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Comment by boxey | Hacker News Reader

... with 2x Bowens DX1000 1kW flash lamps with dish reflectors to illuminate the bystanders at a distance of 1 meter.

That's ridiculous. Why is this even published?

The point is that the information is clearly there, and with current technology it is possible to extract it under ideal circumstances. It's not to say it's feasible or will be, but it's not hard to imagine sensors becoming advanced enough to capture the required light without using a special lens and artificially illuminate the bystanders.

Wrong, current image sensors have around ~50% quantum efficiency nowadays. [1] That's 1 f-stop from the theoretical maximum, while they're pushing around 10 f-stops above the top-of-the-line mobile phone cam / security cam.

The pace of technology is still limited by physics - if they take out the 2kW monster flash then the lens size needs to be increased to a diameter of several meters, just to maintain the same performance at a distance of 1 meter (!).

[1] https://en.wikipedia.org/wiki/Quantum_efficiency

You're missing the point. This is not a paper on image acquisition, it is a paper on image processing. Because they began from scratch, they used very favorable image conditions. They are not pushing the idea that their capture format is representative of an application.

We have no idea how hard it would be to recover an image using 50-5% of the light. No one has written that paper. Same for resolution. The paper does not claim to address that question so it seems silly to critique it for not doing so.

You can just absorb more light from a larger area then. We have microscopes that can see individual cells and telescopes that can see distant galaxies. There is nothing impossible zooming in on someone's eye.

Because if it's possible in lab circumstances today, then it'll probably be possible in less restrictive circumstances in 10 years?

There are so many papers published based on very artificial circumstances on stuff that is later developed into usable things...

The resolution and light gathering requirements should be pretty easy to analyze on paper to answer the question "will this ever be usable in practice"? The fact that this isn't done could suggest that the answer really is no, so the authors omitted it.

I'm sceptic that it will ever be even close to usable assuming sensor tech wont improve much and we don't reach some breakthrough in optics, i.e. bending light without huge heavy chunks of glass.

This experiment with huge flash guns and short distances is essentially like identifying the moon in an eye reflection and dreaming of doing deep space imaging the same way. The physics just don't allow it.

"The resolution and light gathering requirements should be pretty easy to analyze on paper"

Then why don't you?

Because I meant it should be easy for the guys who wrote this article, not for me. If I did them no one would believe me (and they shouldn't!).

This is a proof-of-concept. Sure, the conditions are ideal, but this is the first time anyone has made this work at all. Of course they're not going to start with a $20 digicam and a dimly-lit room.

Because things that seem ridiculous have a tendency to become not ridiculous over time given the pace that technology advances.

Though everyone'll flame you about "the future", you're probably right.

If you read the PLOS One acceptance criteria:

http://www.plosone.org/static/publication

you'll notice that scientific merit doesn't show up in there. The official policy is that if the methods and analysis are sound, then it will be accepted regardless of how irrelevant the actual study is. This is well known in academia and has resulted in a generally negative opinion of the journal among publishing researchers.

edit: I'd also like to point out that this isn't the case for all PLOS publications.

Yeah, I touched a sensitive nerve. It seems "the future" is interpreted by some as "Moore's law applied to everything", with gross disregard to physics, no thermal or optical or energy limits etc.

Year 2000 has passed, and we're all still waiting for our flying cars.

The reason we don't have flying cars is economics, not physics.

Also, people tend to totally overestimate limits of possibility. We haven't explored a lot of things that are possible with our current level of technology (again, mostly because economics). Moreover, our image processing algorithms are very crude. We're nowhere near efficient use of information encoded in images (in a way a theoretical Bayesian superintelligence would). A lot of things thought impossible become possible when you start throwing more and more "compute" at it. You can't break the laws of physics, but those laws are quite lenient.

I'm sure it's highly relevant and interesting to spy or (counter-)surveillance-type agencies.

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