How to fix shiny skin in photos, and when you cannot

What shine actually is

Skin returns light two ways. Most of it scatters under the surface and comes back as the diffuse colour you think of as skin tone. A small part bounces straight off the surface film without going in, and that part carries no skin colour at all. It carries the colour and, crucially, the shape of whatever lit it.

So a shiny forehead is a picture of your light source. That explains the thing people find confusing, which is why shine looks fine some days and greasy on others with the same face. A large soft source, such as a window on a grey day, produces a broad gentle highlight that reads as healthy sheen. A small hard source, such as a bare bulb, a phone flash or the sun, produces a small intensely bright spot that reads as grease. The oil on your skin did not change. The lamp did.

Two things follow. The first is that the fix in editing is a brightness and colour fix, never a blur. The second is that the fix at capture is to change the size or the position of the light, which is faster and works on every frame at once.

The test for whether it can be fixed

Before you spend five minutes on a highlight, find out whether there is anything under it. Zoom in on the brightest part of the patch and either look at the histogram or temporarily push saturation to the maximum.

If the patch takes on a pink, yellow or orange cast when you crank saturation, the detail is still recorded. Undo the saturation and go to work, because it will come down cleanly.

If it stays flat white at full saturation, all three colour channels are at their ceiling and the file holds no information there at all. It is clipped. Reducing exposure on clipped pixels produces grey, not skin, and on a forehead that grey patch is more obvious than the shine was. At that point you have three honest options: accept it, clone skin over it and accept a flat area, or use a different frame.

This is worth knowing before you shoot, too. Highlights clip first and they clip permanently, which is why exposing a face slightly down under hard light is safer than exposing it up. Shadows can be lifted. Blown highlights cannot be un-blown.

Bringing a hot patch down

Work in this order and stop as soon as it looks like skin.

Global Highlights first. Pull Highlights down 20 to 40 and see what comes back. On a photo where the shine is the only bright thing, this alone often finishes the job, and it takes one slider.

Go local if the rest of the photo suffers. If dropping Highlights globally kills a bright window or dulls the whole image, undo and brush instead: Exposure down 0.3 to 0.7 stops over the patch, Highlights down within the same brush, feathered generously.

Put the colour back. This is the step everyone misses. A bright patch of skin is not only brighter, it is less saturated and usually cooler, because the specular reflection carried no skin colour. Reduce the brightness alone and you get a grey smudge. Within the same local adjustment, add a few points of saturation and a touch of warmth until the patch matches the skin next to it.

Match the edge. Real shine fades gradually. A hard-edged brush leaves a visible disc on the forehead, which is worse than the original. Keep the feather wide and the strength low, and build it up in two passes rather than one.

Where the tool lives in each app

Snapseed's Dodge and Burn brush is the free tool most people should reach for here, because burning a highlight down is precisely what it was built to do, and unlike a healing tool it never touches texture.

Leave some of it

The common mistake is not leaving too much shine, it is removing all of it. A face with no specular highlight anywhere reads as matte, and matte does not read as skin. It reads as a mask, or a mannequin, or a render, which is exactly the uncanny quality people blame on smoothing when the real cause is a flattened highlight.

Three highlights are worth protecting: a small one on the top of each cheekbone, one on the tip of the nose, and a wet one on the lower lip. Those three are a large part of how a viewer reads a face as three dimensional and alive.

What to reduce is the broad hot area rather than the small bright points: the band across the forehead and the T-zone between the brows, both of which come from an overhead light and neither of which describes the shape of the face. Bring those down until they sit close to the brightness of the cheek, and leave the points alone.

The test is to look away for ten seconds and look back. If the face has gone flat, you took a plane out of it rather than a reflection.

Fixing it before the shutter

Every one of these is faster than editing and applies to the whole set.

• Get out from under the overhead light. A downlight directly above is the single biggest cause of a hot forehead. Move a metre sideways towards a window and the bright band goes with it.
• Turn so the light skims. A source at 45 degrees produces far less specular return towards the camera than one square on.
• Make the source bigger. Sheer curtain over a window, bounce a lamp off a pale ceiling, or step into open shade outdoors. Bigger source, broader and gentler highlight.
• Blot, do not wipe. Press a tissue or blotting paper on and lift it off. Wiping spreads oil and pulls off any powder underneath.
• Wait five minutes. Coming in from heat, a crowded room or a walk uphill, skin produces noticeably more shine for a few minutes. Take the photo after the drink, not before it.
• Keep direct flash beyond a metre. A flash close to the face is a small, very hard source and it produces the worst version of this on every frame. See the flash photography notes for the distances that work.