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Here are my notes, sources, and attributions - sorry it's so disorganized!https://www.gearpatrol.com/tech/a379199/what-is-a-curved-camera-sensor/
: a paper discussing a well-known property of light where the focal plane is curved coming through a optics, and thus the film should be curved as if around a sphere whose center is mid-way between the lens and its focus. But it’s a challenge to manufacture, store, and use the curved plates.
Through the film era and into the digital era, we never figured out how to make curved sensors. So film, digital sensors, always flat, but not because it was ideal, but because we didn’t have the technology… until now.
1971: Schmidt telescopes?? http://adsabs.harvard.edu/full/1975AASPB...8...20R
(a discussion of just how far you can bend the glass before it breaks - the curve helped but they wanted more).
2014: Sony unveils curved sensor tech https://petapixel.com/2014/04/02/sony-unveils-curved-sensor-technology/
2014: Sony launches a curved sensor camera… shaped like a perfume bottle https://www.youtube.com/watch?v=yFVGDBvgIV8 https://www.sony.net/SonyInfo/design/stories/dsc-kw1/01.html https://petapixel.com/2014/10/01/sony-confirms-perfume-bottle-camera-curved-sensor-curved-sensor-rx1-works/
2016: Canon patentshttps://www.canonnews.com/canon-patent-application-dual-pixel-curved-sensor https://petapixel.com/2016/12/09/canon-files-2-curved-sensor-patents-one-can-control/
Magnetic system to deform the sensor: https://www.canonrumors.com/patent-canon-continues-to-work-on-curved-sensor-technology/
Sony patented the first curved medium format sensor in 2017
Nikon patented a 35mm f/2 lens for a full frame camera with a curved sensor
Microsoft curved sensor: https://www.slrlounge.com/curved-sensors-microsoft/
December 2020, Curve-One https://www.curve-one.com/optical-design-fisheye-curve-one80/
Retina image from https://commons.wikimedia.org/wiki/File:201405_retina.png
Camera image from https://en.wikipedia.org/wiki/Macro_photography#/media/File:RevLensTeleMacro.png
So are the existing curves the ideal shape or we just can’t put a smaller radius on it?https://arxiv.org/pdf/1706.07041.pdf
“Fabricating an image sensor directly onto a curved substrate would require lithography tools for curved surfaces, a capability which is not yet commercially available . The most investigated methods for creating curved sensors pattern electronics onto flat, flexible substrates that can subsequently be deformed into a curved shape [8-15]. While successful in concept, these approaches have low pixel density due to substrate stretching, incompatibility with sophisticated active pixel CMOS or CCD arrays, and the inability to scale to small pixel pitches (less than 10 μm ) due to processing limitations.”
No need for extra lens elements to flatten the projected image from a lens, so simpler, cheaper lenses. Curve-One says “Save one third of the optics”
More compact lenses
Faster lenses with the same size. Curve-one says “down to f/1”
Corner-to-corner sharpness. Curve-one says “5X sharper on image edges”
Improved chromatism. Curve-one says 2.5X.
Requires the sensor and lens to be designed for each other…
No current ILC systems are designed for curved sensors, but the existing lens mount COULD work. But you’d need both new lenses AND new bodies AND the existing collection of lenses would work weirdly.
The more telephoto, the less it does
How it works
Sony makes flast sensor and then puts them on a machine that bends them (like a carpenter bending wood?)
The ideal curve would be different for different focal lengths… so you’ll see the greatest benefit with fixed-lens, prime-lens wide-angle cameras… like the Sony RX1. Which are NOT AT ALL POPULAR.
But it could make a GREAT street photography camera.. But If we can’t make a broadly interesting camera, prices will be VERY high, which further reduces the number that will sell, which makes them even less viable. And honestly who cares about corner sharpness or vignetting with street photography.
An astrophotography camera with a fixed 14mm f/1.0 lens or 20mm f/1.0 lens, corner-to-corner sharpness, and a specialized astro sensor sensor, would be game-changing.
But rumor has it Sony is releasing one, and they do make a lot of nichey cameras.
BUT there is one category of fixed-lens, prime wide-angle camera: the smartphone. And compact size and low-light capabilities are of PARAMOUNT importance to buyers.
Variable curved sensors
Flexible sensors… we have flexible displays, but flexible semiconductors are a different animal.
A Canon patent proposed using magnets to curve the sensor as needed, but they warn of increasing noise. https://www.canonrumors.com/patent-canon-continues-to-work-on-curved-sensor-technology/