Publish-processing could make or break a picture. It doesn’t matter how a lot you modify in your picture editor of selection, even a small adjustment can harm your picture if it isn’t utilized accurately.
A standard mistake I see with post-processing is making use of all changes globally (i.e. to all the picture). It’s one thing we not often need, which is why we have a tendency to make use of Lightroom’s Highlights and Shadows sliders to regulate the publicity fairly than the Publicity slider. And when you convey your picture into Photoshop you possibly can apply extra superior strategies and changes.
Greater than ever, it is advisable to know the best way to make these changes accurately.
And that’s the place luminosity masks come into the image.
What are Luminosity Masks?
When you’ve learn any of my earlier articles you could have seen me discuss selective post-processing – making changes that solely have an effect on particular areas fairly than all the picture.
Luminosity masks are choices based mostly on a pixel’s luminosity worth. This implies you possibly can precisely choose solely the brilliant, darkish or midtone pixels. We are able to refine these choices to have an effect on solely the brightest brights or the darkest darks, and use them as layer masks for our changes.
Since they’re based mostly on the pixel’s brightness, we are able to get extraordinarily correct choices that concentrate on solely the precise pixels we wish. Having an correct choice means we keep away from sure undesirable artifacts you may in any other case expertise.
You received’t discover luminosity masks in a listing or menu inside Photoshop (though third-party plugins can automate the method). As an alternative, it is advisable to create them manually by making choices based mostly on the RGB channels.
The way to Use Luminosity Masks
Now that you recognize what they’re, the following factor it is advisable to know is the best way to use them. As you in all probability know they don’t regulate the picture themselves. As an alternative they’re a variety you possibly can apply to any layer or group you need to use a layer masks on.
Earlier than we have a look at the best way to use them, we have to have a look at the best way to create them. You are able to do this both manually or by utilizing a third-party plugin. I strongly advocate you learn to create them manually earlier than you begin utilizing a plugin to hurry up your workflow.
The way to Make Luminosity Masks
Let’s create a Brights mask, which can choose the brilliant areas of the picture however go away the midtones and darks untouched. Take into accout that is the broadest brights masks, and also you’ll in all probability must refine it to focus on extra particular pixels. (Extra on that one other time.)
Begin by opening a picture in Adobe Photoshop, and observe these steps to create the masks:
- Maintain down Ctrl/Cmd and click on the RGB thumbnail within the Channels Tab. You must now see marching ants round a number of areas of your picture.
- Save the choice by clicking the Save choice as channel icon. The choice is saved as a channel and given the title Alpha 1.
- Double-click the title of your new channel ‘Alpha 1’ and rename it to ‘Brights 1’.
- Maintain down Ctrl/Cmd and press D to deselect the choice.
Not too arduous, proper?
We’ll make the Darks masks subsequent. It’s just about the identical course of as making the Brights masks besides we have to invert the choice:
- Maintain down Ctrl/Cmd and click on the RGB thumbnail within the Channel Tab.
- Maintain down Ctrl/Cmd and Shift, and press I to invert the choice.
- Save the choice.
- Double-click the brand new channel’s title and rename it to ‘Darks 1’.
- Maintain down Ctrl/Cmd and press D to deselect the choice.
Lastly, we’ll create the Midtones masks. This one is made barely otherwise to the primary two masks.
- Choose all the picture (maintain down Ctrl/Cmd and press A).
- Subtract Brights 1 (maintain down Ctrl/Cmd and choice/alt, and click on on the ‘Brights 1’ channel’s thumbnail).
- Subtract Darks 1 (maintain down Ctrl/Cmd and choice/alt, and click on on the ‘Darks 1’ channel’s thumbnail).
- Save the choice and rename the brand new channel to ‘Midtones 1’.
We’ve now created the three fundamental luminosity masks. The method might sound complicated at first, however quickly you’ll discover creating masks as simple as one, two, three.
The way to Apply and Use a Luminosity Masks
Now that we now have our masks, let’s have a look at the best way to use them. As I discussed earlier, you possibly can apply luminosity masks to any layer or group you need to use a layer masks on. This consists of merged layers, adjustment layers, teams, sensible objects and extra.
A typical processing state of affairs is the foreground being is a bit too darkish whereas the sky is completely uncovered.We are able to repair this by growing the publicity utilizing a Curves Adjustment. However utilizing a Curves Adjustment with out a masks will brighten not solely the shadows,but additionally the areas which are already effectively uncovered.
So let’s use the Darks masks.
Maintain down Ctrl/Cmd and click on on the Darks channel’s thumbnail to activate the choice. (You’ll understand it’s lively once you see the marching ants.)
With the choice lively, create a Curves adjustment layer. Because the choice is lively, the Darks luminosity masks shall be utilized to the Curves’ layer masks. Any changes you make on this explicit layer will solely have an effect on the areas represented by white on the masks.
Now merely pull the Curve as much as brighten the darks. You’ll be able to toggle the masks on and off by shift-clicking the layer masks to see the adjustment with and with out the masks. (It makes an enormous distinction.)
This is only one manner you need to use luminosity masks. When processing a picture I exploit them a number of occasions with a wide range of changes. They will even be used to mix a number of photographs.
And whereas third-party plugins can automate the method for you, you actually ought to learn to create them manually first. Understanding how they work makes it simpler to know the way and when to make use of them – and when to not.
When you’re on this topic, check out my eBook A Photographer’s Information to Luminosity Masks the place I educate you the whole lot it is advisable to learn about them, in addition to a wide range of different masks and superior choices.