Removing Flash Hot Spots in Photoshop

Following on from my recent children’s photography feature in Photo Pro I’m really happy to have been asked to write a series of portrait retouching tutorials for the magazine. I know there’s quite a few overseas photographers who read my blog and are unable to get the magazine so I thought I’d post the tutorials here as they come out. I’ve written the first four already but if there’s anything particular you’d like me to write a tutorial on then please feel free to email me or leave your suggestions in the comments. Anyway, to the first tutorial…

One problem area you may have encountered while retouching portraits are those overly bright areas of skin known as hot-spots. There are a variety of different ways to tackle this kind of problem in Photoshop but I’ve found that this technique gives me the most natural looking results. It’s also completely non-destructive, retains the original skin texture and can be achieved with one layer.

1. As you can see, the ring-flash used to shoot this image has left quite a few overly bright areas on both modelʼs faces – especially on the male modelʼs cheek and around his nostril. I donʼt want to get rid of these hot-spots completely as the highlights add depth and dimension to their faces, I just want to reduce them.

2. Create a new blank layer and name it. Weʼll be using the healing brush directly onto this layer so make sure you have the healing brush tool set to sample the ʻcurrent layer & belowʼ. This is available in the Options bar at the top of your screen when you have the healing brush tool selected.

3. Remove all traces of the hot-spots with the healing brush, making sure to sample from areas of similar ʻgoodʼ skin. Donʼt worry if the skin looks flat and unnatural, weʼll fix this with a mask in the next step.

4. Calculations is one of the most powerful masking tools in Photoshop and probably one of my most used features. Wherever possible I always try to create layer masks based on the tonality of the image itself and Calculations allows me to do this very easily.

In this particular image I want the mask to reveal the healing layer on the brightest part of the skin and fade out into darker areas of good skin. In terms of a mask weʼre looking for the hot-spots to be as light as we can get them (white reveals the healing) and the rest of the skin to be as dark as possible (black conceals the healing). Turn the healing layer off so you can see the hot-spots and go to Image > Calculations.

Combining the Blue Channels with a blending mode of Multiply seemed to give me the best contrast between the hot-spots and the rest of the skin. Set the ʻResultʼ to give you a selection that you can use to create your mask.

5. With your selection active, turn on the healing layer.

6. Create a mask from your selection by going to Layer > Layer Mask > Reveal Selection or clicking the little ʻAdd layer maskʼ icon at bottom of layers palette. With the mask active your image should look a lot more natural, but Iʼd still like to bring a little more detail back in the skin.

7. Even though it looks pretty good with the mask adding some nice shape and dimension to the healing layer, I think it could still benefit from bringing back a few highlights in the skin. I could just lower the opacity but this would effect the whole layer and Iʼd like a little more control over the effect. Go to Layer > Blending Options or double click to the right of the layer name to bring up the Layer Styles dialog box.

At the bottom of the Layer Styles dialog box youʼll see the Blend If options. Blend If allows you to selectively blend the current layer and the layer below based on areas of brightness or colour in the layers.

8. If you move the white slider on the ʻThis Layerʼ section to the left you can drop out highlights or whites in the active layer, letting the corresponding area in the underlying layer show through. if you move the white slider to the left on the Underlying Layer section you can force the lightest areas in the layer below show through over the current layer. The black sliders work in exactly the same way but target the darker areas of an image. I used the ʻThis Layerʼ slider as it seemed to give me the best results.

I also want the transition into the bright pixels to be as smooth as possible so Option (Mac) or Alt (PC) click the white slider in “This Layer” and drag to the left. This will split the slider into two halves. Splitting the slider allows you to make a softer transition, very similar to feathering a selection. The further left you drag the split slider the more bright pixels from the layer below show through giving you a huge amount of control over the effect.

9. In the final image you can see that the hot-spots are still visible but have been substantially reduced and the texture of the underlying skin is still intact.

Before:

After:

Image courtesy of Carlos Amoedo.