Favourite Sharpening Techniques

[ballroom_boy]

Hi there,

I find the topic of sharpening photos very useful. Just applying the USM in PS aggressively leads to that "pasted in digital look", and photos look fake. Not to forget, it will create some ugly artifacts.

I wanted to start a thread we could share what we've learned about sharpening.

My favourite is sharpening technique uses LAB colour mode. It helps to avoid colour halos that appear when you add a lot of sharpening. I use it all the time for print and web images.

1) open the image

2) go the "Channels" palette - you will see "RGB", "Red", "Green", and "Blue" channels.

3) Goto Image--> Mode --> Lab Color. You will be converting the image to LAB colour.

4) In the "Channels" palette, click on the "lightness" channel.

5) Increase your image size to 100%

6) Goto Filter-->Sharpen-->Unsharp Mask. I use the USM values of a=49%, r=0.7, t=0, and apply it. If more sharpening is required, repeat as necessary (I may apply this up to 4-5 times depending how aggressive I want my sharpening to be). Some of you may want to be more aggressive with your initial values, so experiment with this.

7) Click on "Lab" in the "Channels" palette to see your final result.

8) Goto Image-->Mode-->RGB Color -- this converts your image back to RGB.

Voila, there you have it!

I find when you sharpen in RGB mode, not only do you sharpen the image, but you also increase the chroma noise (and halos), which I find unacceptable. By converting to LAB mode, selecting the lightness channel, and applying USM to it, I avoid sharpening the chroma noise and create a cleaner looking image (Chroma channels are A & B channels in LAB mode).

Any other techniques you would like to share? :rofl:

[Swampy]

Let's not forget a slightly deeper way that I've seen and heard of, but have never done yet. Take all of your technique and while in lightness channel in Lab mode, select only the hard edges throughout the frame and sharpen.

For quick web publishing, I just sharpen the whole thing in RGB mode with 49%, .7, 0 settings once or twice as needed. For that serious print, I'll go into the lightness channel though.

[Bill C]

Roel: Yes, the method you outlined is a very good one - especially if the original has a lot of noise as most techniques done in RGB tend to make things worse in this situation. I have an action for download, if anyone wants it .... the USM values I use aren't probably optimal, but they seem to work for me. The action:

Goes thru the steps you detailed....and does the following:

Creates Two Snapshots in the History palette:
Before Sharpen
After Sharpen

Creates Two Layers - bottom layer is called Before Sharpen, and the Top Layer is called After Sharpen (clever, huh!)

An advantage of having both layers is that you can then change the opacity to 'fine tune' the sharpening

USM values I use 200%, 1.0, 0

I associate F12 with the action so It is a real quick process for me ... hit the F12 key to run the action ... go to 100% and either click on/off the top layer for comparison ...I can then adjust opacity to taste.

If interested, here's the action.. (don't bother looking at the main site, I haven't updated it for.....I can't remember!)

http://www.twinoakphoto.com/download/SharpenLABMethod.atn
(I've also run USM against the S2 pics in RGB mode with excellent results ... I also have NIK Sharpener Pro, but don't use it a lot)
Regards,
Bill

[GaryB]

Here is what I do. I take no credit for this - I think I originally found the technique on this forum.

Duplicate the layer

Deselect the original layer

Select overlay from the layers dropdown

Use filter -> other -> high pass and adjust do just the edges appear (normally about 0.3 - 0.4)

Select all layers and adjust the opacity to taste!

Hope you can understand this.....

Gary

[ewaldm]

I use this procedure:

http://www.microsoft.com/windowsxp/digitalphotography/learnmore/fixit/sharpening.asp

It works superb, I do mostly printouts in A3+

[HulaMike]

For the most part, I have stopped sharpening any image globally. No matter how careful you are, you're sharpening background elements which should remain soft(er) and noise as well as your main subject matter to the same degree. Many times this makes a digital image look, well, digital.

There are a number of selective sharpening actions and plugins available for Photoshop that analyze your image separating areas that should be sharpened more aggressively than others. I find the use of these to produce a more natural looking photograph with much grerater depth and less of a "digital" look.

I currently use Fred Miranda's Intellisharp with modification. The trick with this plugin is to use a low level of adjustment just to get the image areas separated and lightly processed. After that I use normal PS USM to taste followed by this step: Select Edit > Fade Sharpening > Luminosity > 100%. This step takes the "edge" off sharpened pixels while allowing the overall degree of image sharpening to remain.

[Wilm]

When I am postprocessing my pictures, I don´t like a global USM.

What I do is the following :

1st: Extract major elementes from the picture
2nd: Sharpen major elements using slight USM
3rd: put everything together again.

A real tutorial of USM x% y-diameter yadda yadda yadda ....

I don´t care. The result is for me more important, than to figure out a helpfull standart-workabout.#

From my personal point of view a standard-procedure won´t work because every picture is different.

Happy Holidays from Wilm ..... just playing with PS CS the complete evening.

[scottjua]

Originally posted by GaryB
Here is what I do. I take no credit for this - I think I originally found the technique on this forum.

Duplicate the layer

Deselect the original layer

Select overlay from the layers dropdown

Use filter -> other -> high pass and adjust do just the edges appear (normally about 0.3 - 0.4)

Select all layers and adjust the opacity to taste!

Hope you can understand this.....

Gary

same here... ALMOST. I use Hardlight as a blending mode instead, and I usually try two or three duplicate layers with different levels of the high pass filter and opacity before I settle on one. :D That way I can just turn on or off in the layers pallette instead of going back and forth in the history to see what changes have taken place.

[Claude Ollieuz]

I found an interesting discussion of sharpening "philosophy" at http://www.pixelgenius.com/sharpener/why.html