Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: Jeremy Roussak on July 10, 2009, 03:57:49 am

Title: Clarity and LCE: help, please
Post by: Jeremy Roussak on July 10, 2009, 03:57:49 am
I posted a plea for Jeff's help in a thread on the User Critiques forum ("Mountain scene"), but he didn't bite, so here goes again.

Schewe, could you explain, if possible in words of one syllable, what the difference is between LR's clarity slider and local contrast enhancement using an unsharp mask with a large radius in PS? Please?

Jeremy

(or anyone else who knows, of course!)
Title: Clarity and LCE: help, please
Post by: francois on July 10, 2009, 10:46:06 am
Jeremy,
Read  this article (http://photoshopnews.com/2007/05/31/about-camera-raw-41/) . This should give you an idea about the differences between Lightroom's clarity and USM (scroll down to about 3/4 of the article).

HTH
Title: Clarity and LCE: help, please
Post by: Schewe on July 10, 2009, 12:55:39 pm
Quote from: kikashi
...what the difference is between LR's clarity slider and local contrast enhancement using an unsharp mask with a large radius in PS?

Clarity is a one setting preset for a radius 100 midtone or local area contrast adjustment. Clarity also rolls off the highlights and shadows so to duplicate it in Photoshop would require using the Blend If sliders of the Layer Style menu. So, the big difference is that with a single slider you control midtone contrast in ACR/LR while in Photoshop you have to manually do about 1/2 dozen steps.
Title: Clarity and LCE: help, please
Post by: JeffKohn on July 10, 2009, 02:15:30 pm
Quote from: Schewe
Clarity is a one setting preset for a radius 100 midtone or local area contrast adjustment.
Good to know what the radius setting is.

Quote
Clarity also rolls off the highlights and shadows so to duplicate it in Photoshop would require using the Blend If sliders of the Layer Style menu. So, the big difference is that with a single slider you control midtone contrast in ACR/LR while in Photoshop you have to manually do about 1/2 dozen steps.
Well, you only have to record the action once.   My action does a 'merge visible', sets blend mode to Luminosity, adjusts the blend-if sliders, and then pops up the USM dialog so that I can play with both the amount and radius settings. And since it's a new layer I have the option to mask if necessary.

The only reason I ever use clarity is for images that aren't making the trip to Photoshop at all (unfinished proofs, snapshots, etc).

Title: Clarity and LCE: help, please
Post by: Schewe on July 10, 2009, 04:27:00 pm
Quote from: JeffKohn
The only reason I ever use clarity is for images that aren't making the trip to Photoshop at all (unfinished proofs, snapshots, etc).

Never used negative Clarity in the Adjustment Brush? Kinda hard to duplicate that in Photoshop...
Title: Clarity and LCE: help, please
Post by: Jeremy Roussak on July 11, 2009, 05:52:32 am
Quote from: Schewe
Clarity is a one setting preset for a radius 100 midtone or local area contrast adjustment. Clarity also rolls off the highlights and shadows so to duplicate it in Photoshop would require using the Blend If sliders of the Layer Style menu. So, the big difference is that with a single slider you control midtone contrast in ACR/LR while in Photoshop you have to manually do about 1/2 dozen steps.
Thanks, Jeff. That explains a number of things that were puzzling me.

Jeremy
Title: Clarity and LCE: help, please
Post by: Chris_T on July 11, 2009, 07:20:44 am
Quote from: JeffKohn
Well, you only have to record the action once.   My action does a 'merge visible', sets blend mode to Luminosity, adjusts the blend-if sliders, and then pops up the USM dialog so that I can play with both the amount and radius settings. And since it's a new layer I have the option to mask if necessary.

I have a similar action for LCE. But I USM first, and only adjust the blend-if sliders to recover clipped highlight/shadow if any should result from the action. The adjustment amount depends on how much clipping there is. With your action, do you adjust the blend-if sliders before USM? If so, are the slider adjustments pre-set to certain values for all situations?

Some would apply Gaussion blur after LCE, but I can't see any differnces and skip that.
Title: Clarity and LCE: help, please
Post by: JeffKohn on July 20, 2009, 06:10:13 pm
Quote from: Chris_T
I have a similar action for LCE. But I USM first, and only adjust the blend-if sliders to recover clipped highlight/shadow if any should result from the action. The adjustment amount depends on how much clipping there is. With your action, do you adjust the blend-if sliders before USM? If so, are the slider adjustments pre-set to certain values for all situations?
Sorry, should have been more precise. My action does USM first and then changes the blend-if sliders. I've never tested to see if the ordering of those two operations would be significant. The action always uses the same blend-if settings, but of course with layers I can always go back and change them if needed (which is rare). I'm mostly just using the blend-if to prevent highlights/shadows getting pushed too close to clipping, not so much to limit the overall affect to just midtones.
Title: Clarity and LCE: help, please
Post by: JeffKohn on July 20, 2009, 06:12:07 pm
Quote from: Schewe
Never used negative Clarity in the Adjustment Brush? Kinda hard to duplicate that in Photoshop...
Nope, I don't care for the effect negative clarity produces, but I would agree if you want that ACR is a good place to do it. Doesn't really change the point I was making though - when increasing local contrast you've got quite a bit more control doing it in Photoshop than you do with the Clarity slider.
Title: Clarity and LCE: help, please
Post by: Brian Gilkes on July 20, 2009, 07:22:47 pm
Clarity is useful when processing bunches of commercial images in Lightroom or out of RAW in PS. I wouldn't touch it for art prints. There is not enough control. LCE is a perceptual edit. It's use is creative and depends on what you want a specific image to look like. There is a lot of difference between ,say, USM at 40/40/00 and 20/60/00. Some images benefit from smart sharpen or hi pass rather than USM. Blending in Layer Styles is not only to prevent clipping but controls the range of tones to be affected. In Hi Pass  you can blend on Soft light or Overlay, or both on duplicate layers. It is almost always necessary to mask some areas. LCE is often best used with other perceptual edits, eg blended L channels. I also find these edits  need to vary with print size. It's like cooking really. There are heaps of recipes and heaps of ways of doing it. Depends a bit on who is coming to dinner. I think you just need to develop your own style and that is part of your signature in the image. Some stuff needs a supermarket style and some needs something more.
Have fun
Brian
www.pharoseditions.com.au