I guess I'm working backwards from digital, but my starting point for "plain" USM has always been Canon's recommended values for their dSLRs (to compensate for the AA filter) of 300%/0.3radius/0 threshold. For film scans I tend to increase the radius (depending on the resolution I've re-sized to) and the threshold value.
My work-flow usually goes - scan, Neat Image, resize (usually 3000 pixels in the longest dimension is good enough for me), make other corrections as required, save as unsharpened TIFF, re-size again if required then sharpen for final JPEG.
For a final print of A4 size (using that 3000 pixel longest dimension) and using USM I tend to sharpen at something like 250-300%, 0.4 radius and threshold of 4-10.
...Mike
My work-flow usually goes - scan, Neat Image, resize (usually 3000 pixels in the longest dimension is good enough for me), make other corrections as required, save as unsharpened TIFF, re-size again if required then sharpen for final JPEG.
For a final print of A4 size (using that 3000 pixel longest dimension) and using USM I tend to sharpen at something like 250-300%, 0.4 radius and threshold of 4-10.
...Mike
tetrisattack
Maximum Creativity!
The radius and amount for the unsharp mask depend on the output size and resolution.
I typically do a gentle USM before resizing for printing or the web and usually do a second one on the resized image.
Since the radius is different every time, I start by setting the amount to 500% and the threshold to 0 and then I plug numbers into the radius field until I find the happy medium between turning the image into total noise and having obvious halos around everything.
With the radius figured out, I then scale the amount down to between 80 and 200%.
I always leave the threshold at 0 because I don't like the artifacts it introduces.
I'll often do a second USM to enhance the general detail contrast of the image, and for the second pass I start by doubling the radius and halving the amount.
Avoid oversharpening. Too much and the image will really start to look "cooked" in photoshop.
I typically do a gentle USM before resizing for printing or the web and usually do a second one on the resized image.
Since the radius is different every time, I start by setting the amount to 500% and the threshold to 0 and then I plug numbers into the radius field until I find the happy medium between turning the image into total noise and having obvious halos around everything.
With the radius figured out, I then scale the amount down to between 80 and 200%.
I always leave the threshold at 0 because I don't like the artifacts it introduces.
I'll often do a second USM to enhance the general detail contrast of the image, and for the second pass I start by doubling the radius and halving the amount.
Avoid oversharpening. Too much and the image will really start to look "cooked" in photoshop.
keoj
Established
This is an excellent dialog and info.....it's amazing the range of settings and the flow that folks use. Thanks everyone.
keoj
keoj
MelanieC
Well-known
Out of curiosity, why start off with Neat Image? I am wondering what I could get out of trying that. I don't reduce noise very often and if I do it's usually the absolute last thing I do. Of course, I am pretty much winging it so the logic behind this is shaky to non-existent.
mfunnell
Shaken, so blurred
Starting with Neat Image is so that subsequent corrections (especially changes to contrast - which sharpening is part of - and dredging detail out of shadow areas) don't overly accentuate the noise or grain that's there in the original. That's my logic, anyway, and it usually works for me.
...Mike
...Mike
dmr
Registered Abuser
keoj said:
I almost always scan at 3200, highest mine will do.
If I use Neat Image, I do sharpening there, don't try to use USM in addition.
I'm also confused with the USM settings. I may try it more since reading this thread.
jlw
Rangefinder camera pedant
Quick theoretical explanation which might help some people in understanding what USM settings to try:
Sharpening was unnecessary in the days of analog output. A dot-based analog output device (such as a halftone screen) could make any shape of dot necessary to handle the detail structure of the image. If you had a hard edge going through a halftone dot, for example, the screening process would simply generate a pear-shaped or hourglass-shaped dot.
Digital output devices can't do that, because they're constrained to a fixed repertoire of output dot shapes -- whether they're the pixels of a monitor, the dither cells of an inkjet printer, or the predefined halftone dot shapes of a PostScript imagesetter. Sharpness inevitably would be lost when image edges passed through these dots, because the dot couldn't modify its shape. To compensate, digital imaging developers introduced various forms of sharpening, which simply exaggerates the edges of the image so they're bold and thick enough for a fixed dot pattern to reproduce them.
Unsharp masking exaggerates edges by heightening the contrast of the tones surrounding the edge; the closer to the edge they are, the more their contrast is increased. (This is why it's called "unsharp"; the selection mask that locates the edges is blurred so that the sharpening effect is applied more strongly closer to the edge. You actually can produce the effect yourself by using Photoshop's 'Find Edges' filter, saving the result as a selection channel, and then blurring it. You're doing exactly the same thing the Unsharp Mask filter does.)
Now that you know basically what's going on, you can understand what the three settings do.
-- Radius determines how far on either side of the edge the filter applies the sharpening; a low number focuses the effect tightly on the edge itself, while a high number adds contrast over a broader swath. Focusing the effect too tightly can prevent the sharpening effect from being visible; focusing it too broadly creates artificial-looking lines around the edge, like the heavy outlines around shapes in a comic-book illustration.
-- Amount simply controls how much the contrast is boosted near the edge. A higher amount creates a sharper-looking effect, but again, overdoing it will make the effect look artificial.
-- Threshold gives you some control over what the filter considers to be an edge that needs to be sharpened. Set it to 0 and the filter will think ANY difference in contrast is an edge that needs to be sharpened; the result is a drastic exaggeration of grain, noise, and other textures. Set it too high and the filter won't identify any edges that need to be sharpened at all.
Knowing this won't necessarily help you decide WHAT settings to use for a particular image being output on a particular device, but at least you'll understand what you're varying when you change the settings.
I think it's best to start by determining the radius -- it's the most important value, since it controls the width of the "track" along the edge (and remember from the start of this explanation, it's the thickness of this "track" that simulates sharpness by making the edge thick enough for the output device to render it.) How wide a track you need depends on the pixel resolution of your output device; if your printer resolves 240 pixels per inch, for example (good guess value for many inkjets) then the "track" won't be visible if it's much thinner than 1/240 of an inch at the final output size. If you want, you can figure out how many image pixels are represented by 1/200 of an inch or so of printer output, and use that as a starting point for your radius setting. Most of us, though, just use radius values that we've learned by experience give good results for various output devices and image sizes.
Once you've got a starting radius, you set the amount (remember, this controls how much the contrast is boosted along the edge) based on the structure of the image -- images with low "microcontrast" need higher amount settings. I always suspect that if I have to go over 150-160%, it's too much (although sometimes you need to do this to produce a specific effect.)
And finally you set the threshold so that you're applying sharpening to image details but not to artifacts such as noise and grain -- start with it at 0 and move it upward until these artifacts are excluded from the sharpening effect.
Addendum: I don't actually use USM much any more. I find that the "Smart Sharpen" filter in the newer versions of Photoshop is easier to use and gives more natural-looking results. If you've got it, try it!
Sharpening was unnecessary in the days of analog output. A dot-based analog output device (such as a halftone screen) could make any shape of dot necessary to handle the detail structure of the image. If you had a hard edge going through a halftone dot, for example, the screening process would simply generate a pear-shaped or hourglass-shaped dot.
Digital output devices can't do that, because they're constrained to a fixed repertoire of output dot shapes -- whether they're the pixels of a monitor, the dither cells of an inkjet printer, or the predefined halftone dot shapes of a PostScript imagesetter. Sharpness inevitably would be lost when image edges passed through these dots, because the dot couldn't modify its shape. To compensate, digital imaging developers introduced various forms of sharpening, which simply exaggerates the edges of the image so they're bold and thick enough for a fixed dot pattern to reproduce them.
Unsharp masking exaggerates edges by heightening the contrast of the tones surrounding the edge; the closer to the edge they are, the more their contrast is increased. (This is why it's called "unsharp"; the selection mask that locates the edges is blurred so that the sharpening effect is applied more strongly closer to the edge. You actually can produce the effect yourself by using Photoshop's 'Find Edges' filter, saving the result as a selection channel, and then blurring it. You're doing exactly the same thing the Unsharp Mask filter does.)
Now that you know basically what's going on, you can understand what the three settings do.
-- Radius determines how far on either side of the edge the filter applies the sharpening; a low number focuses the effect tightly on the edge itself, while a high number adds contrast over a broader swath. Focusing the effect too tightly can prevent the sharpening effect from being visible; focusing it too broadly creates artificial-looking lines around the edge, like the heavy outlines around shapes in a comic-book illustration.
-- Amount simply controls how much the contrast is boosted near the edge. A higher amount creates a sharper-looking effect, but again, overdoing it will make the effect look artificial.
-- Threshold gives you some control over what the filter considers to be an edge that needs to be sharpened. Set it to 0 and the filter will think ANY difference in contrast is an edge that needs to be sharpened; the result is a drastic exaggeration of grain, noise, and other textures. Set it too high and the filter won't identify any edges that need to be sharpened at all.
Knowing this won't necessarily help you decide WHAT settings to use for a particular image being output on a particular device, but at least you'll understand what you're varying when you change the settings.
I think it's best to start by determining the radius -- it's the most important value, since it controls the width of the "track" along the edge (and remember from the start of this explanation, it's the thickness of this "track" that simulates sharpness by making the edge thick enough for the output device to render it.) How wide a track you need depends on the pixel resolution of your output device; if your printer resolves 240 pixels per inch, for example (good guess value for many inkjets) then the "track" won't be visible if it's much thinner than 1/240 of an inch at the final output size. If you want, you can figure out how many image pixels are represented by 1/200 of an inch or so of printer output, and use that as a starting point for your radius setting. Most of us, though, just use radius values that we've learned by experience give good results for various output devices and image sizes.
Once you've got a starting radius, you set the amount (remember, this controls how much the contrast is boosted along the edge) based on the structure of the image -- images with low "microcontrast" need higher amount settings. I always suspect that if I have to go over 150-160%, it's too much (although sometimes you need to do this to produce a specific effect.)
And finally you set the threshold so that you're applying sharpening to image details but not to artifacts such as noise and grain -- start with it at 0 and move it upward until these artifacts are excluded from the sharpening effect.
Addendum: I don't actually use USM much any more. I find that the "Smart Sharpen" filter in the newer versions of Photoshop is easier to use and gives more natural-looking results. If you've got it, try it!
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I work with PS everyday ... not that it makes me any expert, but I do teach it in the photography program I teach at college.
There are two different approches that I use...... all of these are from digital files taken with a digi camera.... I don't tend to use many images that were scans.
If the image is going to be printed as a photograph I tend to use 120.... 2....2 on the unsharp mask. If the shot is a little soft (OK when it's my shot it's soft when it's your shot it's out of focus) I might go up to 200... 2.... 2 or use the lower 120 setting twice. The unsharp mask is the last thing I do to the photo... after sizing and colour correcting.
The other case is work that I do for the Hamilton Spectator daily newspaper. At the paper the photographers have "Unsharp" mask turned off on the camera so all images start off a little soft. As photo editors we apply unsharp mask to every photo as part of the production cycle. It's the last thing we do... the settings are crazy 380... 1.... 2.
It basicly ruins the photo to look at but it comes out sharp in the paper. I've tried lower settings but they don't look sharp in the final paper.
For what it's worth.
Rob Skeoch
www.bigcameraworkshops.com
There are two different approches that I use...... all of these are from digital files taken with a digi camera.... I don't tend to use many images that were scans.
If the image is going to be printed as a photograph I tend to use 120.... 2....2 on the unsharp mask. If the shot is a little soft (OK when it's my shot it's soft when it's your shot it's out of focus) I might go up to 200... 2.... 2 or use the lower 120 setting twice. The unsharp mask is the last thing I do to the photo... after sizing and colour correcting.
The other case is work that I do for the Hamilton Spectator daily newspaper. At the paper the photographers have "Unsharp" mask turned off on the camera so all images start off a little soft. As photo editors we apply unsharp mask to every photo as part of the production cycle. It's the last thing we do... the settings are crazy 380... 1.... 2.
It basicly ruins the photo to look at but it comes out sharp in the paper. I've tried lower settings but they don't look sharp in the final paper.
For what it's worth.
Rob Skeoch
www.bigcameraworkshops.com
BJ Bignell
Je n'aurai plus peur
I use GIMP, but have had considerably less success than I had in the past with Photoshop. To put it in plain words: I just don't use USM anymore, because I can't get the results I want.
Is there anyone with significant experience with USM in GIMP and Photoshop who could comment on the differences? Or, is it just me?
I'm also going to try the "zoom to 500%" trick for determining radius, and see if it helps me any.
Is there anyone with significant experience with USM in GIMP and Photoshop who could comment on the differences? Or, is it just me?
I'm also going to try the "zoom to 500%" trick for determining radius, and see if it helps me any.
FrankS
Registered User
I'm a digi-photo processor newbie, so please bear with me: is the order in which a series of manipulations is done important? I'm guessing resizing would be the last?
VinceC
Veteran
>>It basicly ruins the photo to look at but it comes out sharp in the paper.<<
When I printed b&w photos for my newspaper 15 and 20 years ago, I had to give them crazy contrast in order to print nicely. They were usually way too severe to look at, but the printing process added so much gray that they ended up looking fine.
When I printed b&w photos for my newspaper 15 and 20 years ago, I had to give them crazy contrast in order to print nicely. They were usually way too severe to look at, but the printing process added so much gray that they ended up looking fine.
I always do my crop first.... if I need the same picture in different sizes I crop to the largest size and do all my colour corrections, burning, etc. Then I save it as a large file. I keep an untouched version of the file, as well as this large file.
When it's time to make prints I just resize the image, apply the unsharp mask and resave it. I keep the largest size on file since it has the burning and dodging... I resize and apply unsharp mask each time I have to get prints made of different sizes.
Rob Skeoch
www.bigcameraworkshops.com
When it's time to make prints I just resize the image, apply the unsharp mask and resave it. I keep the largest size on file since it has the burning and dodging... I resize and apply unsharp mask each time I have to get prints made of different sizes.
Rob Skeoch
www.bigcameraworkshops.com
tkluck
Well-known
"Quick theoretical explanation which might help some people in understanding what USM settings to try:..."
Once in a while you read a thread and it's as if a cartoon light bulb pops on over your head! Thanks.
Once in a while you read a thread and it's as if a cartoon light bulb pops on over your head! Thanks.
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rollo
Newbie
FrankS said:
You should resize before you sharpen - this is essential because resizing will change the number of pixels across the edge you are working with.
Touching up is best done at the highest resolution you work with. That way, if you resize downwards, any touching up crudeness will be averaged over a smaller number of pixels and will look less harsh.
robertdfeinman
Robert Feinman
Why sharpen
Why sharpen
There are two reasons to sharpen. The first is to make up for deficiencies in either the scanner or digital camera. Depending upon the device this can be with a radius of under a pixel to 3-4. You do this as a first step after opening the file.
I use a mask when I do this so that I don't sharpen areas with no detail like the sky. This reduces grain effects.
The second sharpening is done at the end. This is to adjust for problems in the output media. The general rule for print files is that the radius should be about 1/100 inch. So a 300 dpi file for an inkjet printer would have a radius of about 3.
I also keep the level to around 7 to avoid increasing grain and the amount about 180.
For the web the dpi is 72-96 so sharpening should have a larger radius. I find the resize with sharpening option in PS has good settings for this.
I have a few discussions about this in the tips section of my web site if you are interested.
Why sharpen
There are two reasons to sharpen. The first is to make up for deficiencies in either the scanner or digital camera. Depending upon the device this can be with a radius of under a pixel to 3-4. You do this as a first step after opening the file.
I use a mask when I do this so that I don't sharpen areas with no detail like the sky. This reduces grain effects.
The second sharpening is done at the end. This is to adjust for problems in the output media. The general rule for print files is that the radius should be about 1/100 inch. So a 300 dpi file for an inkjet printer would have a radius of about 3.
I also keep the level to around 7 to avoid increasing grain and the amount about 180.
For the web the dpi is 72-96 so sharpening should have a larger radius. I find the resize with sharpening option in PS has good settings for this.
I have a few discussions about this in the tips section of my web site if you are interested.