USING PHOTOSHOP V8 or V9
Written by Tad Boniecki on 12 March 2006, last modified 14 January 2017
These notes incorporate material from Scott Kelby's "The Photoshop Book for Digital Photographers"
Photoshop is widely regarded as the state of the art image editing program. So whatever you want to do to an image you should be able to do it using this program. The downside is that Photoshop can do much more than any one individual is ever going to use. Hence the key to gaining a working knowledge of the program is to identify the sort of things you want to do and how to do them.
Preliminary settings to facilitate colour corrections
These settings are helpful for auto color and a few other things, but are not mandatory.
1) Click on the eye-dropper tool and select 3 x 3 average for the options.
2) Open an image. Cntl-m then double-click on the left eye-dropper. Enter 20 for R, G, B and hit OK. Double-click on the right eye-dropper. Enter 240 for R, G, B and hit OK. Double-click on the centre eye-dropper. Enter 128 for R, G, B and hit OK. Click OK and save as defaults.
3) Hit cntl-l and then Options. Set "Find light and dark colors" and "Snap neutral midtones". Single click on each of the 3 rectangles and check that the same RGB values are present for highlights, shadows and midtones as in 3) above. Click "Save as defaults" and OK.
4) View -> Snap off so that you can adjust the cropping window precisely.
1) To undo an action (very useful)
Alt-cntl-z to undo the last change - can hit this repeatedly.
Hit cntl-z to flip between undo and redo. Never worry about mucking up the image. Undo will save the day.
2) To create a macro
Window->Actions->New Action (2nd last button at bottom right) then name it, select a key (eg F11) and hit Record. Do the keystrokes you want to put into the macro. Then hit the stop button at extreme left.
If you spend many hours on photo corrections then it is almost mandatory to set up some actions to do routine things, like resizing, sharpening and colour-cast correction.
3) To decrease the effect of the last change (extremely useful)
Edit -> Fade. I think this is the best feature of PhotoShop. Use it!
4) To repeat the last filter
Cntl-f but only if you used the filter during this session.
5) To save a file as
Cntl-shift-s, modify the name and hit CR twice. Sadly, the "save as" dialog is unable to accept a default setting for jpg quality. Or hit alt-i twice. To get around this annoyance simply hit CR twice when saving to a new file name. Just make sure it really is a new name, else you will lose the old one. In this case the jpg quality question will appear after the second hit of CR. You should never save your corrected version over the top of your original ie change the file name instead.
I used to be quite happy with the quality setting for jpg of 8, but in some cases this introduces quite a lot of noise, eg in clouds and sky. I have now standardised on quality = 10. My hard drive will just have to take it on the chin.
Hit 'c' and draw the crop area. Move the mouse outside the cropped area to rotate the image. Hit CR.
To resize for screen display
Image-> Image size and specify pixels to be your screen resolution and choose resample Bicubic sharper.
To enlarge a photo using a macro
Window->Actions->New Action (2nd last button at bottom right) then name it, select a key (F11) and hit Record. Hit control-alt-i. Resample must be on. Select percent and 110. OK. Then hit the stop button at extreme left. Hit F11 15 times to get about 4 times linear enlargement ie 64 mpixels from 4! The F11 key increases size by 10%. This works amazingly well. I made a 70 by 50 cm poster print from a 4 mpixel snap that does not look over-enlarged. To get an idea of how a large print will look view it at 25% magnification.
To lighten a photo (or darken it)
1) Hit Cntl-j then Layer-> Layer Style-> Blending Options then select "Screen" for Blend Mode. Hit OK then punch Cntl-j as many times as required. If it is over-done then use 50% (say) for the last hit. Cntl-z to undo. Use 'multiply' instead of 'screen' to darken. Finally, do Layers->Flatten image.
2) Use Image -> Adjustments -> Brightness/Contrast. Generally, if you increase the brightness then you should also increase contrast to avoid a washed-out look.
3) Image -> Adjustments -> Levels and then move the 3 pointers below the graph to set the black, mid-grey and white points.
4) Try Image -> Adjustments -> Exposure to darken the shadows by decreasing the offset value.
To lighten shadows or darken highlights ie to make the image more evenly lit (extremely useful)
1) Image -> Adjustments -> Shadow/Highlight and adjust as needed. Works very well for shadows but not so well for highlights - can re-apply if need be. Make sure you set "color correction" to not get a red cast - slide it left if need be. Try darkening the highlights if the photo is washed out or foliage is yellow instead of green. For some reason, when you move the shadows slider to the right it initially does the opposite, just persevere.
If you want to lighten or darken just one part of an image, eg to leave the highlights in the water undimmed but to darken a bright rock, then use lasso to make a rough selection around the over-bright rock and dim it. If darkening the highlights also darkens the midtones then decrease the "Tonal width" for the highlights and try again.
Dimming the highlights is very useful for brightening up a dull-looking image because it adds contrast in a non-destructive way.
2) Image -> Adjustments -> Levels and then move the 3 pointers below the graph to set the black, mid-grey and white points.
It is also worth giving auto levels and auto contrast a hit to see whether it makes the photo better.
To increase (or decrease) contrast
1) A very quick and easy way to improve most photos is Image -> Auto Contrast. Perhaps not so good for people shots but ideal for murky photos with very little contrast.
2) It is better to increase local contrast rather than the global setting. To do so apply the Unsharp Mask with values (20, 50, 0). Use Fade if the effect is too strong. Use this sparingly.
3) Image -> Adjustments -> Shadow/Highlight. Decrease the Shadows amount to 0 and then slide midtone contrast to the right. This can give a lot of oomph without the tone drop-out effect you get with strong use of method 3).
4) Use Image -> Adjustments -> Brightness/Contrast. This method is rarely the best one to use.
5) In many cases, especially hazy or washed-out photos, the best control to use to put some zip into the photo is
Image -> Adjustments -> Shadow/Highlight. Try darkening the highlights. You may be surprised how this improves the photo.
Note that increasing the contrast will cause colours to become more intense and tends to increase any colour cast that is already present. Likewise, decreasing the brightness will have a similar effect. Conversely, increasing brightness or decreasing contrast makes colours less intense. Be warned: increasing the contrast can erase nuances in the highlights. As a general rule, if you increase contrast you should increase brightness in the same measure. As a rule of thumb, do not increase contrast by more than about 10.
To correct colours
1) Image-> Adjustments-> Curves-> Auto. This usually works well but always check and undo or fade it if not. Immediately after applying auto color you can diminish its effect by Edit->Fade curves and moving the slider. Auto color may do a good job but require a touch-up eg more contrast. It tends to make the photos washed out and too cold (usually blue) in colour, so fading the effect helps.
2) Cntl-m (or Image-> Adjustments-> Curves) then click the three droppers on the black, white and midtone grey parts of the image. Failing that you may get away with using the lightest, darkest and mid-tone areas, but don't count on it. To find the mid-tone (ie the mid grey value) use Window->Info then click on "Total ink" and look for 128% value. Also: lift the curve upwards in the middle a bit to lighten the mid-tones. If a grey mid-tone cannot be found (as is often the case) then use the color adjustment to remove red or whatever from mid-tones. Even adjusting just one of the settings (eg highlight) can be very worthwhile.
It is a good idea to click the middle dropper in an area where there is a pronounced colour cast. Then Edit -> Fade to decrease the correction. Even if the correction was much too extreme before the Fade, this can work well.
3) Image -> Adjustments -> Color balance and try your luck. Use Image -> Adjustments -> Variations to get an idea of what cast you have. If in doubt experiment with the six changes. You can combine this method with 1) and 2) above. Use the eyedropper tool in RGB mode to test for a colour cast eg in a shadow area of a white object.
4) Image -> Adjustments -> Levels then select the colour of the cast and decrease it by pushing the left slider to the right to remove the colour of which there is too much. This works better than 3) above. It's best to slide the slider only as far as the black graph. You might be able to use the middle dropper to select a mid-tone grey to remove the cast.
5) Image -> Adjustments -> Match Color and tick Neutralize to remove the colour cast. Optionally adjust Luminance, Intensity and especially Fade, then OK. Try this if the other methods fail, but you may need to fade it, often to 50%. It tends to give a blue cast.
6) If a colour cast is hard to get rid of (ie any change seems to introduce yet another colour cast) then simply decrease the saturation of the offending colour (cf correcting flesh tones below). This is useful if tungsten lighting has given an overall yellow cast. This method will remove the most stubborn stains!
7) If everything else fails then turn it into a greyscale image.
8) To repeat the last colour correction you did using Curves, hit alt-cntl-m on the next image.
9) If still stuck, try using Image -> Adjustments -> Hue/Saturation and then move the hue slider slowly.
To match the colours of another image
Open both images in PS then Image -> Adjustments -> Match color and select the source image and hit OK. Use Fade if the effect is too strong. This is useful if there is a photo of a similar scene with correct colours, which you want to copy. It works quite well but always check the results carefully.
To correct for colour cast due to PhotoShop operations
Sometimes radical sharpening, highlight/shadow or removal of noise cause the colours to change. If so, save the original image and then match its colours after the cast-inducing operation. Or redo the colour correction, or colour correct as the last operation.
To correct flesh tones
Image -> Adjustments -> Hue then click on Edit and select Reds. Then decrease the saturation till the flesh tones look OK. Don't overdo it, as you get a bloodless effect. Of course you should do it for yellow instead if the person looks jaundiced, but red is the usual culprit.
To change viewing size
Use alt-ctrl-zero or view->actual pixels to see it full size. Use cntl + or - to zoom in or out.
To rotate a photo that is a bit askew
Select the measure tool (right click just above the magnifying glass) and draw a line that should be horizontal or vertical. Then Image->Rotate->Arbitrary and then crop it.
1) The best tool in Photoshop 9 is probably Smart Sharpen ie Filter -> Sharpen -> Smart Sharpen. I use the options Basic, Amount 39, Radius 1.1, "Remove Lens Blur" and "More Accurate". This seems to work better than Unsharp Mask but it is difficult to compare directly. If it causes too much speckling then fade it. If you want more sharpening then hit control-f.
2) Filter->Sharpen->Unsharp Mask
for people & other soft targets 150, 1, 10
for maximum or if many hard edges 65, 4, 3
for general purpose 85, 1, 4 Can apply this twice sometimes
for blurred photos 400, 0.3, 0
Custom: try amount 50 to 150, radius 1 to 2, threshold 3 to 20.
3) Set Image -> Mode -> Lab then Window -> Channels and click on lightness. Now apply the Unsharp Mask as above but with higher values eg 100, 4, 3. Then reset Image -> Mode -> RGB. Make this into an action. Warning: this may alter colours.
4) Filter->Sharpen->Unsharp Mask and select radical sharpening eg 150, 4, 3. Then Edit -> Fade unsharp mask and choose mode = luminosity. Hit OK. Warning: this may alter colours.
Try applying half the sharpness you expect to give in two hits to see how much it can take. Two small hits of unsharp mask seem to work better than one big hit.
Cntl-F to repeat last unsharp mask. This only works if you sharpened using Unsharp Mask as the last filter action during this run of the program. Currently I use unsharp (40, 1, 4) and do this two or three times. Don't forget you can fade sharpness if it is too strong.
Since over-sharpening is most easily seen on the horizon, one trick is to sharpen the entire image except for the horizon. It might be worth doing radical sharpening before, rather than after downsizing an image. Note also that the effect of any given unsharp mask setting will depend on the image size. The larger the image the smaller the effect.
The three filters below are good for removing digital noise. Noise is essentially small-scale distortion of the colour of the image, giving a mottled effect, where a uniform area of shadow has tiny red and green blotches. Noise becomes particularly acute if you lighten an area that is badly under-exposed. It is severely ugly in an under-exposed face. To remove noise it is probably best to apply a filter - Gaussian blur is best - before downsizing the image. All corrections come at a cost in image quality, so it is a matter of trading off gains against losses. Use fade to select the best balance of noise versus clarity.
In PS9 try using Filters -> Noise -> Reduce Noise, which works rather well for both fringe noise and speckled noise. However, be aware that this often bleeds colour out of the image. If so, you can either increase the saturation after reducing the noise, or you can make sure that the noise reduction is not applied to colourful parts of the image.
To remove mottled effect
Select the part of the image that has noise. Use Filter->Blur->Smart Blur. It will soften the image (though it respects contours) but those green and purple dots can be pretty offensive. It is better to do this before down-sizing the image. This is good for removing digital blotches on people's faces caused by underexposure. Fade it if the effect is too strong. It does not remove coloured fringes.
To remove digital noise (coloured fringes or mottled effect in areas that should have uniform colour)
Filters->Blur->Gaussian blur and move the slider till noise disappears and hit OK. Then Edit-> Fade Gaussian blur and select Colour and hit OK. Warning: watch for colour drain. You may need to colour correct afterwards. A much better method is to lasso the noise in a few rough selections and then to apply the blur only to those selections. This avoids altering the colours in other parts of the image. Essentially, this method replaces a coloured fringe by a grey one. Try using Hue or Saturation instead of Colour.
To remove little coloured dots 1
These may appear due to dust, over-sharpening or adverse conditions. Filter -> Noise-> Dust and scratches. A value of 1 should be sufficient. This will soften the focus as well. Try using fade if it goes too soft. Also try Filter-> Noise-> Despeckle. This works well but softens the focus. If you want to see what is really happening in this and other subtle operations then increase the zoom factor till the nature of the changes becomes obvious.
To remove little coloured dots 2
Select the part of the image that has noise. Set Image -> Mode to Lab Color. Windows -> Channels and click on the 'a' channel. Then Filter -> Blur -> Gaussian Blur and set the radius so that the dots pretty much disappear. Then click on the b channel and hit cntl-f to apply the same blur. Set the mode back to RGB. The effect is to reduce the colour of the noise dots, so that noise is less visible. Watch out for colour drain.
To remove heavy noise
Use level 6 of RP DNR Action. You must first download the Photoshop actions from Noise removal actions.
To make greyscale images
1) Image -> Mode -> Lab color. Window -> Channels and click on Lightness then Image -> Mode -> Greyscale. Window -> Layers and click on Background and hit cntl-j. Switch the mode from Normal to Multiply. Finally, lower the opacity from 100% to the value that looks best.
2) Image -> Adjustments -> Channel mixer and click on Monochrome. Select different percentages for R, G and B, but make sure they add up to 100%. Adjust the overall brightness using the Constant slider. For an "Ansel Adams" effect try R = 160%, G = 140% and B = -200%. Try the same using mode CMYK instead of RGB.
3) Image -> Calculations then choose two channels such as R and G. Experiment with combinations of R, G, B and Grey channels. Change the blend mode and lower the opacity till you get what you want. Then under Result choose "New document" and OK. Finally, Image -> Mode -> Greyscale.
4) Image -> Adjustments -> Desaturate.
5) Image -> Mode -> Greyscale.
To batch rename files
Look up the help for "batch rename files". Go into the file browser and select Automate -> Batch rename. You can add text to the existing file names or replace them entirely with a new text prefix plus serial number and date (optional). The catch is that PhotoShop will not let you type letters into its input boxes. To get around this bug, type the text you want into another program and pick it up and put it down into the input box. Then it works beautifully.
Example: to rename all the files in a directory to have the names P1160301 through P1160646 type in "P1160" into the first box, choose "3 digit serial number" for the second and "extension" for the third (to keep the jpg extension). Start the serial number at 301.
To select part of an image
1) Filter->Extract and click on the tool at top left of the dialog box. Paint the outline at the border of the object you want to select, ie half inside and half outside it. Then click the 2nd tool from the top and click inside the object you want to select. Click the Preview button. If it looks more or less OK then hit the OK button - you will clean up in a minute. Hit cntl-j and cntl-e. Enlarge the image using cntl-+ then select the history brush (5th one down in the tools menu). Use this to paint back in the bits missing from the subject selected. Then remove unwanted bits using the eraser. If you make a mistake hit cntl-z. It is advisable to do the paint-back and erasure in small sections so the undo will only undo a small bit each time you make a mistake. Adjust the size of the brush and eraser to make life easier. If your hand is not steady on the mouse increase the zoom factor and decrease the size of the tools. If you want perfect results then go down to the pixel level, though this is not recommended unless you want to spend a lot of time. If you cannot use the history brush because the canvas size has changed then start with the same canvas size.
2) Select the Magic wand and click on the background of the subject. Select -> Inverse to swap the selection to be the subject. This works well with homogenous backgrounds. Use the shift key to add to a selection.
3) Select the Magnetic lasso (it is with the standard lasso) and draw short line segments around the object you want to select, clicking each time you want to change direction. This works well on clearly defined edges. Double click to finish.
To put down one image into another image
Select the image element you want to add to the target image as above. Use the magic wand or magnetic lasso to pick it up from its white background canvas. Keep using shift and click until all of the image you want is selected. Go to the target image and put it down. Use the move tool (top right in the tools) to place it where you want it. Flatten the layers using control-e.
To merge two images using layers
Open each image then hit shift-cntl-n and OK to create a new layer in one of the images. Windows->Layers will take you into the blank layer. Pick up the second image and put it down into the layer using cntl-a and cntl-insert then shift-insert. Then Layer -> Layer Style -> Blending Options and move the slider to the desired position. Flatten the image and save it.
To remove red-eye
1) Zoom into a red eye. Select the eye-dropper tool and click it on the colour you want to replace the red with eg a healthy part of the eye. Select the Color Replacement tool, which is 4th from the top on the left in tools (you may need to right click). Choose a brush about half the size of the red-eye. Make sure that Mode is Color. For the Sampling option, choose Once to erase only areas containing the colour that you target. For the Limits option, select Discontiguous to replace the sampled colour wherever it occurs under the brush. Drag the Tolerance slider to 30 to replace only the few colours very similar to the pixels you click. Click on the colour you want to replace and then drag over the red areas. (This method used to work for me but now it replaces the colour with grey instead of my selection.)
2) Quick method to replace a red-eye with a grey eye. Zoom in to the eye. Select the brush tool and select a soft-edged brush that's nearly as big as the area of red you want to remove. Press 'd' to select black as the foreground colour. In the brush options select mode of 'color'. Paint directly over the eye with the brush. Do all the other red-eyes.
3) This is a more involved but better method to replace red-eye with natural colour. Zoom in really closely on one eye. Press 'w' to select the Magic Wand tool. Click inside the red area. Hold shift down and click on any red area not yet selected. If it selects too much then decrease the tolerance parameter. When all the red in one eye has been selected do the same to the other eye (use shift). Hit shift-cntl-u to desaturate. Press 'd', get the brush tool and select a small soft-edged brush. Lower its opacity setting to 20%. Paint over both eyes till they are dark gray, but not black. Don't worry about spilling over outside the iris because of the selection made. Deselect using cntl-d. Press 'l' to choose the lasso tool and draw a rough selection around each iris. Hit cntl-j to create an eye layer. Choose Hue/Saturation and check the colorize box. Using the hue slider pick a colour to use for the iris - ideally the real colour of the eye. Click OK. Press 'e' for the eraser and set the mode to brush. Choose a hard-edged brush. Erase the extra areas around the iris from the selection. Adjust the opacity slider till the eyes look natural. Hit cntl-e to merge the layers.
1) If nothing seems to work, eg you cannot select parts of the image, then check whether the image needs to be flattened. If so, use Layer-> Flatten image.
2) If you get an error message saying that the file you are trying to save is "already open" then find the file with a name such as ~xx in your working directory and rename it to have the file name that you wanted. Or else save it as another name.
What I typically do these days is:
a) Look at the photo at
100% magnification and decide whether to use the whole image or a crop.
Sometimes I do both, especially for wildlife and macro.
b) Downsize to 1280 x 1024 for screen display and email..
c) Adjust shadows and highlights for the entire image. I do this about 90% of the time.
d) Remove the blue cast that my expensive Canon 30D should not produce. Gripe, gripe, gripe!
e) Sharpen using Smart Sharpen. I do this 99% of the time. I like my photos to be as sharp as possible, provided there is no visible degradation.
f) Save it as a new name and flash between the original and the retouched image to convince myself I have improved it without over-doing it. This step is essential.
Here are two examples of what a difference the above steps can make:
How to correct a photo? Firstly, ask yourself what matters in the photo and what doesn't. What sort of effect do you want? Then see what could be improved and go through the sequence:
1) Improve the composition eg cut out the distracting bits.
2) Resize for screen display and email (but not if you want to print it).
3) Correct any colour cast (if present).
4) Adjust brightness. This is usually best done by lightening the shadows and darkening the highlights separately (unless the subject is evenly lit).
5) Adjust contrast (but be very careful with this).
6) Sharpen (this is almost always worth doing).
7) Diminish noise, if needed.
8) Save it as a new file name.
9) Compare with the original by flicking between them in full screen mode. This step is very important. If you are not entirely happy with the results then undo some of the changes or start again.
Note that all of these steps are optional. If the photo looks just right as it comes from the camera then no changes may be needed. Be aware that every modification you make to the original photo degrades it in an objective sense, ie removes some information. So it is best to err on the side of caution. Initially, you may find you are adding a lot of contrast or sharpness to make your photos look dramatic, but after some hours of looking carefully at your photos you will probably notice the loss of dynamic range and the sharpening artefacts these actions entail.
How much sharpening? There is no set answer. Perhaps the best idea is to sharpen until it is overdone ie you see halos, too much speckling, too hard-edged, or a rough texture (grainy). Pay particular attention to diagonal lines, outlines and horizons to check whether they are jagged or over-emphasized. Look closely at the finest details - is there too much contrast here? Does the flower look like it has been cut out with scissors? If so, use Fade or Undo. Also, it depends on the subject. Flowers seem to come out well with fairly strong sharpening, people do not. Lawns and stone buildings do not look right if sharpened very much. Blurry shots require radical measures, though of course, sharpening can never restore missing detail. All it does is increase the contrast at colour boundaries.
When are the colour balance and lightness correct? When the image looks OK to your eyes as you view the screen (assuming your monitor is set to appropriate contrast and brightness for the lighting conditions). As with sharpening, the rule I use is to correct the visible colour cast (eg too much red) in steps until it is over-corrected then undo or fade the last correction.
How to avoid the “boiling frog” effect? If you gradually slide a Photoshop control you may, by degrees, habituate yourself to an effect that is too strong. There are two ways around this problem. Firstly, apply the effect then toggle cntl-z to see whether the overall effect is too weak or too strong. In a similar vein, you can apply a “binary chop” as follows. Say you want to increase the contrast. Try adding a heap of it eg 40, which will be far too extreme. Undo that and then try 20. If that is still too strong then try 10, and so on. Fade and Undo are the two best bits of Photoshop and I use them constantly. Another solution is to save your two different versions and come back to see which is better tomorrow.
Be careful with increasing contrast, as this tends to wash out subtle gradations of tones, especially in flower petals.
How do I tell what colour cast is present? Go to Image-> Adjustments -> Variations. This will show you the effect of making six colour changes to your image. If you look at the image that looks the worst of the six variations that should tell you which colour is too strong, so add the opposite colour. Or try all 6 versions to get some practice. It's easiest to notice the colour cast in the part of a white object that is in shadow - it should be neutral grey, ie the RGB values should be equal. Another way to notice what colour cast is present is to flip between the colour and greyscale versions of the image, or to invert the colours. If the greyscale version looks like it has a colour cast then you have been staring at the screen too long! Think of it as re-calibration.
Be aware that a photo may have multiple colour casts, eg fixing a blue shadow may make something else look too red. Thus a correction may improve parts of the image but degrade other parts. This happens often. The solution is to select the part of the image that the correction will benefit and apply it only to that. Often the selection does not have to be exact. For example, the horizon or some other contour may acquire a white border after sharpening. To avoid this select the contour, invert the selection and then sharpen. Remember that what matters most is to make the main subject look good - don't worry about a bit of a colour cast in an unimportant area. Another good option is to compromise by doing half the correction, so that no part of the image looks obviously wrong.
Final checks? Always compare the final corrected version with the original by flicking between them in full screen mode - it may well be worse! You may find you have lost the profile of a mountain peak or the clouds due to too much brightness, or that you have step-wise gone too far in enhancing the original. Check the entire image for colour fringes, unnatural sky, green spots, blue shadows, white speckles, jagged diagonal lines or whatever. Also, the charm of the original image may rely on under-exposure (say), and correcting this may make the photo bland. Some photos should have soft focus whereas in others you may just want a silhouette. Sometimes you have to compromise eg make the subject look good at the expense of the background.
Basically you can have one of two goals: esthetics or authenticity, ie to make the photo look good or to make it as accurate as possible to the original scene. These two goals are not usually in conflict but occasionally they will be, in which case you need to make an executive decision. Correcting a photo involves being sensitive to its nature, eg does the image call for strong or weak contrast, should it be hard-edged or soft-focused, evenly lit or not. Another problem is that it is hard to know what to do with photos taken under unusual lighting conditions (eg at sunset or indoors) - is it better to make them look 'normal' or to allow the colour cast that the unusual lighting imposes?
Ideally, every photo should be treated afresh ie one should not just apply a standard routine of steps. There is as much room for creativity in the postprocessing as in the picture taking. Occasionally, the whole charm of an image may be due to an accidental technical flaw. On the other hand, quite often a really bad photograph can be transformed into something rather good, or at least acceptable. However, if the original is good it may need no correction or just a touch of sharpening.
Foreground & background colours - "Photoshop uses the foreground colour to paint, fill, and stroke selections and the background colour to make gradient fills and fill in the erased areas of an image. The foreground and background colours are also used by some special effects filters."
"A slice is a rectangular area of an image that you can use to create links, rollovers, and animations in the resulting Web page."
A stroke is a coloured border.
Swatch = square window showing colour etc
PS for fun (warning: this can eat up your spare time)
1) Try the filters. I recommend Sketch -> Chrome. Then fade it to about 80% and increase saturation to say 70% to get the colours back and then increase contrast. Optionally, try overlaying the original image by putting it down over the chromed version and adjusting the Layers -> Style -> Blending options to say 50%. Then flatten the image.
1a) Even better, try Sketch -> Chrome. Then fade and select some of the modes other than Normal. I recommend Color Burn, Overlay, Difference and Subtract. This retains colour without actually fading.
2) Stylize -> Find Edges, which you may want to apply once or twice or fade. Good for a blast, especially on city-scapes and people, is Stylize -> Glowing edges.
3) Filter -> Liquify is good fun to play with, especially contrasty shots and night scenes.
4) Filter -> Artistic -> Water Colour will give an oil-paint sort of effect. Try fading it.
5) If you like colour, lots of it, try Adjustments -> Hue/Saturation and slide the saturation to the right. Fasten your seatbelt.
6) To radically alter colours use Adjustments -> Hue/Saturation and slide the hue pointer.
7) To radically alter colours use cntl-m, click on the middle eye dropper and then click at various points of the image. The colours will shift to the opposite of the colour where you click.
8) Another way to get novel colours is to use match colour (see instructions above) to get colours from one image into another. Some surprising results.
9) Fun distortions are Filters -> Distort then Glass, Ocean Ripple or Spherize.
10) Use Adjustments -> Invert to get a negative image. If you just want colours reversed then use Adjustments -> Hue/Saturation and slide the hue pointer to extreme right. If you want to reverse dark/light but with colours unchanged then Invert and use the hue slider. Of course you can do any intermediate setting as well.
11) Use layers to mix different versions of the same image to achieve the blend that you want.
12) Use Stylize -> Find Edges, raise contrast and desaturate, then copy the original and merge at about 65% of the original predominating and finally raise the contrast and saturation of the merged image. This results in a painterly image.
13) Hit control-M to get Curves then raise the curve at the 1/4 point and lower it at the 3/4 point, or vice versa. This causes some surprisingly colourful effects.
14) Try Image->Adjustments->Posterize, setting number of levels to a small value.
15) To remove all greys from a BW image, do cntrl-m and click on the left dropper. Then click on a light grey in the image.
16) Try Image->Adjustments->HDR Toning and experiment with the various settings.
NB It is wise to save your shortcuts in case of a re-install. To do so, click on the name of the actions to save in the Actions window, click on the right arrow symbol and choose Save.
F2 to resize a horizontal photo
Shift-F2 to darken blown-out highlights (Adjustments -> Replace Color, click on result square and set colour # (below 'B') to ffffff, set fuzziness to 200, lightness to -10.)
Control-F2 reverse colours
F3 to increase contrast using Kelby's 3-point method Curves
Shift-F3 to remove blue cast
F4 to sharpen strongly - check for colour changes. This is sharpen method 3 shown above. Can fade this one.
F5 to reduce horizontal size to 240
F6 to do standard sharpen ie unsharp mask (45, 1, 4)
Shift-F6 to do smart sharpen (see under sharpening)
F7 to rotate a vertical shot, scale it down
F8 to sharpen people (150, 1, 10)
F9 to sharpen (130, 0.3, 0)
F10 to increase local contrast ie unsharp mask (20, 50, 0)
F11 to enlarge by 10%.
F12 to enlarge to 70 x 52 cm, ie 2 hits of sharpen (45, 1, 4), 300 dpi no resample, 4% larger resample, 13 hits of F11 (then save it as a tif file)