The answer was the worlds fastest super computer at the time. I was a bit shocked that he claimed that was the state of the art for lens manufacture in industry too - no idea how true that was. But figured that if you needed that much computation it made sense.

Well I have 2x that under my desk now and I use it to do local development before I push to cloud machines with 100x the power where the actual work happens.

It's possible due to things like:

- Much better lens coatings (allowing for more elements without flare)

- Computer modelling

- Being able to better machine aspherical elements

On integrated cameras, like an RX100, we can do even better due to digital. We don't need low-distortion, but just well-characterized distortion which a computer can invert.

Those old lenses -- at least the ones still working -- do have build quality. Adjust their prices at the time for inflation, and have a look at modern Zeiss, Leica, and other premium lenses. You'll see similar build quality.

For fun, next time you're looking at old lenses, pick up a Quantaray too, for fun. Or most older (before around 2000) Sigma lenses. Or other off-brands. You'll see unparalleled build quality, but in the other direction -- eighties-era plastic. The optical quality is bad. Not "fun" bad, "vintage" bad, or "whimsical" bad, but just bad.

When we look at older stuff, we tend to look at stuff which stuck around, but even that Quantaray is high-end compared to an older consumer camera. Most people who owned a camera had a non-SLR one. You looked through a little window on top, and the pictures were shot through the main lens. Those were even worse. Or a disposable (a single plastic element lens).

f/2.7, sharp at fully open, parfocal, zero focus breathing, fully manual zoom lenses...

and what used to be...

f/5.6, sharp only when stopped down even further, massive focus breathing, prime lenses...

well, vintage lenses start to look like toys.

Roughly the same optical design, limited to f/2.8, will be better in all respects.

A good way to think about this -- oversimplified obviously -- is you have a bunch of functions you're trying to cancel with e.g. a linear combination. If you look really close to the center, it's already a flat line. If you step out a little, two are adequate (have the slopes cancel). As you go further and further out, things become increasingly wonky. That's why you have super-complex designs for an f/1.8 zoom -- to get that cancellation right -- but even a single element works fine at f/22.

There actually were f/1.8 zooms all along, but for applications which didn't demand that sharpness (TV and CCTV). You can pick those up cheap and see what happens. They're sometimes fun on a real camera too (many will span a μ4/3 sensor with just a tad of vignetting).

Particularly since the old lens was designed for film, perhaps even black and white film. The choice of film has a much larger impact on color rendition than the lens would have. Also, unlike sharpness, color rendition is highly subjective and easily corrected. If you're shooting to JPG and you don't like how the camera is interpreting the colors from a lens, most cameras allow you to customize the white balance.

I'm primarily doing videography, but most of the vintage lenses I've tested are too soft to crop a 1080p vertical "short"-style video out of a 4K landscape video (even though the landscape video may look fine).

It's not just my old konica minolta lenses, though, the more affordable Sony lenses from 2015 are just as bad.

I'm now using contemporary fujinon cine lenses and they're tack sharp all the way to the edge, even fully open at T/2.8

That said: If you've got hidden gems, or like the less clinical look of vintage lenses, go ahead, have fun!