| Digital Image Photography Editing |
Digital Image Editing 101
Text and photos by Charlotte K. Lowrie
Taking the picture is half of the fun of photography. The other half of the fun is in the digital darkroom—getting that great
finished image that you can't wait to show off to everyone who's willing to look at it. "Yeah, right," you say, "but I'm not a
professional, and I know nothing about editing pictures."
While digital image editing often mirrors traditional "wet" darkroom picture processing, you don't have to have traditional
darkroom experience to perform everything from minor fixes to minor miracles with digital images. And in many cases,
you can save pictures you would have otherwise thrown away.
Notice that I said "many," not "all" cases. Regardless of the small miracles you can perform, there will be some images
that no amount of computer editing will fix. Image-editing software is good, but, alas, far from perfect. For example, if the
detail is blown out of highlight areas, no amount of editing will put detail into the area. You can use a cloning tool to
paint in detail from a similar area, but the process is tricky, tedious, and the results often look artificial.
But, if you follow good darkroom process and practices, my bet is that you'll get more keepers than you thought
possible. And, what's more, you can polish those exceptional images into a portfolio of "personal best" pictures that
you'll be proud to share and print.
Following are tips and a suggested process for correcting digital images.
Before you start editing pictures
Regardless of how much fun image editing is, you don't want to spend time on the computer correcting something that
could have been corrected during shooting. Rather, ensure that you use your image-editing time to perfect and polish
good pictures instead of salvaging images that have problems because the white balance, ISO, or mode was
incorrectly set.
So the first two best steps in image editing begin before you sit down at the computer:
Learn your camera gear inside and out.
Use your camera correctly when you take pictures.
An important starting point when you begin editing on the computer is to know what you are correcting "to" or "for." In
other words, what does a well-corrected picture look like? The following list provides some of the basics for correcting
photos. Not every item in the list will apply to every picture, and, of course, there will be exceptions such as high visual
impact pictures in which many of the guidelines should be ignored, but you can use this list as a starting place for
image editing.
Good contrast. In general, contrast is the difference between light and dark areas in a photo. A low-contrast image
will seem flat and dull with little difference between light and dark areas. A high-contrast image will seem harsh and
may have little detail in the highlight and shadow areas.
Realistic colours. Image-editing may be necessary for images with excessive colour casts caused by inaccurate
white-balance settings on a digital camera or not using a colour correction filter on film pictures for different types of
lighting.
Natural skin tones. If people are in the image, images should accurately reflect natural skin tones.
Good saturation. Look for colour that is strong and accurate. Images with unnaturally vivid colours may be over
saturated. Likewise, images with washed out colour are under saturated and can often be corrected in an image-
editing program.
An appropriate level of image sharpness. Depending on the digital camera or scanning settings, images may or
may not be sharp. Some people set digital cameras and scanners to no or low sharpening, and do all the sharpening
in an image-editing program. In any case, correctly sharpened images display good detail in all areas of the image.
Over sharpened images appear to have too much contrast and may show digital noise as well. Soft images lack detail
in all areas of the image. Soft images typically result from setting the image quality level too low on the camera.
The image-correction process
For those new to image editing, the process of image correction generally follows a sequence of adjustments that build
upon each other. A simple example is sharpening. Sharpening sounds like a good starting point for image editing,
right? Not so. In an image-editing program, sharpening makes the image look sharper by increasing the contrast
where there are significant colour changes, such as the edges. If you sharpen an image first, and then make other
adjustments, such as burning (darkening an area) or dodging (lightening an area), the subsequent editing can create
unnatural-looking edges and pronounced halo effects around objects in the picture.
Following a sequence, or "workflow," in the digital darkroom not only helps you get the best results, but also ensures
that you work with a high-resolution copy of the image for as long as you can before making final edits such as
cropping or resizing for printing.
Image correction process
If you are shooting RAW images, some of the following steps may be done in the image-editing program that converts
the RAW images to TIF or JPEG format.
1. Rotate, save, and correct a copy of the original.
2. Adjust the tonal range (brightness and contrast).
3. Adjust the colour balance.
4. Dodge and burn.
5. Correct flaws such as dust, scratches, and red eyes.
6. Crop the image.
7. Save a copy and size the copy for printing, sending in e-mail, or posting on the Web.
8. Sharpen the image.
1. Rotate, save, and correct a copy of the original. Before editing an image, rotate it to the correct orientation if
necessary, and always save a copy of the original file in a "lossless" file format such as Tagged Image File Format
(TIFF or .tif) and work on the copy. Although you may have taken the image in JPEG format, do not edit and continue to
save the image in JPEG format. JPEG files are small because they are compressed to save space on the memory card
and on your computer's hard drive. However, during compression, some of the image data is discarded.
If you're working on a JPEG image and you periodically save it as a JPEG as you work, the image will be
recompressed, and bits of the image will be discarded each time you save the file. While you may not notice a
degradation in the image on the screen, the more you save a JPEG, the more its resolution will decline.
Instead, start by making a copy of the original image in a format such as TIFF. TIFF files are significantly larger than
JPEG because TIFF does not compress files, and it does not discard bits of the picture. For this reason, TIFF is
referred to as a "lossless" format.
Also, keep your untouched original images, in whatever format you took or scanned them, in a separate folder. That way
you can always go back to the original if image correction doesn't go the way you want.
Note: If you use layers to make adjustments on your picture, such as adding text, borders, and so on, you'll want to save
the image in the image-editing program's native file format. That way you can go back later and change individual layers
in the image if you want to.
2. Adjust the tonal range (contrast and brightness).
The tonal range of an image is the distribution from light to dark pixels within the image. In an average exposure the
tonal distribution will have a fairly even distribution of dark, midtone, and light pixels.
Most image-editing programs offer automatic and/or manual tonal-level adjustment tools. Using the automatic option,
the program typically chooses the lightest and darkest pixels and distributes the midtone pixels proportionally. This is a
generalized approach to tonal adjustment, and it usually works best on images that have average tonal ranges.
However, on overexposed or underexposed images, automatic tonal correction may not only over darken or over lighten
pictures, but it may also introduce unwanted colour shifts or tints.
First try the automatic tonal adjustment. If the adjustment isn't what you want, then adjust the tonal levels manually.
Tip: Try the automatic tone and colour adjustments first, because if the results are good, they can save time in
processing images. If you don't like the results, you can undo the changes and make the adjustments manually.
Another good starting point for tonal adjustment is to set the white point. Setting the white point maps the lightest pixels
in the image to white. Some image-editing programs allow you to set both white and black points. Setting the black
point maps the darkest pixels to black. When you set a white and/or black point, the program adjusts the intermediate
levels proportionally.
3. Adjust colour.
Before you adjust colour balance, evaluate the picture. If you are working on a sunset picture, adjusting the colour,
especially using an automatic colour-correction option, may remove the warm sunset colours—something you don't
want to do. If you determine that colour correction will improve the image, first try the automatic colour adjustment
options. If they don't produce the results you want, then undo the change.
If you make manual colour adjustments, you should know that in most image-editing programs, making a single
adjustment to a colour in the image will affect all of the colours in the image. And it's good to know that you can correct
colours using opposite colours. For example, you can increase the amount of a colour by decreasing the amount of the
opposite colour on the colour wheel, and vice versa. So to decrease a reddish cast in a picture, you can increase the
amount of green, its opposite colour. To make the sky more blue, decrease yellow, its opposite colour.
For general purposes, remember that the opposite of red is cyan (green/blue), the opposite of green is magenta (bright
pink), and the opposite of blue is yellow. Typically, very small adjustments can make a big difference. Watch the picture
to see how the adjustment is affecting the entire image as you work.
Depending on the image-editing program that you use, there can be one or many ways to adjust colour balance.
Tip
The hue, saturation, and brightness options are especially useful in restoring faded colours in old family photographs
you've scanned.
If your image-editing program allows you to make colour adjustments by individual channel, you can fine-tune colour
corrections by channel, a method many professionals swear by. Or, if your program offers an automatic colour-balance
option, you can try that. Keep in mind, though, that the automatic adjustment changes all colours in the image, not just
the ones you want to change. In other words, you may get more change than you wanted if you use the automatic option.
4. Dodge and burn.
In traditional, or "wet," darkrooms, standard image finishing includes darkening specific areas of the image by
increasing exposure (burning in) or lightening other areas by reducing exposure (dodging). Burning in areas often
reveals more detail or de-emphasizes less important or distracting areas. Conversely, dodging can reveal details in
overly dark areas.
Most image-editing programs have tools that give the same type of results on the computer that you get in a traditional
darkroom.
Regardless of which tools you use, it's a good idea to start with a low-intensity setting and to choose a brush size that
is smaller than the object you're working on. Also, always know the command or key combination to immediately undo
any changes you make.
5. Correct flaws.
Scratches, dust, and lens flare are only a few of the many flaws you can fix in an electronic darkroom. Some of the most
affordable image-editing programs automatically correct many of these errors. However, if you're willing to take the
time, many such errors are better corrected by hand.
The cluttered background is distracting. It draws the viewer's attention away from the subject.
One of the best tools for fixing flaws by hand is the cloning tool. It allows you to paint one part of the picture into another
part of the picture, or paint from one picture to another. For example, you can paint over unwanted elements such as
light poles, or add elements such as trees or people.
Tip
When you use a cloning tool, take care to produce natural-looking results. Use short strokes and click a new starting
position often. When you repeat the same starting point multiple times within an image, you are likely to create an
artificial-looking pattern.
Other guidelines include matching the angle of light and the proportions for cloned and original objects. In other words,
don't paint a shrub from a shadowed area into a bright area of the image, and don't clone a foreground area into
smaller background shrubbery.
Crop and size the image
6. Crop the image. Although some recommend cropping as one of the first steps in the image-editing process, I prefer
to crop later in the cycle. Very often I do not see the "best" crop until I've worked on the image for a while. Of course, you
can crop as one of the first steps, but always crop with care. The advantage of cropping is that you can discard portions
of the image that you don't want or that do not contribute to the composition. You can also focus attention on the subject.
The downside of cropping is that it reduces the overall size (and, therefore, the resolution) of the image, thus limiting
how much you can enlarge the image for printing. For this reason, it is always best to do as much cropping as possible
in the camera as you take the picture.
For example, if you crop out a third of an overall image, the resulting image may not have a high enough resolution to
print larger than 5" × 7". To do an 8" × 10" enlargement, the image must be at least 1536 × 1024 pixels. And it follows
that to get a poster-size enlargement, it's a good idea to avoid cropping the original image at all.
7. Print, e-mail, or create a copy to post on the Web.
Assuming that by now you have a flawless version of a picture, you can make copies of the final image and size each
copy for the medium in which you want to print or display it.
If you choose to have the image printed professionally, the following table provides the minimum image dimensions
needed for each print size.
Print size (inches) Min. width (pixels) Min. height (pixels)
4 × 6 800 600
5 × 7 1050 750
8 × 10 1536 1024
11 × 14 1750 1375
16 × 20 (poster) 2500 2000
18 × 24 (poster) 2500 2000
24 × 36 (poster) 2500 2000
30 × 40 (poster) 2500 2000
36 × 48 (poster) 2500 2000
For use in e-mail or on the Web
The size you choose for images displayed on a computer screen is determined by the size, settings, and resolution of
the monitors on which the image will be viewed (unlike for images you are printing). It is important to make sure that the
pixel dimensions of your image are no larger than absolutely necessary for comfortable viewing. The only result of
making a file any larger than necessary is slow download times or rejection by the receiving e-mail server.
People can change the resolution of their monitors to just about any of the following resolutions, regardless of the size
of their monitors. However, for best readability of text, monitors most likely are set at a given resolution based on the
size of the monitor. For example, monitors in the 12-inch to 14-inch range generally display 640 pixels horizontally and
480 vertically (640 × 480). Fifteen-inch to 17-inch monitors are generally set to 800 × 600 pixels. Nineteen-inch
monitors generally display 1024 × 768 pixels. Larger monitors can display different numbers of pixels, such as 1280 ×
1024 pixels.
If you have a Web site, and you size an image as 640 × 480 pixels, the image will fill the screen of a 13-inch monitor.
Likewise, it will fill the screen of a 15-inch monitor that is set at 640 × 480; however, the pixels—and therefore the
image—will appear to be larger on the 15-inch monitor than on the 13-inch monitor. But if the 15-inch monitor is set at
1024 × 768 pixels, the pixels that make up the image—and therefore the image itself—will appear smaller.
Today, Web designers generally plan for a screen size of 800 × 600 pixels as the most common denominator, which
works for most monitors.
To size an image for online display, make a copy of the finished image, and then change the size of the copied image
to fit the screen. Set a size that will display the image without crowding out the browser controls or the rest of the Web
page elements. For example, to size a picture to fit one-fourth of the total screen area of a 13-inch monitor set to 640 ×
480 pixels, set the size at 320 pixels wide.
Also remember that older computer monitors have a resolution of only 72 dots per inch (dpi) while newer monitors
have a resolution of 96 dpi. So again, a high-resolution image does not necessarily mean a higher viewing quality on
computer monitors.
To size images for e-mail messages, the same principles apply, but remember that some e-mail services set a
maximum limit on the size of embedded or attached files. The larger the picture, the larger the file size. As a general
guideline, you can size images between 325 and 400 pixels wide, at medium to low compression, to have an
acceptably sharp image and size within an e-mail message.
8. Sharpen the image. In many image-editing programs, sharpening increases the contrast of pixels around the edges
of objects to increase the image definition or sharpness. Be careful not to overdo sharpening. Over sharpening
produces a white or light-coloured "halo" along highly contrasting edges, resulting in an over sharpened look. Since
tasks such as cloning objects into an image affect the edges in the final image, sharpening is best done as a last step.
More important, the original sharpness of an image is likely to diminish when the image is resized because the
program has to "guess" at which pixels to add or delete. So it's best to sharpen the image after all the retouching and
resizing are complete.
Also, the results of sharpening can vary between printed images and screen display. Experiment with your image-
editing program to see what amount of sharpening works best for printed images and on-screen images. If you are
going to print or output the same image to different destinations, make sure the sharpened image is a copy of the
original that has been scaled to the final output size. Remember, never sharpen the original image.
From Personal Experience
To make the most of your time in the digital darkroom, here is my personal advice:
* In a series of similar pictures, choose the picture with the best exposure, and work on it. Others in the series can be
ignored or worked on as you have time.
* Keep the original image open beside the image you're working on so you can track your progress and the changes
you make as you work.
* Have a well-corrected picture open or near the computer and refer to it as you work. It's easy to look at a picture so
long that you lose a "reference" point for the colour correction you want to achieve.
* Save your work often.
* Back up your pictures on CD or other removable, secure media often.
Additional tips
If your scanner or digital camera offers the option of viewing an image's histogram (a snapshot of the tonal range of an
image), you can tell from the histogram whether the image has enough detail in a given area to make computer
corrections. The y (or vertical) axis of the histogram shows the number of pixels assigned to any given brightness value.
The histogram shows shadow (darkest) pixels on the left, midtones in the middle, and highlight (lightest) pixels on the
right. The x (horizontal) axis shows the distribution of pixels from dark to light throughout the image.
A high-key, or light, image will have the highest level of pixels on the right. A low-key, or dark, image will concentrate
pixels toward the left. An average-key image will have the highest values toward the middle of the histogram. As you
shoot, check the histogram to ensure that you have a large area of detail and good distribution across the range to
make corrections later.
If your picture does not have a good tonal range, you'll generally want to edit the image to distribute the tones as evenly
as appropriate for the type of image you're working with.
Final advice
With this process, you should be well on your way to getting great images that you'll be proud to share and print. Keep
in mind that you can overdo adjustments so that the final image looks unnatural. When making adjustments, try to
remember the original scene, and then match your image to the colours and tonal range you remember. The first
pictures you correct will be the most time consuming, but as you get the hang of it, you'll find you spend less time at the
computer and more time shooting.
About the author: Charlotte K. Lowrie is the managing editor of editorial content for MSN Photos. Her writing and photography
have been published in magazines, including Quill (Society of Professional Journalists), Walking, and Texas Highways, and
newspapers, including the Dallas Morning News.
Text and photos by Charlotte K. Lowrie
Taking the picture is half of the fun of photography. The other half of the fun is in the digital darkroom—getting that great
finished image that you can't wait to show off to everyone who's willing to look at it. "Yeah, right," you say, "but I'm not a
professional, and I know nothing about editing pictures."
While digital image editing often mirrors traditional "wet" darkroom picture processing, you don't have to have traditional
darkroom experience to perform everything from minor fixes to minor miracles with digital images. And in many cases,
you can save pictures you would have otherwise thrown away.
Notice that I said "many," not "all" cases. Regardless of the small miracles you can perform, there will be some images
that no amount of computer editing will fix. Image-editing software is good, but, alas, far from perfect. For example, if the
detail is blown out of highlight areas, no amount of editing will put detail into the area. You can use a cloning tool to
paint in detail from a similar area, but the process is tricky, tedious, and the results often look artificial.
But, if you follow good darkroom process and practices, my bet is that you'll get more keepers than you thought
possible. And, what's more, you can polish those exceptional images into a portfolio of "personal best" pictures that
you'll be proud to share and print.
Following are tips and a suggested process for correcting digital images.
Before you start editing pictures
Regardless of how much fun image editing is, you don't want to spend time on the computer correcting something that
could have been corrected during shooting. Rather, ensure that you use your image-editing time to perfect and polish
good pictures instead of salvaging images that have problems because the white balance, ISO, or mode was
incorrectly set.
So the first two best steps in image editing begin before you sit down at the computer:
Learn your camera gear inside and out.
Use your camera correctly when you take pictures.
An important starting point when you begin editing on the computer is to know what you are correcting "to" or "for." In
other words, what does a well-corrected picture look like? The following list provides some of the basics for correcting
photos. Not every item in the list will apply to every picture, and, of course, there will be exceptions such as high visual
impact pictures in which many of the guidelines should be ignored, but you can use this list as a starting place for
image editing.
Good contrast. In general, contrast is the difference between light and dark areas in a photo. A low-contrast image
will seem flat and dull with little difference between light and dark areas. A high-contrast image will seem harsh and
may have little detail in the highlight and shadow areas.
Realistic colours. Image-editing may be necessary for images with excessive colour casts caused by inaccurate
white-balance settings on a digital camera or not using a colour correction filter on film pictures for different types of
lighting.
Natural skin tones. If people are in the image, images should accurately reflect natural skin tones.
Good saturation. Look for colour that is strong and accurate. Images with unnaturally vivid colours may be over
saturated. Likewise, images with washed out colour are under saturated and can often be corrected in an image-
editing program.
An appropriate level of image sharpness. Depending on the digital camera or scanning settings, images may or
may not be sharp. Some people set digital cameras and scanners to no or low sharpening, and do all the sharpening
in an image-editing program. In any case, correctly sharpened images display good detail in all areas of the image.
Over sharpened images appear to have too much contrast and may show digital noise as well. Soft images lack detail
in all areas of the image. Soft images typically result from setting the image quality level too low on the camera.
The image-correction process
For those new to image editing, the process of image correction generally follows a sequence of adjustments that build
upon each other. A simple example is sharpening. Sharpening sounds like a good starting point for image editing,
right? Not so. In an image-editing program, sharpening makes the image look sharper by increasing the contrast
where there are significant colour changes, such as the edges. If you sharpen an image first, and then make other
adjustments, such as burning (darkening an area) or dodging (lightening an area), the subsequent editing can create
unnatural-looking edges and pronounced halo effects around objects in the picture.
Following a sequence, or "workflow," in the digital darkroom not only helps you get the best results, but also ensures
that you work with a high-resolution copy of the image for as long as you can before making final edits such as
cropping or resizing for printing.
Image correction process
If you are shooting RAW images, some of the following steps may be done in the image-editing program that converts
the RAW images to TIF or JPEG format.
1. Rotate, save, and correct a copy of the original.
2. Adjust the tonal range (brightness and contrast).
3. Adjust the colour balance.
4. Dodge and burn.
5. Correct flaws such as dust, scratches, and red eyes.
6. Crop the image.
7. Save a copy and size the copy for printing, sending in e-mail, or posting on the Web.
8. Sharpen the image.
1. Rotate, save, and correct a copy of the original. Before editing an image, rotate it to the correct orientation if
necessary, and always save a copy of the original file in a "lossless" file format such as Tagged Image File Format
(TIFF or .tif) and work on the copy. Although you may have taken the image in JPEG format, do not edit and continue to
save the image in JPEG format. JPEG files are small because they are compressed to save space on the memory card
and on your computer's hard drive. However, during compression, some of the image data is discarded.
If you're working on a JPEG image and you periodically save it as a JPEG as you work, the image will be
recompressed, and bits of the image will be discarded each time you save the file. While you may not notice a
degradation in the image on the screen, the more you save a JPEG, the more its resolution will decline.
Instead, start by making a copy of the original image in a format such as TIFF. TIFF files are significantly larger than
JPEG because TIFF does not compress files, and it does not discard bits of the picture. For this reason, TIFF is
referred to as a "lossless" format.
Also, keep your untouched original images, in whatever format you took or scanned them, in a separate folder. That way
you can always go back to the original if image correction doesn't go the way you want.
Note: If you use layers to make adjustments on your picture, such as adding text, borders, and so on, you'll want to save
the image in the image-editing program's native file format. That way you can go back later and change individual layers
in the image if you want to.
2. Adjust the tonal range (contrast and brightness).
The tonal range of an image is the distribution from light to dark pixels within the image. In an average exposure the
tonal distribution will have a fairly even distribution of dark, midtone, and light pixels.
Most image-editing programs offer automatic and/or manual tonal-level adjustment tools. Using the automatic option,
the program typically chooses the lightest and darkest pixels and distributes the midtone pixels proportionally. This is a
generalized approach to tonal adjustment, and it usually works best on images that have average tonal ranges.
However, on overexposed or underexposed images, automatic tonal correction may not only over darken or over lighten
pictures, but it may also introduce unwanted colour shifts or tints.
First try the automatic tonal adjustment. If the adjustment isn't what you want, then adjust the tonal levels manually.
Tip: Try the automatic tone and colour adjustments first, because if the results are good, they can save time in
processing images. If you don't like the results, you can undo the changes and make the adjustments manually.
Another good starting point for tonal adjustment is to set the white point. Setting the white point maps the lightest pixels
in the image to white. Some image-editing programs allow you to set both white and black points. Setting the black
point maps the darkest pixels to black. When you set a white and/or black point, the program adjusts the intermediate
levels proportionally.
3. Adjust colour.
Before you adjust colour balance, evaluate the picture. If you are working on a sunset picture, adjusting the colour,
especially using an automatic colour-correction option, may remove the warm sunset colours—something you don't
want to do. If you determine that colour correction will improve the image, first try the automatic colour adjustment
options. If they don't produce the results you want, then undo the change.
If you make manual colour adjustments, you should know that in most image-editing programs, making a single
adjustment to a colour in the image will affect all of the colours in the image. And it's good to know that you can correct
colours using opposite colours. For example, you can increase the amount of a colour by decreasing the amount of the
opposite colour on the colour wheel, and vice versa. So to decrease a reddish cast in a picture, you can increase the
amount of green, its opposite colour. To make the sky more blue, decrease yellow, its opposite colour.
For general purposes, remember that the opposite of red is cyan (green/blue), the opposite of green is magenta (bright
pink), and the opposite of blue is yellow. Typically, very small adjustments can make a big difference. Watch the picture
to see how the adjustment is affecting the entire image as you work.
Depending on the image-editing program that you use, there can be one or many ways to adjust colour balance.
Tip
The hue, saturation, and brightness options are especially useful in restoring faded colours in old family photographs
you've scanned.
If your image-editing program allows you to make colour adjustments by individual channel, you can fine-tune colour
corrections by channel, a method many professionals swear by. Or, if your program offers an automatic colour-balance
option, you can try that. Keep in mind, though, that the automatic adjustment changes all colours in the image, not just
the ones you want to change. In other words, you may get more change than you wanted if you use the automatic option.
4. Dodge and burn.
In traditional, or "wet," darkrooms, standard image finishing includes darkening specific areas of the image by
increasing exposure (burning in) or lightening other areas by reducing exposure (dodging). Burning in areas often
reveals more detail or de-emphasizes less important or distracting areas. Conversely, dodging can reveal details in
overly dark areas.
Most image-editing programs have tools that give the same type of results on the computer that you get in a traditional
darkroom.
Regardless of which tools you use, it's a good idea to start with a low-intensity setting and to choose a brush size that
is smaller than the object you're working on. Also, always know the command or key combination to immediately undo
any changes you make.
5. Correct flaws.
Scratches, dust, and lens flare are only a few of the many flaws you can fix in an electronic darkroom. Some of the most
affordable image-editing programs automatically correct many of these errors. However, if you're willing to take the
time, many such errors are better corrected by hand.
The cluttered background is distracting. It draws the viewer's attention away from the subject.
One of the best tools for fixing flaws by hand is the cloning tool. It allows you to paint one part of the picture into another
part of the picture, or paint from one picture to another. For example, you can paint over unwanted elements such as
light poles, or add elements such as trees or people.
Tip
When you use a cloning tool, take care to produce natural-looking results. Use short strokes and click a new starting
position often. When you repeat the same starting point multiple times within an image, you are likely to create an
artificial-looking pattern.
Other guidelines include matching the angle of light and the proportions for cloned and original objects. In other words,
don't paint a shrub from a shadowed area into a bright area of the image, and don't clone a foreground area into
smaller background shrubbery.
Crop and size the image
6. Crop the image. Although some recommend cropping as one of the first steps in the image-editing process, I prefer
to crop later in the cycle. Very often I do not see the "best" crop until I've worked on the image for a while. Of course, you
can crop as one of the first steps, but always crop with care. The advantage of cropping is that you can discard portions
of the image that you don't want or that do not contribute to the composition. You can also focus attention on the subject.
The downside of cropping is that it reduces the overall size (and, therefore, the resolution) of the image, thus limiting
how much you can enlarge the image for printing. For this reason, it is always best to do as much cropping as possible
in the camera as you take the picture.
For example, if you crop out a third of an overall image, the resulting image may not have a high enough resolution to
print larger than 5" × 7". To do an 8" × 10" enlargement, the image must be at least 1536 × 1024 pixels. And it follows
that to get a poster-size enlargement, it's a good idea to avoid cropping the original image at all.
7. Print, e-mail, or create a copy to post on the Web.
Assuming that by now you have a flawless version of a picture, you can make copies of the final image and size each
copy for the medium in which you want to print or display it.
If you choose to have the image printed professionally, the following table provides the minimum image dimensions
needed for each print size.
Print size (inches) Min. width (pixels) Min. height (pixels)
4 × 6 800 600
5 × 7 1050 750
8 × 10 1536 1024
11 × 14 1750 1375
16 × 20 (poster) 2500 2000
18 × 24 (poster) 2500 2000
24 × 36 (poster) 2500 2000
30 × 40 (poster) 2500 2000
36 × 48 (poster) 2500 2000
For use in e-mail or on the Web
The size you choose for images displayed on a computer screen is determined by the size, settings, and resolution of
the monitors on which the image will be viewed (unlike for images you are printing). It is important to make sure that the
pixel dimensions of your image are no larger than absolutely necessary for comfortable viewing. The only result of
making a file any larger than necessary is slow download times or rejection by the receiving e-mail server.
People can change the resolution of their monitors to just about any of the following resolutions, regardless of the size
of their monitors. However, for best readability of text, monitors most likely are set at a given resolution based on the
size of the monitor. For example, monitors in the 12-inch to 14-inch range generally display 640 pixels horizontally and
480 vertically (640 × 480). Fifteen-inch to 17-inch monitors are generally set to 800 × 600 pixels. Nineteen-inch
monitors generally display 1024 × 768 pixels. Larger monitors can display different numbers of pixels, such as 1280 ×
1024 pixels.
If you have a Web site, and you size an image as 640 × 480 pixels, the image will fill the screen of a 13-inch monitor.
Likewise, it will fill the screen of a 15-inch monitor that is set at 640 × 480; however, the pixels—and therefore the
image—will appear to be larger on the 15-inch monitor than on the 13-inch monitor. But if the 15-inch monitor is set at
1024 × 768 pixels, the pixels that make up the image—and therefore the image itself—will appear smaller.
Today, Web designers generally plan for a screen size of 800 × 600 pixels as the most common denominator, which
works for most monitors.
To size an image for online display, make a copy of the finished image, and then change the size of the copied image
to fit the screen. Set a size that will display the image without crowding out the browser controls or the rest of the Web
page elements. For example, to size a picture to fit one-fourth of the total screen area of a 13-inch monitor set to 640 ×
480 pixels, set the size at 320 pixels wide.
Also remember that older computer monitors have a resolution of only 72 dots per inch (dpi) while newer monitors
have a resolution of 96 dpi. So again, a high-resolution image does not necessarily mean a higher viewing quality on
computer monitors.
To size images for e-mail messages, the same principles apply, but remember that some e-mail services set a
maximum limit on the size of embedded or attached files. The larger the picture, the larger the file size. As a general
guideline, you can size images between 325 and 400 pixels wide, at medium to low compression, to have an
acceptably sharp image and size within an e-mail message.
8. Sharpen the image. In many image-editing programs, sharpening increases the contrast of pixels around the edges
of objects to increase the image definition or sharpness. Be careful not to overdo sharpening. Over sharpening
produces a white or light-coloured "halo" along highly contrasting edges, resulting in an over sharpened look. Since
tasks such as cloning objects into an image affect the edges in the final image, sharpening is best done as a last step.
More important, the original sharpness of an image is likely to diminish when the image is resized because the
program has to "guess" at which pixels to add or delete. So it's best to sharpen the image after all the retouching and
resizing are complete.
Also, the results of sharpening can vary between printed images and screen display. Experiment with your image-
editing program to see what amount of sharpening works best for printed images and on-screen images. If you are
going to print or output the same image to different destinations, make sure the sharpened image is a copy of the
original that has been scaled to the final output size. Remember, never sharpen the original image.
From Personal Experience
To make the most of your time in the digital darkroom, here is my personal advice:
* In a series of similar pictures, choose the picture with the best exposure, and work on it. Others in the series can be
ignored or worked on as you have time.
* Keep the original image open beside the image you're working on so you can track your progress and the changes
you make as you work.
* Have a well-corrected picture open or near the computer and refer to it as you work. It's easy to look at a picture so
long that you lose a "reference" point for the colour correction you want to achieve.
* Save your work often.
* Back up your pictures on CD or other removable, secure media often.
Additional tips
If your scanner or digital camera offers the option of viewing an image's histogram (a snapshot of the tonal range of an
image), you can tell from the histogram whether the image has enough detail in a given area to make computer
corrections. The y (or vertical) axis of the histogram shows the number of pixels assigned to any given brightness value.
The histogram shows shadow (darkest) pixels on the left, midtones in the middle, and highlight (lightest) pixels on the
right. The x (horizontal) axis shows the distribution of pixels from dark to light throughout the image.
A high-key, or light, image will have the highest level of pixels on the right. A low-key, or dark, image will concentrate
pixels toward the left. An average-key image will have the highest values toward the middle of the histogram. As you
shoot, check the histogram to ensure that you have a large area of detail and good distribution across the range to
make corrections later.
If your picture does not have a good tonal range, you'll generally want to edit the image to distribute the tones as evenly
as appropriate for the type of image you're working with.
Final advice
With this process, you should be well on your way to getting great images that you'll be proud to share and print. Keep
in mind that you can overdo adjustments so that the final image looks unnatural. When making adjustments, try to
remember the original scene, and then match your image to the colours and tonal range you remember. The first
pictures you correct will be the most time consuming, but as you get the hang of it, you'll find you spend less time at the
computer and more time shooting.
About the author: Charlotte K. Lowrie is the managing editor of editorial content for MSN Photos. Her writing and photography
have been published in magazines, including Quill (Society of Professional Journalists), Walking, and Texas Highways, and
newspapers, including the Dallas Morning News.
This picture has many of the elements you
look for when editing images; a good tonal
range, vivid colours, white whites, black
blacks and detail in the shadow areas.
look for when editing images; a good tonal
range, vivid colours, white whites, black
blacks and detail in the shadow areas.
Tone and colour
adjustments made this
colour and contrast.
adjustments made this
colour and contrast.
Careful correction can make the difference between
an image being a throwaway or a keeper.
an image being a throwaway or a keeper.
In this image the water has a
greenish colour cast and the visual
impact is diminished by the
wide-angle view.
greenish colour cast and the visual
impact is diminished by the
wide-angle view.
This original image was
too dark overall.
too dark overall.
Setting the white point was the starting
point for making tonal corrections to this
image. Be sure to click the lightest white in
the picture when you set the white point.
point for making tonal corrections to this
image. Be sure to click the lightest white in
the picture when you set the white point.
Although it may be difficult
to see at this size, adjusting
the colour balance creates
more realistic colour casts
for both the sky and the
water.
to see at this size, adjusting
the colour balance creates
more realistic colour casts
for both the sky and the
water.
Although vivid colours are
good, you can go too far.
For example, this image is
unnaturally blue.
good, you can go too far.
For example, this image is
unnaturally blue.
In this image, I used dodging
and burning to minimize
distracting reflections that
appeared in the man's
sunglasses.
and burning to minimize
distracting reflections that
appeared in the man's
sunglasses.
The cluttered background is
distracting. It draws the
viewer's attention away
from the subject.
distracting. It draws the
viewer's attention away
from the subject.
I cropped the image and
cloned out the background
distractions.
cloned out the background
distractions.
An unsharpened image.
| Sharpening improves the image. |