Photo & Video > Photoshop > Capturing And Processing Night Photography > Cityscape Image: Selections And Mask Theory

Cityscape Image: Selections And Mask Theory


Capturing and Processing Night Photography


Lesson Info

Cityscape Image: Selections And Mask Theory

Now, what I wanna do is I want to create selections to mask out one area and keep another area. Now, there is a zillion different ways you can make selections within Photoshop. My favorite probably is something called select color range. And select color range is pretty fascinating. The way that it works is, you wanna start by clicking on the layer and highlighting the layer that you want to select on. So, if I'm on this layer, and I choose select, color range, I'm going to get this box that's actually making a selection from this upper layer. It's ignoring this bottom layer at this point. That's an important fact to remember. And now, it says sampled color, so what I can do is, when sample color is highlighted here, I can take my mouse out, and maybe I just wanna select the orange at the bridge. If I click on the orange at the bridge, it's only selecting that. And the white here shows the selected area. Now, ultimately what I wanna do, and I'm just gonna cancel out of here for just a ...

second and go back, ultimately what I wanna do is mask off the area of the image that I don't want. So for example, I could take my lasso tool, this is also a selection tool, and just, just to review, the very nature of a selection is that, when something is selected, whatever you do next is going to happen to that area. So if this area is selected, and I go image, adjustments, hue and saturation, that hue or saturation change is only gonna happen within the selected area. Okay, so I'm gonna cancel out of that. This is a very rudimentary selection. The selection I wanna make is a little bit more complex. So I'm not gonna use my lasso tool, I'm not gonna use my rectangular marquee, or elliptical tool, these are all selection tools. What instead I'm gonna use is my select by color range. So my goal is basically to select these highlighted areas right in here and darken them down. All right? And by darkening them down, what I'm gonna do is punch through this layer. So let's put this dark one on top. I want these to show through, but I want the rest of this image to look like this. Now, the way that I like to imagine this is that, if you have a print laying on a table, and you take another print, photographic print, and lay it on top, you cannot see what is below. You can't see this layer. So basically, what we're doing with selections and masks, is very carefully cutting away this upper layer. So now, imagine I have these two layers, and this one is cut. We lay it on top. You're gonna be able to see the bottom layer, because you can see through this. So the top layer always obscures the bottom layer, unless there's bits missing out of that layer. And that's what our selections and masks are gonna do. So let's start really rudimentary here, and let's just do a lasso tool, and I do that. Now, remember, whenever you have a selection active, which we do, because this has got marching ants, whatever we do next is only going to occur within the selected area. All right. So you saw how I changed the hue in only a selected area. But, if you have a selection active and you go down to this little front-loading washing machine down here, it's called the add a mask button, by the way, if you leave your mouse there for a couple of seconds, it'll pop out and tell you what it is. It's going to turn that selection into a mask on that layer. And there you go. So what's happening here is, the white of this layer, which was our selection, allows us to see through this part of the image. It's allowing us to see it. It's almost as if all this black is being cut away by a pair of scissors, and what it's able to see now is the image beneath. So that's like, here's my top layer, and see, there's my top layer, I cut this apart, all you can see is below it. So, just imagine it like a pair of scissors, and maybe that'll help you imagine what you wanna do. So let me go back in time. I'm hitting Command + Alt + Z to step back in time here. If I select the whole sky, if I select the whole sky here, and add a mask, it's allowing me to see this upper portion of the sky, but it's looking through to the bottom part behind it. Do you see that? This eye button here allows you to disable or enable that layer. All right. So I'm gonna throw my mask out by grabbing on the mask itself and dragging it to the trash. Not the system trash, but the trash in there. And here we wanna say, delete. All right. So those are some basic selections, but that's not what we wanna do. We want very, very accurate selections. The more accurate selections are your magic wand, which is underneath your quick select tool, your quick select tool, and select by color range. Those are the three very important ways to create a selection that's accurate and very detailed and complex.

Class Description

Creating night images poses unique challenges, particularly for those who are more accustomed to daytime photography. From focusing in the dark to calculating long exposures, night photography requires the photographer to build new skills and polish off some old ones. But there’s more to night photography than just capturing the image in the field. Like with other photographic disciplines, post-processing often plays a vital role in crafting the final image. Join photographer, author and National Parks at Night instructor Tim Cooper as he shares what you’ll need to know while you’re in the field, including lens choice, camera settings and exposure, as well as how to use Photoshop® and Lightroom® to create a night image that dazzles.