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Helen Bradley - Photoshop and Lightroom tips and techniques

I'm Helen Bradley - I'm a photographer and Photoshop professional. In this Photoshop and Lightroom blog you will find powerful Photoshop and Lightroom tips, tricks and techniques that will help you get more out of both programs. You will also find step by step guides for working creatively with your photos in Lightroom and Photoshop and any other cool applications I know you will be interested in knowing more about.

Friday, June 26, 2009

Photoshop Elements: Spot sharpening with a faux layer mask



One of the features on the wish list of most advanced Photoshop Elements users is Layer Masks. It is one of the key features that separates Photoshop Elements from Photoshop - but it doesn’t have to be that way. It is possible to create faux layer masks in Photoshop Elements if you know how – and today, I am going to show you how.

One of benefits of this approach to creating faux layer masks in Elements is that it uses features built into Elements and it doesn't rely on a third party plug-in so it works with most versions of Photoshop Elements.

A bit of background
While Photoshop Elements doesn't support layer masks for regular layers, it does provide them for all its adjustment layers. This faux layer mask solution takes advantage of this by forcing an adjustment layer's layer mask to behave like a layer mask on a regular layer just as it does in Photoshop. The trick is to apply an adjustment layer to the image which does nothing to the image at all – so you get the benefit of the layer mask but without forcing any unwanted change on the image. Once you've done this you have a layer mask you can borrow.

In this step by step example, I'll show you how to use the mask to paint some additional sharpening onto an image. What I'll do is oversharpen an image – well beyond the level of sharpening which the image should have and then I'll remove the sharpening with the mask and paint is back over selected parts of the image – again using the mask.

While this technique is shown using Photoshop Elements you can use the same technique in Photoshop – only in Photoshop you won't need to use the fake mask as you can add a layer mask to the oversharpened layer itself.


Step 1
Finish editing your photo. If you have multiple layers, create a flattened version of image by selecting the topmost layer and press Ctrl + Alt + Shift + E (Command + Option + Shift + E on the Mac). This creates a new composite layer without flattening the layers.

Duplicate this layer by right-clicking it and choose Duplicate Layer. You should now have two identical image layers at the top of the layer stack.


Step 2
Select the topmost layer and choose Enhance > Unsharp Mask and apply excessive sharpening to the image. What you want is an extremely oversharpened image. You don’t want halos, just very heavy sharpening. In this example, I’ve used a radius of 2, a threshold of 0 and the full amount of 500. Click Ok.


Step 3
Add an adjustment layer by choosing Layer > New Adjustment Layer and choose either Levels or Brightness/Contrast or Hue/Saturation – you need an adjustment layer that doesn't do anything to the image if you don't alter its settings. Click Ok and don't make any changes to the adjustment layer settings. Drag the adjustment layer so it sits between the two image layers.


Step 4
To create the fake layer mask, select the topmost oversharpened layer and choose Layer > Group with Previous. This attaches the oversharpened layer to the adjustment layer below limiting the effect of this layer to the area that is white in the adjustment layer mask – right now that is all the top layer.


Step 5
Click on the adjustment layer and click on the layer mask thumbnail which is the white box on the right side of the layer in the Layers palette. You should see a double border around it indicating that it’s selected. Fill this mask using the paint bucket tool with black. The entire oversharpening effect is immediately removed from the image.


Step 6
Select the brush tool and select a soft round brush. Adjust the opacity to around 25 percent and select white as the foreground color. With the layer mask thumbnail still selected, paint over the areas of the image that you want to apply additional sharpening to. In my case, I wanted to oversharpen the eyes on the orangutan.


Step 7
As you paint, the sharpening effect will built up – if you paint somewhere by mistake, set black as the foreground color and paint out the mistake. This is how a mask works - you paint with black to remove the effect on this layer (in our case you paint in black to remove the sharpening effect form the layer above because the two layers are grouped together) and you paint with white to reveal the effect.

When you are done, you can flatten the image or save it as a layered PSD file.

In future whenever you need to use a layer mask in Photoshop Elements, simply apply an adjustment layer to the image, drag it under the layer it should control and group the layers together.

Learn more: If you're interested in learning more about sharpening, check out my very popular post on Understanding the basics about Sharpening.

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Sunday, June 07, 2009

Understanding the basics of Sharpening in Photoshop



Sharpening is one of those everyday tasks that most photos can benefit from. In this post I'll explain what sharpening is, when you should perform it and how to do it. The information here, although it is explained using Photoshop, is relevant to all photo editing programs.

Sharpening does as its name suggests and sharpens the image making it look crisper and making the edges in the image more distinct.

In the darkroom the process is achieved by taking one negative and a slightly blurred positive image, sandwiching these together and making a very quick exposure of this sandwich. Then the exposure is completed using the negative. The resulting image has sharper and crisper edges than it would have had if the blurry (unsharp) mask image had not been used. The typical sharpening tool used in Photoshop and other graphics programs is named after this traditional darkroom process and is called the Unsharp mask.

In a graphics editor the Unsharp mask works by creating small halos along the edges in the photo. These halos enhance the contrast between the edges and the surrounding pixels making the edges look more obvious and giving the image a crisper and sharper look.

Here’s how to sharpen an image using the Unsharp mask:


Step 1
Sharpening should be done at the end of the editing process so finish doing all your edits to the image before you sharpen it.

Now create a flattened version of the image either by flattening or merging all the layers or press Ctrl + Alt + Shift + E (Command + Option + Shift + E on the Mac) to create a flattened layer at the top of the image. The Unsharp mask works only on the current layer so you need to have the image on a single layer for it to do its work.


Step 2
Choose Filter > Sharpen > Unsharp Mask. Set the Radius to somewhere between .5 and 1. This sets the width of the halos which are applied along the edges in the image – the smaller the radius, the smaller the halo and 0.5 – 1 is ideal – this is not always a situation where the more is better!

Set the Threshold to around 10. The Threshold value determines how edges are found – the higher the value, the more different adjacent pixels must be to be considered an edge so less of the image will be sharpened. A small value means that smaller differences in pixel values are considered an edge so more of the image is sharpened. The risk with a small Threshold value is that it can add noise to the image by enhancing edges in places where you don't want to see them.

The Amount setting controls how much contrast is added to the edges – a higher value means more contrast and a more obvious sharpening. Start by setting this value to around 150.



Step 3
Take a look at your image and adjust the sliders from this starting point until you see more detail in the edges in the image but not so much that you see unattractive halos around the edges.

Typically, if you have an image with a lot of very fine detail you can use a very small radius value (so the halos are small) and a correspondingly high Amount value (so that the halos can be seen to sharpen the image). On the other hand, if you have an image without a lot of fine detail can use a larger radius say, 1 – 1.5 or more (which gives larger halos), and a smaller Amount setting because the halos will be bigger and more visible anyway.

Adjust the Threshold value so you get sharpening in the areas you are interested in being crisper but not so that it results in unwanted noise in the image.


This image is nicely sharpened – you can see the crisper edges.


This image is over sharpened – notice the unsightly halos around the edges.

Tips
It is generally advisable to view the image at 100% when you are sharpening it so you can see the effect on the image. You can do this by sizing the image to 100% before launching the Unsharp mask tool. Alternately, use the 100% preview in the Unsharp mask dialog –click on the preview to see the unaltered image so you can compare it with the preview..

When you are sharpening for printing you can generally sharpen more heavily than you should do for onscreen viewing.

There are other sharpening tools available in Photoshop CS2 and later which do an even better job of sharpening than the Unsharp mask. I'll look at these tools in a future post. For now, regardless of which graphics editor you use, you should have an Unsharp mask tool and it should work in a similar way to the Photoshop Unsharp mask shown here.

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Monday, May 11, 2009

Lightroom: Spot fixing with the Adjustment Brush



One of the exciting new features in Lightroom 2 is the adjustment brush which lets you to make spot fixes to your image in Lightroom. These fixes apply to only the area you select rather than the entire image. This means you can make local adjustments for contrast, saturation, exposure, brightness, clarity and sharpness without having to take the image to Photoshop to do this.

In this post I'll show you how to get started using the adjustment brush in Lightroom. 2


Step 1
Open Lightroom and click the Develop module. Locate the Adjustment Brush and click it to select it. Hold the brush over the image to check its size. The inner circle is the hard part of the brush and the outer circle shows the edge of the feathering. To adjust the brush size use the [ and ] keys or adjust the Size and Feather using the sliders.



Step 2
Select the adjustment to make, such as Brightness or Saturation by clicking its + symbol to increase its value or the – symbol to decrease it. Then start painting on the image to adjust that part of the image. When you start painting the effect onto the image, Lightroom places an identifying marker on the screen. Here I have Brightness selected and the marker is visible.



Step 3
If you don't know where you have painted – and it's often very hard to know exactly - press the O key to view or hide a mask which shows the area you have painted on. If you prefer to, you can display the mask as you work. The mask also appears if you hold your mouse over the marker.

To erase the brush strokes, click the Erase option in the brush area and erase over the area to remove the strokes. To return to painting click brush A which is the default brush and continue to paint over the area. You can also use the brush with the Alt (Option on the Mac) to remove the painted areas rather than switching between the brush and eraser.



Step 4
If the effect is too much or too little you can adjust the intensity of the effect using the slider.


Step 5
If another area of the image requires fixing, click the New option and then repeat the steps to select a fix and then paint it onto that part of the image. Later on you can adjust either of the fixes by first clicking the Adjustment Brush tool to select it and then click on the marker for the area to change – you will see that the word Edit is now highlighted - and you can now adjust the painted area or adjust the amount of the fix.

In a future post I will look at some more advanced functions of the Adjustment Brush.

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Tuesday, March 03, 2009

Sharpening in Lightroom 2



Sharpening is the last step in editing an image. If you're working in Lightroom then you have a very sophisticated Sharpening tool at your disposal. It's hard to determine what the coolest part of the process is - the Detail and Masking sliders or the fact that sharpening is applied to only the image luminosity so it doesn't mess up the image colors.

To sharpen in Lightroom, open the Develop module and the Detail panel to show the sharpening tools. A good starting point for most images is to set the Amount to 100, set the Radius to 1.0 and the Detail to around 25. As an aside, it's nice to see that Lightroom is realistic about the appropriate radius to use and it limits you to a value between 0 and 3 which takes some of the guess work away from determining what value you should use.

Now you have a starting point, adjust the Detail and Amount sliders to see how they affect the sharpening. To see the before and after, press the backslash (\) key. The Detail slider is unique to Lightroom - it doesn't appear in Photoshop. What it does is to remove halos around the sharpened edges. Low values for Detail reduce halos and higher values allow them.

The Masking slider is a way cool tool. It lets you remove the sharpening from texture areas of the image and areas that you typically would not want to be oversharpened such as skin tones. To use it, drag the Masking slider to around 75 and compare the results. You should see less sharpening in areas that don't typically need it the larger the Masking value. To see what the mask looks like, hold the Alt key (Option on the Mac) as you drag on the slider and you'll see a grayscale mask in place of your image. The white areas of the mask are the areas that will be sharpened - they are the edges in the image - and the black areas are those that will not be sharpened or which will be sharpened with less intensity.



The mask gives you a lot of control over how the sharpening is applied to the image and it prompts the question "why isn't this in Photoshop too?"

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Wednesday, February 25, 2009

Photoshop: Fixing photos shot from airplanes



One of the cool things about getting a window seat in an airplane is that you get a unique opportunity to photograph things from a high vantage point. On the flipside, when you get them home you often find photos taken from the air look washed out and the colour is poor. Luckily there is not much that Photoshop can’t recover provided the photographs are in focus. So if you scored a window seat lately and if you have images that fix, I'll show you the Photoshop tools you need to fix them.

Understand the problems
Most airplane photos look washed out and they don’t have the richness of colour that you might expect them to have. The first step in fixing them is to boost the tonal range in the image using a levels adjustment - a by product of this is that the colour gets a boost.

Step 1
Start by making a duplicate of the background layer so that you're working on a copy in case you need to refer to it later on. To do this, right click the background layer in the layers palette and choose Duplicate Layer.



Step 2
Select the background layer and choose Layer > New Adjustment Layer > Levels and click Ok. The Levels histogram tells you a lot about the state of your image. In most cases you’ll lack white whites and black blacks and most of the image content will be around the middle of the image. Drag the right and left sliders below the chart so that there are below the points where the chart data begins. This should give the image an immediate boost in contrast and some boost in colour too. Adjust the midtone slider if desired to fix the midtones in the image and click Ok to confirm your settings.




Step 3
Colour fixes: Often the image will contain too much blue and you can adjust this using a Curves adjustment. Choose Layer > New Adjustment Layer > Curves and click Ok to display the curves dialog. Click the Channel list and choose the Red channel. Drag up on the middle of the Red channel line to add some red to the image. Repeat with the Green channel adjusting it as required – drag down on the middle to remove green and up to add it. Finish with the Blue channel.

If you’re unsure which way to go with the adjustment, give the line a good pull in one direction or the other to see what happens, back off the adjustment to get something less intense. Different places on the curve line will give you different effects so experiment either side of the midline. Click Ok when you are done.

Step 4
Fixing uneven contrast: Photographs shot from high up are generally display better tonality in the areas closer to you and poor tonality in areas farther away. To fix this add another layer by choosing Layer > New Layer and click Ok. Fill this layer with a gradient by selecting the Gradient tool and select the Black to White gradient. Choose the Linear option and drag the gradient to fill the layer. You want black at the top of the layer and white at the bottom – if you get it wrong, drag in another direction till you get it right. Don't worry that your photo has disappeared in the process!

From the Blend modes dropdown list choose Color Burn. This will darken the image considerably particularly in the areas where the black colour appears. Adjust the layer Opacity in the layer palette until you get an acceptable result.

Step 5
Final touches: To finish the colour fixing, boost the saturation using Layer > New Adjustment Layer > Hue/Saturation and increase the Saturation a little. If the image needs a little lightening and if you're using Photoshop CS3 or CS4, use a Brightness/Contrast adjustment layer. If you're using Photoshop CS2 or earlier, use a Curves adjustment and this time drag the composite RGB curve upwards to lighten the image. The Brightness/Contrast tool in earlier versions of Photoshop is to be avoided at all costs as it damages good pixels in the image - the new tool that first appeared in Photoshop CS3 is much different and much better.

step 6
Sharpening: The final step is to apply some sharpening to the image. To do this, you need a single image layer so press Ctrl + Alt + Shift + E to create a composite layer. Select this layer and use Filter > Sharpen > Unsharp Mask to sharpen the image. Set the Radius to between 0.5 and 1 and set the threshold to under 10. Adjust the Amount until you get a good sharpening of the image.

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