Levels and Colour - Midtone contrast preserving WP and BP

[tomczak]

This is just for the record: I've been introducing a friend with no experience in image processing to the wonders of PWP. She likes Levels and Colour a lot, because it can adjust all major aspects of the image with little fuss. The only thing that she lacks is the ability to easily change the midtones contrast, while preserving the white and black points - she doesn't like having to use curves.

As far as I know, there is no easier way of adjusting contrast in PWP. Would implementing such option in the 'Swiss Knife' transformation of PWP be a good idea?

[den]

...How about the Composite-SoftLight or HardLight transform where the Input and Overlay image are the same?...

Black, midtone-brightness [50% tone/colors], and White would be preserved from the Levels&Color adjusted image version, however there would be slight color changes as this is a RGB transformation rather than a HSV or HSL transformation... perhaps acceptable for low Amount settings of the Composite-SoftLight/HardLight transform.

For a 'luminance only' [HSV-V] transformation: 'lower-left' Apply Add a Mask Tool - Brightness Curve default diagonal curve=[0,0],[100,100] as an 'active mask' to the Levels&Color image version... then use Composite-SoftLight/HardLight where Input=the Levels&Color image version; Input Mask white and black = 100 or None; Overlay = the 'active mask'... adjust Overlay Amount to preferences.

[tomczak]

Another slider-friendly way of adjusting contrast could be using 3-Tone's midtone Contrast Change slider, but this is like killing a fly with a sledgehammer, plus the 3-Tone's plethora of options can be quite intimidating at first.

[Charles2]

Another method: Look at Special Effects | Equalize, examining both HSV and HSL and make a choice. Sometimes the amount slider will find a suitable result. When it does not, Composite | Soft Light the original as the base image and the equalized image as the overlay, adjusting the amount slider of the latter. When the equalized image is a harsh over-contrast, try using it as the overaly in Composite | Subtractive Filter.

[tomczak]

Just to report on an old thread: I was introducing another 'student' to PWP. After going over the basics, Levels and Colour seemed like logical choice to start. Everything went fine, until the contrast adjustments - it became complicated without having a dedicated slider(s) or another simplified transformation based on curves (akin to Brightness or Saturation) to adjust the midtones contrast.

Cheers!

[tonygamble]

If anyone around here uses Lightroom 4.1 they will know of a slider called Clarity.

I think this is a midtone contrast adjustment - though I can't be sure.

Whatever it is the results are, to me anyway, impressive. It would be great to have an emulation of that slider on PWP.

Tony

[tomczak]

Tony, I'm not sure, but I understand that the said 'clarity' slider applies something akin to a local contrast enhancement - i.e. USM with v. large radius, watered down by using small Amount. This sometimes work, but often produces halos that are disliked by many viewers in the end product, yet difficult to detect when you apply the transformation:

http://www.dl-c.com/discus/messages/2/3562.html

What I was suggesting is just having a slider (or it could be a more sophisticated dual Highlights/Shadows slider similar to the one that works so well in the RAW Gray control) that would facilitate using brightness curve to redistribute global contrast, but without actually having to learn how the curves work.

Cheers!

[tonygamble]

Maciej,

I looked at that rather old thread. Interesting.

Den does not mention threshold. Do I assume it was zero?

Tony