Fake AI skies look amazing, but not everybody’s thrilled


sky replacement tool in Luminar 4
Pick a sky that wasn't there when you took the photo.
Photo: Skylum

Imaging software company Skylum markets its photo editing tools as huge time savers. Just click a preset look or move a few slider bars and you have a beautifully styled final image within minutes.

Skylum was on message when it announced an upcoming AI tool for instantly replacing the sky. The company declared, “The days of spending a lot of time manually creating a complicated mask to replace skies in an image are over.”

Yet the debate over artificial intelligence’s role in photography is only beginning. In the week since Skylum announced and demoed AI Sky Replacement, photographers have spent considerable time in online forums drawing lines between ethics and creativity.

The sky replacement filter from Skylum is one of many new tools expected with the Mac version of Luminar 4, due out this fall.

Sky in picture is not the limit

The tool analyzes an image, identifies where the sky begins and ends around elements in the foreground and then seamlessly replaces a dull sky with a more dramatic one. Editors can choose among different skies showing clouds with realistic and saturated light and colors.

screen shot showing how AI Sky Replacement works
The before and after.
Photo: Skylum

Photo editors can adjust the strength of the filter. Some results, as seen in the demonstration video below, look more realistic than others. The filter appears spot on with how it integrates a sky with small, complicated shapes and lines, like the ones created by a leafy tree.

Not long after photography’s beginnings, practitioners started manipulating the captured image, working in the darkroom to add or take away elements. Skies were “burned in” around subject matter to appear touched by “the hand of god.” Others had negatives of nice clouds on hand just to improve a picture’s appeal.

That tradition continued with digital imaging with some photographers, as Skylum’s marketing references, working for hours in post-production to change the sky and make the changes look as real as possible.

AI Sky Replacement and view of the ‘purist’

This may be why stories about AI Sky Replacement drew such a strong reaction. The artificial intelligence is frighteningly good.

On sites like PetaPixel and DPReview, a story about the sky replacement filter lit up the comments with mostly snark and criticism at the very thought of resorting to a “fake sky.” Why not simply prepare to be in place for good weather, good landscape and the right time of day?

“Deepfakes are becoming scarier by the day!” said SpeedyNeo on DPReview.

“Nothing worse than lying (to) yourself,” GinoSVK wrote on DPReview.

“What’s even the point of taking photos anymore? Jrbdog wrote on PetaPixel

“We could just generate random beautiful pictures at home,” Adrian Hill wrote on DPReivew “I could just stay at home in front of my screen! Amazing.”

Sone on DPReview discussed their workflow and freely shared how they shoot beautiful skies to have on hand to be used with future images not blessed with nice light or weather.

In defense, Parshua wrote, “(Maybe) you should wise up to the fact that not every photo taken is for documentary reasons, and a huge industry relies on graphic design.”

“I can only laugh at you purists,” wrote Edwaste. “If any of you bothered to look into the history of photography you would know that replacing overexposed skies dates as far back as the civil war.”

TORN liked the “really cool tech,” but warned not to overuse it. “My impression is that we already went beyond a natural look in the average viewer’s taste. (Many) people will judge an image as not spectacular enough. Sky replacement will be just another tool to do what is already popular – only with a more accessible solution.”


Daily round-ups or a weekly refresher, straight from Cult of Mac to your inbox.

  • The Weekender

    The week's best Apple news, reviews and how-tos from Cult of Mac, every Saturday morning. Our readers say: "Thank you guys for always posting cool stuff" -- Vaughn Nevins. "Very informative" -- Kenly Xavier.