Frequency Separation - settings for 16-bit images?

[RobertAsh]

Hi,

Am really liking this technique, learned about it here on RetouchPro and found this very useful video on YouTube describing it.

Here are the steps described. The settings in Apply Image are for 8-bit images and the video author says she'd use different settings for 16-bit images.

1. Select Background Layer
2. Make 2 copies of it
   • Bottom is Low Freq (Color)
   • Top is High Freq (Texture)
3. Select Low layer
4. Gaussian Blur
5. Select High Layer
6. Image > Apply Image
   • Go to Layer, select Low Freq layer
     • Blending Mode = Subtract
     • (settings suggested for 8-bit images)
       • Scale = 2
       • Offset = 128
     • Invert box is unchecked
7. Go back to High Freq layer
8. Set blending mode to Linear Light

Which settings would be best for 16-bit images?

[mistermonday]

For 16 bit images change the blend mode to add and the offset to 0.
If you would like slot more info on this topic go to modelmayhem.com and search for the thread titled High Pass Sucks.
Regards, Murray

[creativeretouch]

Hi Robert, you can find a lot of informations regarding this technique here:

http://www.modelmayhem.com/po.php?thread_id=439098

[RobertAsh]

MisterMonday, CreativeRetouch,

Thanks a lot, this is really great stuff

Quick question - in that Model Mayhem article, its author posted this line as a reply to someone who responded that he'd never seen sharpness like that even after 20 years of doing it.

What does this comment mean (I bolded the part I'd like to learn more about)?

• "Just wait till you apply a clipping-masked curves layer to that high-frequency layer."

Thanks again,
Robert

[mistermonday]

Originally Posted by RobertAsh

MisterMonday, CreativeRetouch,

Thanks a lot, this is really great stuff

Quick question - in that Model Mayhem article, its author posted this line as a reply to someone who responded that he'd never seen sharpness like that even after 20 years of doing it.

What does this comment mean (I bolded the part I'd like to learn more about)?

• "Just wait till you apply a clipping-masked curves layer to that high-frequency layer."

Thanks again,
Robert

Robert, The High Frequency layer is equivalent to a layer to which you have applied a Filter>other>High Pass which is sometimes used to apply sharpening instead of the traditional Filter>Sharpen>USM or Smart Sharpen. Adding an Adj Curve layer on top of the high frequency layer (and clipping that curve to it) allows you to increase or decrease the contrast of the HF layer by making the curve an S Curve or inverted S Curve. Some people think this is a great way to sharpen. But I think it is way over-hyped. Most people don't realize that a High Pass layer on its own for sharpening is the equivalent to using the Unsharp Mask Filter at the same radius, with amount = 100 and threshold = 0. USM and Smart Sharpen have much more fine control and accuracy than using a HF layer or HF layer + a clipped curve. The advantage of using the HF layer and curve is that you do not need to create a merged layer on you stack to which you apply sharpening and for some people this makes their workflow more "non destructive / editable".
Regards, Murray

[RobertAsh]

Murray,

Thanks. This is starting to help me see how all of these techniques relate to one another. You also provide a sanity check to the over-excitement that invariably accompanies any good technique and creates competing camps.

For me, Frequency Separation is sort of a deja vu. I figured out my own method of increasing sharpness in very saturated images, one that's pretty close in concept - I use a good pre-sharpened layer on top of the saturated, less sharp layer and change the sharpened layer's blending mode until I get the right balance. Then I Stamp Visible and sharpen the resulting image.

Freq Sep is more organized and structured, and I don't use blur at all (I use the less sharp image at the bottom which has sort of a similar effect).

I'll work with Freq Sep and some of the other sharpening techniques more and compare them now that I've gotten a better handle on them over the past couple of years. Thanks again.

[ME_wwwing]

she forgot 2 things in the video. 1. change Smart Sharpening to Lens Blur. she has it set to Gaussian Blur. 2. make sure you check the box that says More Accurate.

i've been play with Smart Sharpening here
http://www.retouchpro.com/forums/pho...harpening.html

if you want more control over the Smart Blur - use 2 layers. change one Mode to Lighten and the other to Darken adjust the opacity of each layer.
using these two Modes gives you more control over Blurring.

[RobertAsh]

ME,

Thanks, will try these different approaches and refinements. Much appreciated.

[ME_wwwing]

your welcome.
i hope another video comes out by her correcting her settings