Static Montage: Masks and Modes
    Isolating image elements and effects
    Arch 5710, Photography and Digital Media,, University of Virginia
     Copyright © 1999-2009 Kirk Martini.Last Modified Tue September 22, 2009 10:15    		 Table of
    Contents
    The photographer, like an artist, is at liberty to employ what means he thinks necessary to carry out his ideas. If a picture cannot be produced by one negative, let him have two or ten; but let it be clearly understood, that these are only means to an end, and that the picture when finished must stand or fall entirely by the effects produced, and not by the means employed.

    C. Jabez Hughes, 1861

    Layer Masks

    A layer mask makes it possible to set the transparency on a pixel-by-pixel basis.


    Original image
    Layer mask

    Masked image

     
    Setting a mask pixel to white makes the corresponding layer pixel completely opaque.

    Setting a mask pixel to black makes the corresponding layer pixel completely transparent (e.g. turns the pixel off, effectively erasing it).

    Setting the mask pixel to gray makes the layer pixel semi-transparent, with darker greys corresponding to higher transparency, and light greys corresponding to higher opacity.

    Masks may be created and modified with any tools (brushes, filters, etc.).

    A layer with a mask can be manipulated in either mask mode or paint mode.


    Mask mode.
    Paint mode.
    • Click on the mask icon.
    • The effects of tools are applied to the mask.
    • You can see the effects of the mask changing the opacity of layer pixels.
    • To see the mask itself, alt-click (Mac: option-click) the mask icon.
    • To see the mask overlaid on the image (like quick mask mode), alt-shift click (Mac option-shift-clidk) the mask icon.
    • To temporarily disable the mask, shift-click the mask icon.
    • Click on the layer icon.
    • The effects of tools are applied to the layer (as usual).

    Using masks to combine different versions of one image


    Original color image on lower layer


    Greyscale version (50R-30G-30B) on upper layer

    Layer mask for upper layer.
    Color version shows through according to the darkness of the layer mask.

    Cheating on contrast

    Using tonal range tools alone, a gain of detail in one tonal range means a loss in another, but by using the image to mask itself, it is possible to gain detail in both shadows and highlights.

    Original Image

    Contrast adjusted for detail in shadows
    Contrast adjusted for detail in highlights

    Blue channel from darkened version
    Darkened version for use as mask.

    Contrast adjusted for detail in shadows
    Highlight image with mask applied.

    Original image
    Merged image.

    Isolating image effects: Masks for adjustment layers.

       
    Add a Curves adjustment layer, set a mask over the sign with blurred and grey areas to blend in.

     

    Montage

    Arch 5710, Photography and Digital Media,, University of Virginia
     Copyright © 1999-2009 Kirk Martini.Last Modified Tue September 22, 2009 10:15     		Table of
    Contents