• Welcome to the Lightroom Queen Forums! We're a friendly bunch, so please feel free to register and join in the conversation. If you're not familiar with forums, you'll find step by step instructions on how to post your first thread under Help at the bottom of the page. You're also welcome to download our free Lightroom Quick Start eBooks and explore our other FAQ resources.
  • Stop struggling with Lightroom! There's no need to spend hours hunting for the answers to your Lightroom Classic questions. All the information you need is in Adobe Lightroom Classic - The Missing FAQ!

    To help you get started, there's a series of easy tutorials to guide you through a simple workflow. As you grow in confidence, the book switches to a conversational FAQ format, so you can quickly find answers to advanced questions. And better still, the eBooks are updated for every release, so it's always up to date.
  • 16 April 2026 It's Lightroom update time again. There are some new features, as well as bug fixes, new cameras and lenses. Also updated for 9.3.1.
    See What’s New in Lightroom Classic 15.3, Mobile & Desktop (April 2026)? for more details.

Develop module Mask Intersect Question (I Think)

Status
Not open for further replies.
kitjv

kitjv

Active Member
Joined
May 3, 2012
Messages
450
Location
Oregon, U.S.A.
Lightroom Experience
Intermediate
Lightroom Version
Lightroom Version Number
14.3
Operating System
  1. macOS 15 Sequoia
I need a bit of guidance on this. Suppose that I have a photo of a landscape surrounding a body of water. How do I create a mask that omits the water? I hope that I am not missing something obvious here. Thank you so much.
 
Sort by date Sort by votes
You better post the photo, because this depends very much on what that water looks like. Is it blue? Are there lots of reflections (of different color)? Also explain exactly what you are looking for. Anything but the water? Just the landscape (so no water but also no sky)?
 
Upvote 0 Downvote
I agree with Johan "A picture is worth a thousand words"
I have been dealing with a similar problem.. I have sky and mountains in a hazy rainy day.. I can't select the sky without selecting some of the mountains. I solved this by Selecting the sky as Mask 1. And for mask 2 I selected the sky again and inverted it. Through a series of Object Additions or Object subtractions to Mask 2. I was able to isolate the mountain that was the problem in Mask 1. I was them able to apply the develop corrections to that mask
 
Upvote 0 Downvote
Johan Elzenga said:
You better post the photo, because this depends very much on what that water looks like. Is it blue? Are there lots of reflections (of different color)? Also explain exactly what you are looking for. Anything but the water? Just the landscape (so no water but also no sky)?
Click to expand...
Sorry, Johan, for being so nebulous. But it was actually a hypothetical question. No specific photo in mind. In the past I have come across a landscape with a particularly bright element in it, such as a body of water. Clee's idea of using Object Addition/Subtraction might work. Also, it occurred to me that I might use Luminance Range Subtraction. I'll sort this out. Nevertheless, thank you for the responses.
 
Upvote 0 Downvote
OK, if it is just a hypothetical question: intersect selects what both masks have in common, so that is probably not what you would use here. What you would use is a simple subtraction. You create the landscape mask, and then subtract the water from it. How you select the water would depend on how it looks. If it is nice blue water, then most likely you can select it via color range. If it contains lots of reflections with different colors, then you might have to use a brush. If it is very bright, then luminance range may work.
 
Upvote 0 Downvote
Thank you, Johan. You confirmed what I was thinking. However, I did not know that Intersect selected what both masks have in common. Good to know.
 
Upvote 0 Downvote
kitjv said:
Thank you, Johan. You confirmed what I was thinking. However, I did not know that Intersect selected what both masks have in common. Good to know.
Click to expand...
Remembering Vend Diagram Unions
1744896784750.png
 
Upvote 0 Downvote
Actually, it's an intersection, not a union. :)
 
Upvote 0 Downvote
Johan Elzenga said:
Yes. Only the AuB part of this image is the intersection.
Click to expand...

It did not occur to me that i needed to explain Venn diagrams. Of course AuB is the union of both circles and the intersect of A & B is the part that applies to a mask intersection.


Sent from my iPad using Tapatalk
 
Upvote 0 Downvote
Status
Not open for further replies.
Back
Top