The magazine of the Melbourne PC User Group Creating Gorgeous Web Photos Helen Bradley © |
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Do you look at photographs on the web and think that your own photos suck? Helen Bradley says all that separates their images from yours is a few minutes in Photoshop. |
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It's not difficult to transform your photos into images that look brighter, crisper and have better colour and I'll show you the secrets of doing this. One proviso before we begin. No matter how good you are in Photoshop, you still have to have a good image to work with. The photo needs to be well composed, in focus (where it should be and not where it shouldn't be), and correctly exposed. One feature that good photos share, particularly portraits, is that they're generally captured using a digital SLR camera with a portrait lens or zoom with a large aperture setting of somewhere around f1.4 - f3.5. These lenses help you capture an image with a shallow depth of field - this is the area around the subject that's in focus. When capturing portraits such as a coach in front of his players, or a person in a crowd, it's ideal if you can isolate the person so they're in sharp focus and the remainder of the image in front and behind them is in soft focus or completely out of focus. This effect is difficult to mimic using a point-and-shoot camera, as these can't usually achieve the depth of field that you'll get from an SLR. When shooting with an SLR lens that has a large aperture like this, you must ensure that your subject is in sharp focus. The small depth of field won't give you much margin for error. However, the benefit of capturing an image with a shallow depth of field is that the viewer's eye goes immediately to the sharpest, shiniest and brightest area of the image which, if the rest of the image is out of focus, is your subject. |
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Photoshop fixes
Most of the images I shoot and display on the web are tweaked before being
uploaded and I'll show you how I work. I'm not going to cover basics like
cloning- out problems, fixing colour casts, fixing red eye or blemishes - these
should be fixed beforehand.
What I will show you are some fixes that punch colour and contrast and make
even lacklustre
images look just wonderful. These are big ticket fixes, they're straightforward
and most photos can be improved by using them. However, take care when using
the LAB correction on portraits. Skin tones are more sensitive to the strong
colour fix I'm about to show you than almost anything else. Always work
on a duplicate of your photo - not the original.
The first fix to use is a Curves adjustment - I
like this more than Levels as you get more control
over what gets fixed. A Curves adjustment lets you improve the tonal range of
the image - the darks get darker and the lights get lighter and, in doing so,
you'll generally find colours get more saturated.
Always duplicate the background layer in the image before starting by choosing
Layer, Duplicate Layer. Now, select Layer > New Adjustment Layer > Curves and
click Ok. When the Curves dialog
appears drag the markers which are under the chart inwards until they meet the
edges of the chart.
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This instantly improves the overall tonal range of the image. If your Curves
chart doesn't have these markers under the chart, go back and create a
Levels Adjustment Layer first and drag those markers inwards under either end
of the chart. Then add a curves adjustment layer and continue from here.
Another fix you can apply with curves is to drag a shallow S shape into the
curve by dragging on it with your mouse to shape it. Typically an S shape curve
will lighten the lights and darken the darks in the image and add more variety
to the midtones.
To add even more value to the Curves adjustment, work out what part of the
curve needs fixing. To do this, left click and move your mouse over the area of
the image that you want to add some contrast and variety to. When you do this,
you'll see a little marker running up and down your curve line -
this shows you where on the curve these colours appear. This is the part of the
curve you need to steepen - the steeper the curve at this point, the more
variety you'll get in this portion of the image.
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The best way to approach the task is to put a marker on the curve just above
and just below the area of interest - these hold the rest of the curve in place
so it won't move a lot. Now drag on the curve between the markers to adjust
that area of the curve - dragging upwards will lighten that area and dragging
downwards will darken it. Another way of approaching Curves is to adjust only the channels which lack contrast. Check the Channels palette and look at the Red, Green and Blue channels one at a time. Identify those which lack contrast. Then, add a Curves adjustment layer, select the channel and apply your curve adjustment to that channel alone. The unsettling side effect to this is that you'll totally foul up the colours in the image - don't worry, I promise we'll put them back in the next step. All you're looking for here is more contrast in the image. When you're done, set the layer blend mode of the adjustment layer to Luminosity. This applies the fix to the luminosity values in the image not the colour so the ghastly colour disappears but the tonal range is vastly improved. In addition, because you did this using an Adjustment layer you can double-click it to edit it if you think you need more or less of the fix. Or you can vary the adjustment layer opacity to blend it into the layer below. |
Dragging colour out kicking and screaming
This next fix is not for the faint of heart - however once you've experienced
its power, I guarantee you'll never look at colour the same way again. The fix
involves using LAB colour space - you don't need to know much about it except
that it separates colour from Lightness which RGB doesn't. LAB images have
three channels - Lightness, a and b. The a channel is green/magenta, the b
channel is yellow/ blue and the L channel is lightness. Get it? L a b.Before you go to LAB, you must flatten any adjustment layers as these
adjustments won't survive the trip to LAB Colour. Click the adjustment layer
and choose Layer > Merge Down. Then, when your
image has no more adjustment layers, duplicate the top image layer so you have
two copies of it.
Choose Image > Mode > LAB Color to move into LAB Color mode. Select the Don't
Flatten option. Choose Image > Adjustments > Curves - avoid using an adjustment
layer here since you'll have to flatten it anyway before you go back to RGB. If
desired, select the Lightness channel and drag a shallow S shape curve into the
Lightness channel. This fix affects only the lights and darks in the image and
has no effect on the colour.
To adjust the colour choose the a channel and drag the top-right and
bottom-left ends of the chart horizontally inwards an equal number of squares
from the left and right edges of the grid.You can do this one, two or three
squares but you must do the
same to each end of the chart so the line still crosses the middle of the
chart, or you'll get a colour cast. What you want is a hefty change in the
image colour. Err on the side of getting more than you need.
Repeat this fix for the b channel, again moving both ends of the chart
horizontally inwards the same number of squares. Click Ok.You can now tone down
the effect by adjusting the opacity of the top layer so the unfixed layer below
shows through. Return to RGB mode by choosing Image > Mode > RGB and select
Don't Flatten.
Crop, Size, Sharpen and Compress.
Crop the image to isolate the area of
interest - most images can take quite severe cropping and will be all the
better for it. Size the image using Image > Image Size to the width and height
desired for the web, set the Resolution to 96 pixels per inch and choose
Bicubic Sharper as the Resample algorithm.
Click OK. Sharpen the image using the Unsharp Mask - for web display don't
over-sharpen
the image - you need a lot less sharpening for the web than you need for
printing.
To save the photo for use on the web choose File > Save for Web and Devices and
optimise the image using the dialog settings. Photos
should be saved as JPEG images and can usually stand compression values of
around 60 without sacrificing too much quality. Check the image size and
download times below the image to get an idea as to whether you're getting the
size down sufficiently for your purpose - you need a lot more image and quality
for printing than you need for web display.
These fixes sound like a lot of work but once need for web display - this is
much smaller than for printing
you're familiar with the process and the tools, you can turn an image around in
a minute or two. The Curves adjustment is a must do for almost all images and
when you'd like a colour boost, the LAB fix is well worth checking out.
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Note: Helen Bradley © Permission to copy or quote
extracts from this article may only be done with the written permission of the
author.
Reprinted from the September 2008 issue of PC Update, the magazine of Melbourne PC User Group, Australia
