Kenko has announced the second version of its 400mm f/8 telephoto mirror lens. The new version features optical tweaks to improve image quality, compared to the previous model (which came out in July ...

We may earn revenue from the products available on this page and participate in affiliate programs. Learn more › Believe it. Adoram’s ProOptic 500mm f/6.3 ($160, direct; adorama.com) shares all the ...

This is technically known as a catadioptric lens and has an unusual construction of mirrors and lens elements. As well as glass elements there are mirrors at the front and rear to fold the light as it ...

The technical definition of a telephoto lens is one with a focal length greater (or longer) than 50mm (on the 35mm/full frame forma), but the telephoto range is more generally accepted to begin at ...

The Kase Reflex 150mm f/5.6 AF is getting a lot of hype online –but does nobody remember how bad these lenses are?

LEWISVILLE, Texas, July 16, 2025 /PRNewswire/ -- Ophthalmic lens technology leader HOYA Vision Care announced today the launch of HOYA Polarized Lenses with Lumacore™ Mirrors. The patented technology ...

For hundreds of years, the principle behind the telescope has been as simple as it gets: build a lens or mirror to collect a large amount of light, focus that light onto a detector (like an eye, a ...

[Robb] has had a little experience making lenses from scratch. His first attempt was for a DIY projector, and while the lens was a little blurry, it did work rather well for something carved out of a ...