Thursday, August 08, 2019

Equation provides solution to lens imperfections

gizmodo reports: [edited]

It’s a problem that plagues even the priciest of lenses, manufactured to the most exacting specifications: the centre of the frame might be razor-sharp, but the corners and edges always look a little soft.

On paper, a curved glass lens should be able to redirect all the rays of light passing through it onto a single target known as its focal point. But in the real world, it just doesn’t work that way. Differences in refraction across the lens, as well as imperfections in its shape and materials, all contribute to some of those light rays, especially those entering the lens near its outer edges, missing the target. It’s a phenomenon known as spherical aberration, and it’s a problem that even Issac Newton and Greek mathematician Diocles couldn’t crack.

But that’s all going to change thanks to Rafael G. González-Acuña, a doctoral student at Mexico’s Tecnológico de Monterrey. After months of work, he came up with an equation that provides an analytical solution for counteracting spherical aberration, which had been previously formulated back in 1949 as the Wasserman-Wolf problem.

For lens makers, it can provide an exact blueprint for designing a lens that completely eliminates any spherical aberration. It doesn’t matter the size of the lens, the material it’s made from, or what it will be used for, this equation will spit out the exact numbers needed to design it to be optically perfect.

It promises to help improve scientific imaging as well in devices like telescopes and microscopes. But even the average consumer will benefit from González-Acuña’s work. It will allow companies to manufacture simpler lenses with fewer elements which cost considerably less while offering improved image quality in everything from smartphones to professional cameras.

Thanks to Brook for the link.

Image courtesy of  unsplash-logoDustin Lee

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