Photoshop Tricks page1

home page
.Photoshop Blending Modes
Unlike Photoshop's built-in filters, blending modes don't change the actual pixels that make up an image, so their effects are completely reversible.

STEP 1 - In the Layers palette, duplicate the original image layer by dragging the background layer onto the "Create a new" layer icon, or use Ctrl/Cmd-J.
STEP 2 - Using the pull-down blending mode menu in the Layers palette or the shortcut Alt/Opt-Shift-U, change the new layer's blending mode to Hue, and rename it "Hue."
STEP 3 - Invert the Hue layer using Ctrl/Cmd-I.
STEP 4 - Change the Hue layer's opacity to 50%. At this stage the image is almost grayscale.
STEP 5 - Duplicate the Hue layer and change the new layer's blending mode to Color Dodge using the shortcut Alt/Opt-Shift-D. Name the new layer "Color Dodge."
STEP 6 - Increase the Color Dodge layer's opacity to 100%.
STEP 7 - Apply a small amount of blur to the Color Dodge layer with Filter > Blur > Gaussian Blur. Use a small radius -- 5 should be enough to emphasize edges within the picture.
STEP 8 - Use Ctrl/Cmd-J to duplicate the Color Dodge layer and set the new layer's blending mode to Pin Light using the shortcut Alt/Opt-Shift-Z; name it "Pin Light."
STEP 9 - Invert the new Pin Light layer using Ctrl/Cmd-I.
STEP 10 - Go to Image > Adjustments > Desaturate or use Ctrl/Cmd-Shift-U to desaturate the Pin Light layer.

.Hand Tinting a Grayscale photograph
 
What we're looking for here is not truly lifelike color, but a decorative and subtle effect. Essentially, we can tint as little or as much of the image as we like, but the effect works best where areas of color are contrasted with the uncolored grayscale image.
Here's how...
* Open a suitable image.
* Go to Image > Mode.
If the original image is in color, first convert it to grayscale.
Then convert it back to RGB so we can add color back into it. If the original is grayscale, it'll need to be converted to RGB mode.
The color needs to be painted onto a separate layer, so create a new layer (Ctrl/Cmd+Shift+N). Set the blending mode for this layer to Color in the Layers palette. This mode will allow any added color to overlay the image.
Choose the Brush tool and select a soft-edged brush from the Brush Picker.
In the Options bar, set the brush opacity to 50% and activate the Airbrush icon.
Before the age of color film, when black-and-white photography was the only option, it was common practice for photographers to tint a black-and-white image with colored dyes to mimic real-life colors.

display the Colors palette.
This is where we will choose all of the painting colors.

To make accurate application of color easier, zoom into the image and adjust the size of the brush with the square bracket keys on the keyboard.
To choose a color, pass the mouse pointer over the spectrum bar and click to choose the approximate color. The colors can be fine-tuned with the RGB sliders above the bar, and the chosen color can be seen in the foreground swatch. Remember, because the brush is in Airbrush mode, if we leave the brush in one position for too long the color will build up on the image, so we need to keep it moving at all times.Vary the color slightly by occasionally dragging the RGB sliders. Remember, we only want to tint the image with color.
Basic terminology used for describing blending effects is:
Base color - this is the color that is already there. The one that you are going to paint over, onto, or add a layer on top of.
Blend color - the color you’re going to add with your paint tool, or which is already on the layer for which you are selecting a blend mode (the layer will be blending with the layers below it).
Result color - what you get after you do some “blending.”
Please note that the blend modes that are found on a tool’s options bar affect how the colors or actions caused by that tool blend with the colors that are already on the current layer that you have selected in the Layers palette. Those tool blend modes do not affect how those colors blend with the layers below that layer once the color or effect has been applied. This also applies to the blend mode chosen when using Edit > Fade; it affects how the colors are blended with the existing colors on the current layer. The blend mode setting in the Layers palette determines how each layer’s colors blend with the colors of all other layers below it in the Layers palette.
Normal - This is the default setting. The color applied is the color you get. In some of the color modes, this may be called Threshold.
Dissolve - If you read Adobe’s explanation of this one, I guarantee a headache. You’re better off looking at the picture in the manual. It looks like what you see when a movie does a dissolve into a new scene; there are little speckles of the scene you’re leaving mixed with the just emerging colors of the new scene. Dissolve only affects partially transparent pixels.
Behind - this allows painting, or color additions only to transparent parts of a layer. By definition, you must have Preserve Transparency turned off on the layer you are painting on. The existing image will mask whatever you add with this blend mode, and new color will only be added to empty areas.
Clear - only available for the line tool, the paint bucket, and the Fill, and Stroke commands. This blend mode makes every pixel transparent. Naturally, the layer it’s being applied to must not have Preserve Transparency checked.
Darken - looks at the two colors, the color already there, and the one you’re painting with, and chooses the darker one, whichever it is. No blending. Whichever is darker wins. Which of the two is used will vary across the image according to which is darker at each spot. This I can understand.
Multiply - multiplies the base color with the blend color. I can almost understand this one. Clearly the resulting color will be darker. I still have to try it to see what color I’ll end up with before I know if it’s right. Black times any color equals black. White times any color leaves that color unchanged. Light colors have less effect, dark colors have more effect. Repeated strokes with this blend mode produce darker and darker colors.
Color Burn - supposed to be the opposite of Color Dodge. What it looks like is, the color applied to light areas is unchanged by the underlying colors, while color applied to darker areas is dramatically darkened.
Linear Burn - Uses the color data from each channel,“darkens the base color to reflect the blend color by decreasing the brightness” (quoting from the User Guide).
Lighten - reverse of the above. As the new color is applied, if it’s lighter than the color already there, it replaces that color. If it’s darker than the color that’s already there, it is not added.
Screen - From the Adobe manual, “Looks at each channel’s color information and multiplies the inverse of the blend and base colors.” Gee, that’s really helpful. Just think of it as making the light parts a lot lighter, the dark parts a little bit lighter, leaves the black parts unchanged, and nothing gets any darker.
Color Dodge - the Adobe manual says it “… looks at the color information in each channel and brightens the base color to reflect the blend color.” I have no idea what that means, and the illustration doesn’t help. It looks like the color applied to light areas is bright, but pale, and the color applied to dark areas is barely visible.
Linear Dodge - The inverse of Linear Burn. Uses the color information from each channel to brighten the base color according to the blend color.
Overlay - multiplies (darkens), or screens (lightens) the colors depending on the base color. Totally unpredictable; try it and see if you like it.
 
Soft Light - if the color being applied is lighter than mid-gray, the image is lightened. If the color being applied is darker than middle gray, the image is darkened.
Hard Light - if the colors being applied are lighter than mid gray, screen mode (see above - lightens) is applied. If the colors being applied are darker than middle gray, multiply mode (see above - darkens) is applied.
Vivid Light - Dodges or burns the colors base colors depending on whether the blend colors are brighter or darker than middle gray. This mode works on contrast while Linear Light works on brightness.
Linear Light -Dodges or burns the colors base colors depending on whether the blend colors are brighter or darker than middle gray. This mode works on brightness while Vivid Light works on contrast.
Pin Light - Replaces the base colors depending on the brightness of the blend color. If the blend color is lighter than middle gray, base colors darker then the blend color are replaced. And the reverse; if the blend color is darker than middle gray, base colors lighter than the blend color are replaced.
Difference - another of these mathematical ones. I don’t need this … okay, it says it looks at the two colors, and, subtracts the less bright from the more bright one. Therefore, blending with white inverts the color values (you are subtracting color values of 100 % so you go all the way to the inverse), while blending with black makes no change (black has zero color values, so you subtract zero). Having figured all that out, you still have to do trial and error to see what the colors will look like. This one changes the colors, not the brightness.
Exclusion - says this is a lot like Difference (above) but with less contrast. It’s good to see that the Adobe people don’t know how to describe these things, either. Try it and see what it’s like.
Hue - uses the hue (color) that you’re adding (the blend color), but the luminance (brightness) and saturation (richness) of the base color (the color already there). Not as hard as some of the previous ones, but I’d still have to try to see if I liked it.
Saturation - just like hue, but this time the saturation (richness, depth) of the new color is used, while the luminance (brightness or darkness) and hue (color) of the original image are used.
Color - the result of this blend has the luminance (brightness or darkness) of the base or original color, but the hue (color), and saturation (richness) of the new, or blend color. This blend mode is commonly used for colorizing black and white images.
Luminosity - uses only the luminance (brightness or darkness) values of the new or blend color. All hue, and saturation values of the blend color are ignored. This is a useful mode to choose when using the Sharpen tool.
This book is superb the above method is based on it.