Here's Why Testing Cinema Lenses Didn't Matter Before, But Does Now

There are a handful of companies that are well-known for testing lenses. And the photographic community has a love-hate relationship with many of those that claim to have scientific tests, etc. Does it even matter? Can you tell the difference? Isn't it all just good enough? Regardless of your personal opinion, LensRentals has a respectable reputation for testing photographic lenses for optical features that we actually care about. They haven't tested many cinema lenses, but that's about to change — and for good reason.

LensRentals took to a recent blog post to discuss the history of their lens tests and how they've developed better methods and technologies for metrology (lens testing). It was only when digital cameras began exceeding the resolution of film cameras that manufacturers' in-house tests began to start showing their weaknesses. LensRentals claims they pushed back to some degree, but many manufacturers have come around and even visited LensRentals to learn from their metrology practices.

Since high-definition video, however, is shot at a resolution of two megapixels, various metrics of how good a lens really is simply didn't matter. Even 4K's eight-megapixel images have trouble resolving detail enough to expose weaknesses in lenses. However, as 6K, 8K, and beyond become more prevalent, LensRentals bets that they'll be seeing the same pushback from manufacturers claiming their lenses are too sharp to notice and are tested to rigorous standards even if the gear rental company scientifically proves them wrong. But there will be weaknesses in cinema lens design, and LensRentals is about to expose them.

The entire blog post is worth a read if you're interested in image quality, lens technology, and metrology that shows differences you might actually care about.

Do you shoot 8K? Can you see differences in some of the high-end lenses you're using?

Lead image courtesy of Maraj Chhaya, Flickr.

Log in or register to post comments


filmkennedy's picture

I shoot 8k on my Helium Weapon-and quite frankly I don't believe in lenses which are optimized for "4K". And I've seen so many resolution tests of lenses, and have done my own fair share of lens tests for various projects. But even vintage glass like Cooke Pancro's, Leica R's, Canon K35, Zeiss Super Speeds, Bausch and Lomb Super Baltars still hold up in resolutions above 4K.
I recently shot a short in 8k on my Leica Rs and saw it projected in 4K on a 40' screen and still they look amazing! Sure I don't shoot wide open, I'm aware of the limitations of my lenses-guess those pixel peepers have to complain about something.

So those lens manufacturers claiming that their lenses are rated for 4K are just trying to make you buy into their products while the vintage lenses still hold up to this day. If anything the imperfections of older glass help breathe some life in the electronic perfection today's 4K+ sensors! I'd much rather use old lenses with imperfections, massive flares, and a natural softness to help emphasize the story I'm trying to tell then what's considered to be 4K rated lenses today.

Pieter Batenburg's picture

One thing photographic lenses should copy is the T-stop value next to the F-stop value.