Why do we need masks in Photoshop and how to use them | Articles | Photo, video, optics

Need to rearrange the mod­el to a dif­fer­ent back­ground? Change the col­or of the sky, eyes, hair, skin? Do you want to sharp­en only on the hero’s face, but not touch the envi­ron­ment?

As soon as you need to cor­rect part of the image, and not the whole thing, masks come into play. We tell in detail what masks are, how to use them and how to set up tools for work­ing with them.

Pho­to: Eliz­a­beth Chechevic / instagram.com/chechevic_a

What is a mask and what can be done with them

A mask is essen­tial­ly a sten­cil that is applied to a lay­er, mak­ing parts of it invis­i­ble. At the same time, you your­self, man­u­al­ly, choose what will be vis­i­ble and what is hid­den.

With masks, you can:

• Cut out an object or back­ground

With the help of a mask, you can cut out any ele­ment of the pho­to, and “hide” every­thing else or, in pro­fes­sion­al slang, mask it.

For exam­ple, you put a mask on a por­trait pho­to and hide the back­ground (more on how to work with the mask in the next sec­tion). Then you, as a view­er, will only see the mod­el on a trans­par­ent back­ground.

The back­ground of the pho­to is replaced with a mask / Illus­tra­tion by the author

Why is it bet­ter to cut with a mask? Why, if there is an eras­er? The mask does not remove pix­els, but only “hides” them. At any time, you can redo the result, mod­i­fy it.

The sim­plest anal­o­gy is the invis­i­bil­i­ty cloak that Har­ry Pot­ter had. Being under it, a per­son did not dis­in­te­grate into atoms, he only became invis­i­ble to oth­ers. The mask also works.

• Selec­tive­ly change col­or, con­trast, sat­u­ra­tion, tint, sharp­ness

Let’s say you want to change the mod­el’s eye col­or from green to blue. If you add a lay­er that changes col­or, then you will achieve your goal, but, except for the eyes, the skin, hair, back­ground and all objects in the pic­ture will also become blue. With the help of a mask, you can show the effect only where you need it. In this case, on the iris­es.

Using a mask, you can only affect part of the image. For exam­ple, sharp­en only the face, or increase the con­trast only on the mod­el, or make only the back­ground less sat­u­rat­ed so that it is less con­spic­u­ous, and the empha­sis is on the hero. Or all togeth­er — the mask can be applied to each lay­er, and the num­ber of lay­ers is not lim­it­ed.

In the pho­to, using masks, the sharp­ness is raised only on the mod­el and the upper part of the back­ground and only the envi­ron­ment is dark­ened with­out affect­ing the hero­ine / Illus­tra­tion by the author

Effects that can be done with a mask and adjustment layers

A short algo­rithm for any of the effects (more on how to use masks and edit them, where to find adjust­ment lay­ers — in the sec­tions below):

• Add an adjust­ment lay­er, cre­at­ed auto­mat­i­cal­ly with masks (Lay­er — New Adjust­ment Lay­er);
• We pass to the mask;
• We erase the effect from those parts of the pic­ture where it is not need­ed.

— Add Curveto increase con­trast, tone, light­en, or dark­en the sub­ject in the frame. About what curves are capa­ble of and what you can do with them, read the text.
— Change col­or with adjust­ment lay­ers Hue/Saturation (Hue/Saturation) or Selec­tive col­or cor­rec­tion (Selec­tive Col­or).
— To get the effect in the style of the noir action movie “Sin City”, when the entire pho­to is black and white, but only one detail is col­ored, add an adjust­ment lay­er Black & White.
— Make the object rich­er with adjust­ment lay­ers Juici­ness (Vibrance)or Hue / Sat­u­ra­tion (Hue / Sat­u­ra­tion).
— Shade the back­ground or object with Col­or bal­ance (Col­or Bal­ance), Pho­to Fil­ter or Col­or search (Col­or Lookup).

How to use masks

How to add a mask

A mask can be added to any lay­er. Enough in the palette Lay­ers (if you do not have it, call it with the F7 key, or find it in the menu Win­dow / Win­dow) click on the rec­tan­gle with a cir­cle in the cen­ter, and it will attach to the lay­er you are on.

This is what the mask icon looks like in the lay­ers pan­el / Illus­tra­tion by the author

There are lay­ers that are cre­at­ed imme­di­ate­ly with masks. These are adjust­ment lay­ers, which can be found in the palette. Lay­ersif you click on the black and white cir­cle, or in the palette Cor­rec­tion / Adjust­ments (if not, you can find it in the menu Win­dow /window). For them, it is point­less to cre­ate anoth­er mask — it auto­mat­i­cal­ly comes with the kit.

Lay­ers from select­ed menus are cre­at­ed imme­di­ate­ly with masks / Illus­tra­tion by the author

How to work with a mask

• To start work­ing with a mask, be sure to click on it by click­ing on the cor­re­spond­ing square with the mouse. So you show the pro­gram where you are cur­rent­ly work­ing.

• Work with a mask hap­pens one tool. The most com­mon brush, which can be found on the left of the tool­bar, or called with the hot key B (short for Brush).

• When you switch to the mask and select a brush, the col­ors in the palette on the left will auto­mat­i­cal­ly switch to black and white (if not, click on the black and white box above the palette).

On the left is a palette with black and white, which are used with masks. To start inter­act­ing with the mask, be sure to click on the square with it, as shown in the cir­cle on the right / Illus­tra­tion by the author

• The most impor­tant thing to remem­ber when work­ing with a mask is that the black col­or “eras­es”, hides pix­els or cor­rec­tion (if it’s hard to remem­ber, you can build an asso­cia­tive series: black = dark­ness, and noth­ing is vis­i­ble in the dark), and white col­or shows a cor­rec­tion, leaves its vis­i­ble (same anal­o­gy: white = bright sun­ny day, every­thing can be seen per­fect­ly dur­ing the day).

If you want to speed up your work in Pho­to­shop, you need a graph­ics tablet. Any, the most bud­get option of the small­est size will do. For exam­ple, Wacom Intu­os S. Even with it, you will work many times faster, and your hand will not hurt from the mouse. The main thing is that the tablet pen should be light. By the way, we have put togeth­er a guide on how to choose a graph­ics tablet.

How to edit a mask

When work­ing with a mask, you sim­ply paint over it with a brush, switch­ing between black and white (you can quick­ly do this using the hotkey X). To make the mask neat, use the fol­low­ing tricks: adjust the brush, change the opac­i­ty of the mask, and refine it in the Prop­er­ties palette.

How to adjust the brush when working with a mask

After select­ing a brush, a line will appear at the top of the pro­gram, allow­ing you to change the para­me­ters of the tool. Three of them are impor­tant:

If you remove the back­ground, set the size to a larg­er one so that the work goes faster. If you cut out an object, draw details, for exam­ple, by chang­ing the col­or, it is bet­ter to work with small brush­es and at a large approx­i­ma­tion.

You can quick­ly enlarge or reduce brush­es using hotkeys [ (буква Х в русской раскладке) или ] (hard sign).

• Brush hard­ness

If the brush is too soft, then you will inevitably touch unnec­es­sary details in the pho­to. But work­ing with 100% brush hard­ness can also give slop­py results — the out­line will be too sharp and rough.

There are no exact rec­om­men­da­tions, you have to sort it out man­u­al­ly. But, if you change the col­or, raise the con­trast, sharp­en, then the hard­ness of the brush is usu­al­ly soft­er. If you cut out an object — hard­er. At the same time, start from how sharp the object or mod­el being cut out is — the sharp­er the con­tour, the high­er the stiff­ness of the brush.

The main para­me­ters we pay atten­tion to when set­ting up a mask brush, even when work­ing with a graph­ics tablet / Illus­tra­tion by the author

The same brush size looks com­plete­ly dif­fer­ent depend­ing on the hard­ness. You can change the hard­ness by click­ing on the drop-down box at the top or by press­ing the left mouse but­ton while work­ing.

• Brush Opac­i­ty

Allows you to make the impact more grad­ual. Rel­e­vant if you work with adjust­ment lay­ers (change col­or, con­trast, bright­ness, etc.). If you are cut­ting, then set the para­me­ter to 100% to work faster.

The Properties palette when working with a mask

You can also refine the mask and make it more accu­rate in the palette Prop­er­ties (find it in the menu) Win­dow / Win­dowif it is not in your work­space):

• Den­si­ty. Makes the black areas of the mask vis­i­ble. In fact, this is the opac­i­ty of the black ele­ments of the mask.
• Feath­er­ing. Makes the out­line of the mask more blur­ry. It can help if you worked with a too hard brush.
• The Refine menu con­sists of three options:

• Selec­tion and mask / Select and Mask. Opens a sep­a­rate win­dow where you can refine the out­line, make it hard­er, smoother, select fleecy ele­ments of the pic­ture (hair, fur) using the Refine Edges brush or the Edge Detec­tion but­ton.
• Col­or Range / Col­or Range. Allows you to add or remove pix­els from the mask based on their col­or. For exam­ple, you can select the skin in a cou­ple of clicks to change its col­or.
• Invert / Invert. Swaps the black and white col­ors on the mask in places. You can also do this with the Ctrl + I keys.

To acti­vate the Prop­er­ties palette and access the mask set­tings, click on the mask square (low­er cir­cle on the left). The Col­or Range func­tion (win­dow on the left) made it pos­si­ble to select back­ground ele­ments and quick­ly change their col­or using a curve / Illus­tra­tion by the author

conclusions

• The mask hides part of the image or adjust­ment lay­er, mak­ing it tem­porar­i­ly invis­i­ble. This allows you to change and mod­i­fy the result at any time.
• Work with the mask is done with a reg­u­lar black or white brush.
• Black hides the cor­rec­tion, white shows it.
• Refine the mask, not only by hand. This requires the Prop­er­ties palette. There you can change the opac­i­ty, feath­er the edges and refine the out­line of the mask if you click the Select and Mask but­ton.
• If you need to quick­ly select pix­els of a cer­tain col­or in order to cor­rect them lat­er by chang­ing their tone, sat­u­ra­tion, in the Prop­er­ties palette, press the Col­or range but­ton. This way you can quick­ly change the col­or of the sky, refine the col­or of the skin, etc.