Researchers figure out how to eliminate purple fringing in photography

Shawn Knight

Posts: 15,646   +199
Staff member
Something to look forward to: Researchers have made a promising advancement that could eliminate a pesky problem that has plagued photographers for centuries. With any luck, they'll be able to tweak the metacorrector for improved performance and add them to smartphones in the not-too-distant future.

Camera systems like those found in cutting-edge smartphones and high-end DSLRs are far more advanced than examples from just a decade ago. The underlying technology behind lenses, however, hasn’t changed much since the mid-1700s which means we’re still dealing with some of the same shortcomings that plagued our forefathers.

Chief among them is chromatic aberration, an optical issue that happens when a lens is unable to focus all wavelengths of color into a single focal point. This often manifests itself as a purple haze or fringe around an object as seen around the branches in the bird photo above.

Special types of glass can minimize chromatic aberration, as can in-camera software and post-processing applications like Photoshop. Thanks to recent work from researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), those efforts may not be needed for much longer.

SEAS researchers have created what they’re calling a metacorrector, a single-layer nanostructure that corrects chromatic aberration across the visible spectrum. Alexander Zhu, a graduate student at SEAS and co-author of the study published in Nano Letters, said metacorrectors are fundamentally different from conventional methods of aberration correction. “This means we can go beyond the material limitations of lenses and have much better performances,” Zhu said.

The tech can also work in tandem with existing corrective measures to further improve performance.

The researchers plan to further fine-tune the efficiency of the metacorrector for use in miniature and high-end optical devices.

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While it is a real issue, to be frank, it is only distracting when brought to the attention of the viewer so the question is; is this a real issue or one manufactured in order to be sold as a "must have", not unlike deodorant, hair color and the many other "necessary" items that the American public has been sold on. Human's are the most gullible creatures on the earth .... not because we are stupid but because we are willing to believe things that simply are not as they appear ........
 
Meanwhile in game developer land:

"Dude, what do you think of this chromatic aberration filter I added to the game?"...
No kidding.... I HATE it when devs add lens flare and other crap to game visuals just because they think it looks cool. Most of the time, the avatar is a human; not a remotely controlled machine with cameras for eyes. Human eyes don't experience lens flare.
 
No kidding.... I HATE it when devs add lens flare and other crap to game visuals just because they think it looks cool. Most of the time, the avatar is a human; not a remotely controlled machine with cameras for eyes. Human eyes don't experience lens flare.

Ahem .... humans that wear glasses do ......
 
While this is a nice development for camera lenses, chromatic aberration is very annoying in magnified optics like in refracting telescopes. All that CA is magnified and smears your high power view.
Seeing as telescopes designed without CA cost 5 to 10x the cost with CA, if this ends up being cost effective, it would be a great help for lower cost ‘scopes. For instance a 100mm refracting scope with CA is about $100 while the same scope without CA is $1000. Even if this adds $200 to the cost of the CA scope, that’s still a lot less $$$.
 
No kidding.... I HATE it when devs add lens flare and other crap to game visuals just because they think it looks cool. Most of the time, the avatar is a human; not a remotely controlled machine with cameras for eyes. Human eyes don't experience lens flare.

Ahem .... humans that wear glasses do ......
I'm quite nearsighted and wear high-density glass lenses and the chromatic aberration is quite extreme. for an example, right now I look thru the edge of my lens at my monitor, left side is red then yellow banded, right side blue to purple banded, This is in lenses that cost about $400 CAD each. I'd love an improvement.
 
While it is a real issue, to be frank, it is only distracting when brought to the attention of the viewer so the question is; is this a real issue or one manufactured in order to be sold as a "must have", not unlike deodorant, hair color and the many other "necessary" items that the American public has been sold on. Human's are the most gullible creatures on the earth .... not because we are stupid but because we are willing to believe things that simply are not as they appear ........

Hmmm if you think 'deodorant' is an unnecessary item then you must not have much sense of smell! I know a few people who don't have a body odour, but for most of us, including me, it's an essential to be able to interact without crinkling people's noses!
 
Hmmm if you think 'deodorant' is an unnecessary item then you must not have much sense of smell! I know a few people who don't have a body odour, but for most of us, including me, it's an essential to be able to interact without crinkling people's noses!

Ask your grandparents about it .... they have all the in's' and outs on that one!
 
Ask your grandparents about it .... they have all the in's' and outs on that one!
Actually I did when they were alive! They used a crystal of some sort - you can still buy them for travel, and they are odourless, they also used some sort of paste that they made up and rubbed in their armpits before washing it off, but mostly they said everyone just got used to the smell!
 
but mostly they said everyone just got used to the smell!
Now everyone would rather risk cancer than be put in that position. With cancer so rampant no one can deny the possibility of long term chemical exposure from mixing daily cleaners/fragrants causing cancer.
 
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