top of page
  • Ed Dozier

Using ON1 Photo RAW 2023 for Sky Swapping

The ON1 Photo RAW 2023 editor is a full-function photo editor that uses artificial intelligence for many of its features, which includes smart masking, smart noise reduction, smart sharpening, and of course sky swapping.

This editor supports up to 14 layers and includes focus-stacking, multi-file HDR, panorama stitching, and plug-in support. Due to the many AI features, you’ll need a pretty modern computer with a good GPU in it, or else you will end up spending a lot of time waiting for tasks to complete.

In this article, I’ll focus on the “sky swapping” feature. The editor comes with many built-in skies, but it also lets you import your own sky photos and therefore extend its library of choices.

There are many photographers whose blood would boil at the mere thought of replacing the sky in a landscape with some ‘fake’ sky. If that’s you, then this feature is definitely not for you.

The Sky Swap feature utilizes AI to do its masking, which means that you can replace a sky in mere seconds when the masking works properly. As I quickly found out, however, it doesn’t always mask correctly. When this happens, there are many helpful adjustments and manual masking tools to clean up masking problems.

It’s tempting to get a little lazy and always pick a built-in sky image to use with your photos, but that would lead to many of your shots having an embarrassing amount of repeated skies. I’ll show you how easy it is to add your own shots into the sky library, so that you don’t fall into this trap.

Before you start swapping skies, I’d recommend that you go into the

Edit | Preferences… | System

and change the “Auto” default to whatever your system hardware really is. I ran this editor on a laptop (Intel HD Graphics 4600 GPU) using both the “Auto” setting and also specifically the Intel GPU setting. The AI features all failed miserably with these settings. When I specified the “CPU” option for the AI Processor, then all features worked normally, although at quite a slow pace.

Featureless sky replaced with dramatic clouds

AI did a great job at complex masking to swap this sky

The examples above show what artificial intelligence is capable of doing with complicated masking tasks. The black-and-white shot uses my own cloud image, while the color shot above uses one of the canned ON1 cloud images.

To add new sky images to the ON1 library, you begin by clicking Import in the Sky tab:

Add images for sky swapping

The image file types that are allowed for skies are basically the same files allowed by the ON1 editor for general image editing. File types include jpeg, png, tiff, camera ‘raw’ files, and Adobe DNG.

Import dialog

Click the ‘Import’ button, and then you can browse to where your sky images are that you want to add to the library.

Select the sky image(s) to add to the ON1 sky library

In the screen shot above, I’m selecting raw image files from a Nikon camera.

Place the selected images into an existing category or a new one

If your image files are acceptable, you’ll get a ‘success’ dialog

Select a custom category of sky shots

The custom category is now available with your skies

After clicking the “Sky” tab, the editor will start an AI masking operation of your photo being edited.

Click the little ‘mask’ icon to get masking options

You get a little icon showing the masking results, shown in black-and-white. If you click this little icon, you get several masking options displayed. You can then click the “View” button to see the mask overlaid on your image being edited, to see how good of a job the AI masker did. If the mask is fine, then you can just re-click the “View” button, and the mask overlay will disappear.

Sub-standard masking job

Clicking the “View” button gets the AI-generated sky mask to display. As shown above, it didn’t do a particularly good job. The masking tools just below the “View” button can help clean up the mask, though. The red color here is where a replacement sky won’t get placed.

Manual mask fixes

As shown above, the “Levels” control has 3 sliders on it. By moving those sliders (the little circles) to the left, the horizon line mask gets considerably better.

Using the masking brush (left side of editor) the little spots still left can be erased. Make sure that the masking brush shows a little “-“ in it. If it shows a “+” instead, then click “Shift-X” to toggle the mode from “paint in” to “paint out” (erase). To change the size of the masking brush, use the bracket keys [ ].

If you aren’t using a custom category, then just click the “Category” underneath “Sky:” and then click the “v” underneath the category to select the exact sky you want to use. As you scroll over the different skies, you’ll see it overlaid on your photograph and replacing your original sky.

Additional fixes

As shown above, I adjusted the new (custom) sky’s brightness, I lowered the foreground brightness (to look more like it’s in shade), and I clicked the “Reflection” button, since this shot also has a body of water in it.

The clouds shown above were tone-mapped a bit using HDR Efex Pro 2, prior to importing the shot into the sky library. With this sky replacement feature, I can now separately control the look of the sky and the look of the ground.

Final shot

In the final photo, you can see that I changed it from being originally a sunny day into a cloudy day. I doubt that anyone would ever know that the sky was totally altered.


I purchased the ON1 Photo RAW 2023 editor for its sky replacement feature. I could have purchased the ON1 Skyswap AI program for even less money, but then I wouldn’t have gotten the full-featured editor.

I really enjoy the ability to get much more dramatic skies than I normally encounter. Now, I take the opportunity to shoot only skies sometimes, in order to expand the size of my custom sky library. Having more options for getting better skies than what I often encounter while out shooting landscapes is great.

Like pretty much everything else, the ON1 Photo RAW 2023 isn’t perfect. With a little extra work, though, it can produce some really amazing photographs.

Originally a cloudless day



Recent Posts
bottom of page