image self-multiplication

[pbandurian]

In the June 2009 issue of "Outdoor Photographer" is an article titled "Photoshop Tips from the Pros". In it Marc Muench says that to maximize image detail he exposes bright. To get detail back into the brighter parts of the image, such as in clouds, he suggests multiplying the image by itself, which darkens the entire image. There is more there which I won't repeat. This is of course for PS. I can't figure out how to do that in PW. The composite transformation enables adding an image to itself which is equivalent to multiplying by two. With the amount slider, I suppose ,you can effectively multiply by anything from one to two.

Any suggestions?

Thanks, Peter

[den]

The Composite transform in Filter Operation and the Filter transform in Additive method will multiple an image with itself if the image is used as the Overlay in the Composite transform or the Filter in the Filter transform.... then too, there is nothing that says you can't transform more than once.... but then the image tends to get way too dark...

This process tends to strongly darken midtones/shadows, with increases in contrast and saturation... utilizing RGB color space model characteristics.

A favored technique...
(1) open or click on a 'starting image';
(2) open the Mask Tool - Brightness Curve and 'lower-left' Apply-Add the default [0,0], [100,100] diagonal curve. Leave the Mask Tool 'active' on the 'starting image'; and
(3) click on the 'starting image' and open the Filter transform using the Additive method with the 'starting image' as the Input and Filter, the 'active' mask appears as a default with mask white=100 and mask black=0... adjust mask white, mask black, and ExposureCompensation to preference while monitoring Preview... Click OK or Apply.

I find that most images seem to respond well if mask black =5 to 10, mask white =100 or less, and ExposureCompensation = 1.05... by using the mask, you can limit how dark/saturated the image's shadows and lower-midtones get... use the Readout Tool to check for clipped Highlights...

[den]

Another possibility....

As an alternate to the Composite-Filter and Filter transforms, a RGB BrightnessCurve darkening, contrast 's-curve' could be used with the HSV-V channel 'active mask' (2):
Alt(3) click on the 'starting image' and open the BrightnessCurve transform, selecting the RGB color space, form and Apply a Smooth curve = [0,0], [40,20], [80,80], [100,100]. Adjust mask white and mask black Amounts to preferences while monitoring Preview...

If the resulting image version of (3) or Alt(3) is too saturated but the tonality is to preference, one could:
(4) click on the resulting (3) or Alt(3) image and open the Saturation transform, selecting the HSV color space and Preserve Low and High, and then decrease mid-saturations to a preference [perhaps -10 to -20%]

[den]

Yet.. more possibilities for increasing sky/cloud detail...

Create an asymmetrical Highlight tone range mask and form/apply a darkening, contrast curve in the HSL color space with the BrightnessCurve or ColorCurves transform. See 'Creating Beautiful Skies': http://www.dl-c.com/cgi-bin/discus/show ... 1#POST9161 and the Highlight Tone Range section of: http://www.ncplus.net/~birchbay/3tone/3tone.htm.

Also for changing Highlight tone range image content, consider using PWP5's 2-Zone or 3-Zone Adjustment transforms which will make changes in the HSV color space model...

As not all images are the same... some will respond better to the suggested techniques than others.