Post process sharpening question

[syuan]

What is the best way to sharpens images that will not introduce too much noise and still retain the bulk of image information? I'm kinda new at photoshop. Any advise appreciated.

[Concisus Cognatus]

A book turned out to be the most useful tool in my Photoshop learning experience. Scott Kelby's books are usually pretty good for beginners.

[Peruna]

There are many ways to sharpen. Here's how I was taught for CS3.

1. Set view to 100% if image is < 8x10, 50% if image is > 8x10
2. Filter - Unsharp Mask
3. Set Amount Slider to 500
4. Set Radius Slider to .01
5. Set Threshold Slider to 4
6. Slowly raise radius until sharpening begins looking fake (overly sharpened which is usually around .5 but the lower the better)
7. Lower Amount slider to less than 100 and look away from the image for 15-30 seconds.
8. Raise the Amount slider until just before the sharpening makes the image look fake.
9. Edit - Fade Unsharp Mask

[adirty1]

I like to sharpen on luminosity.
make a copy of your image
go to the red channel
turn all channels but red off
use unsharp mask
amount slider to 500
move the radius around till you get what you want sharpened
move amount slider back down till things look right.

normally it's about 28 percent amount slider and 3-5 on radius slider.
turn all your channels on
set blending mode to luminosity

then sharpen on normal mode with unsharp filter pretty much like Peruna explained.

you can get an image really sharp and create eyes that jump off the print. sometimes i just use the luminosity sharpening. just really depends on the image.

[krodgers]

i have come to the conclusion that there are so many ways to sharpen, it must be in the eye of the beholder.

[jayson]

I use the High Pass method of sharpening. duplicate your layer and change the blending mode to "overlay". Then go to the filters and select the high pass filter. Use the radius slider(the only slider) to adjust the amount of sharpening you want.

Jayson

[Duffy Pratt]

The easiest way might be to invest in Photokit Sharpener, which was developed by Bruce Fraser, who also wrote a very good book on sharpening (Real World Sharpening, I think).

In RGB, here's what I do. Make a duplicate layer. Set layer to luminosity. Then either Filter - Unsharp Mask, or Filter - Smart Sharpen.

If Unsharp Mask, I set the amount to 500, and the radius to 5. This will make stuff really ugly. I lower the radius until the halo's look like they are not swallowing up wanted detail. I raise the threshold until I'm not sharpening noise. Then I dial back the amount until it looks reasonable. (For portraits, I would do this on the Red channel only).

In Smart Sharpen, I would do it similarly, but you only have radius and amount to work with. I don't have a hard and fast rule for when I use one or the other.

For certain types of shots, I will do the sharpening on two separate layers. Sharpening creates white halos around dark areas, and black halos around white areas. Sometimes you want to emphasize one and not the other. The two layer approach would be similar to the above. One layer would be set to Lighten, and the other to Darken. Then I would apply the sharpening as I did above, to each layer, and then do a Fade - Luminosity immediately after each sharpen. Then I would adjust the opacity of each of the lighten and darken layers to taste.

Hope this helps,

Duffy

[syuan]

Thanks, y'all for the tips. They work great! Now I have natural looking, and sharp images for enlargement prints. Appreciate all of your expertise advise!