Curved sensors - good or a bad development ?

[stevo23]

If a curved sensor is the answer, what is the question?

You mean the ultimate question?

It depends on how ultimate you want to go. It could go all the way to the top.

 

[Turbguy1]

While the possibility of curved sensors could a boon to some instances, keep in mind that:

A FLAT SURFACE IS ONE SPECIAL CASE OF A CURVED SURFACE.

All curved surfaces can be considered "special cases". The FLAT solid surface is the simplest and easiest to produce. A curved solid surface, not so easy, if you have to have EXACTLY the correct curve (and there's an infinite number of them, spherical, cylindrical, parabolic and a whole host of complex mathematical surfaces).

That said, lens design/manufacture might be easier if you could deviate the focal plane from "flat"...

 

[TacticDesigns]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!

 

[FrancoD]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

 

[Joe Pineapples II]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

J.

 

[Mark S Abeln]

I'd assume that in most cases, the image would be corrected to rectilinear

Animal and human eyes have curved sensors and low element-count lenses, yet my view appears to be rectilinear. Lines that are straight in real life appear to be straight to my eye.

 

[Turbguy1]

And yje human eye is only "sharp" in a narrow field of view.

And there a lot of image processing going on...

 

[rurikw]

While the possibility of curved sensors could a boon to some instances, keep in mind that:

A FLAT SURFACE IS ONE SPECIAL CASE OF A CURVED SURFACE.

All curved surfaces can be considered "special cases". The FLAT solid surface is the simplest and easiest to produce. A curved solid surface, not so easy, if you have to have EXACTLY the correct curve (and there's an infinite number of them, spherical, cylindrical, parabolic and a whole host of complex mathematical surfaces).

That said, lens design/manufacture might be easier if you could deviate the focal plane from "flat"...

 

[stevo23]

And yje human eye is only "sharp" in a narrow field of view.

Sharp or "sharp"? What's the difference?

And there a lot of image processing going on...

How would we know?

 

[TacticDesigns]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Take care & Happy Shooting!

J.

--
My Personal Flickr Favs . . .

My Favs

Some of my personal favourites from over the years . . .

www.flickr.com

[FL][RP][LS]

 

[TacticDesigns]

I'd assume that in most cases, the image would be corrected to rectilinear

Animal and human eyes have curved sensors and low element-count lenses, yet my view appears to be rectilinear. Lines that are straight in real life appear to be straight to my eye.

+1

Good example.

Is there an example of what image gets projected onto the back of an eye? . . . like a simulation?

That would be pretty cool to see.

And then see how that is translated into what we see in our minds eye, so to speak.

Does anyone know of a sample of that?

Take care & Happy Shooting!

 

[stevo23]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

 

[Mark S Abeln]

And there a lot of image processing going on...

How would we know?

Half the cerebral cortex is involved in image processing.

 

[stevo23]

And there a lot of image processing going on...

How would we know?

Half the cerebral cortex is involved in image processing.

I question how we know even that and to what extent. But given that, it still begs the question as to exactly what is being processed/filled in and what our eyes are doing optically.

 

[TacticDesigns]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Things like chromatic aberration and distortion?

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

I guess I'm trying to understand what you mean by the result will be a naturally flat image?

Do you mean that it will be a cleaner image (less aberrations), but the image still needs to go through digital processing / projection in order to be printed as a flat image, like a print?

Thank you!

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .

My Favs

Some of my personal favourites from over the years . . .

www.flickr.com

[FL][RP][LS]

 

[stevo23]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Things like chromatic aberration and distortion?

And spherical aberration and coma etc.

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

I guess I'm trying to understand what you mean by the result will be a naturally flat image?

Do you mean that it will be a cleaner image (less aberrations), but the image still needs to go through digital processing / projection in order to be printed as a flat image, like a print?

What I'm saying is that it will be flat and not require any flattening - at least this is my expectation. IE, a lens wants to project an image that isn't flat. But if we meet that with a curved sensor, then the image will be flat.

So we would design lenses that are happily not projecting a flat image in such a way that the curvature of the image matches that of the image sensor. So now, where you would have had poor edge performance, we've moved the sensor surface a bit to cure that. (For instance.)

 

[TacticDesigns]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Things like chromatic aberration and distortion?

And spherical aberration and coma etc.

+1

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

I guess I'm trying to understand what you mean by the result will be a naturally flat image?

Do you mean that it will be a cleaner image (less aberrations), but the image still needs to go through digital processing / projection in order to be printed as a flat image, like a print?

What I'm saying is that it will be flat and not require any flattening - at least this is my expectation. IE, a lens wants to project an image that isn't flat. But if we meet that with a curved sensor, then the image will be flat.

+1

So we would design lenses that are happily not projecting a flat image in such a way that the curvature of the image matches that of the image sensor. So now, where you would have had poor edge performance, we've moved the sensor surface a bit to cure that. (For instance.)

Ok. I think we are using "flat" at different parts of the workflow.

I think you are referring to "flat" when the lens projects the image onto the sensor. In which case, yes . . . a lens designed to project onto a curved sensor could project a cleaner image.

The flat I'm talking about is when you take the image captured from the curved sensor and try to print it on flat piece of paper.

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .

My Favs

Some of my personal favourites from over the years . . .

www.flickr.com

[FL][RP][LS]

 

[stevo23]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Things like chromatic aberration and distortion?

And spherical aberration and coma etc.

+1

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

I guess I'm trying to understand what you mean by the result will be a naturally flat image?

Do you mean that it will be a cleaner image (less aberrations), but the image still needs to go through digital processing / projection in order to be printed as a flat image, like a print?

What I'm saying is that it will be flat and not require any flattening - at least this is my expectation. IE, a lens wants to project an image that isn't flat. But if we meet that with a curved sensor, then the image will be flat.

+1

So we would design lenses that are happily not projecting a flat image in such a way that the curvature of the image matches that of the image sensor. So now, where you would have had poor edge performance, we've moved the sensor surface a bit to cure that. (For instance.)

Ok. I think we are using "flat" at different parts of the workflow.

I think you are referring to "flat" when the lens projects the image onto the sensor. In which case, yes . . . a lens designed to project onto a curved sensor could project a cleaner image.

The flat I'm talking about is when you take the image captured from the curved sensor and try to print it on flat piece of paper.

I'm lost with that question. At the very edge, the image will be sharp and free from aberration in theory and so in the center - the sensor is just transmitting pulses for a given location. Are you thinking as if you would flatten out the sensor and therefore have gaps in the image that need filling in? I guess I'm assuming the sensor is curved after the photo sites have been placed. Maybe not?

 

[TacticDesigns]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

Take care & Happy Shooting!


--
My Personal Flickr Favs . . .
http://www.flickr.com/photos/tacticdesigns/sets/72157631300869284/
[FL][RP][LS]

this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Things like chromatic aberration and distortion?

And spherical aberration and coma etc.

+1

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

I guess I'm trying to understand what you mean by the result will be a naturally flat image?

Do you mean that it will be a cleaner image (less aberrations), but the image still needs to go through digital processing / projection in order to be printed as a flat image, like a print?

What I'm saying is that it will be flat and not require any flattening - at least this is my expectation. IE, a lens wants to project an image that isn't flat. But if we meet that with a curved sensor, then the image will be flat.

+1

So we would design lenses that are happily not projecting a flat image in such a way that the curvature of the image matches that of the image sensor. So now, where you would have had poor edge performance, we've moved the sensor surface a bit to cure that. (For instance.)

Ok. I think we are using "flat" at different parts of the workflow.

I think you are referring to "flat" when the lens projects the image onto the sensor. In which case, yes . . . a lens designed to project onto a curved sensor could project a cleaner image.

The flat I'm talking about is when you take the image captured from the curved sensor and try to print it on flat piece of paper.

I'm lost with that question. At the very edge, the image will be sharp and free from aberration in theory and so in the center - the sensor is just transmitting pulses for a given location. Are you thinking as if you would flatten out the sensor and therefore have gaps in the image that need filling in? I guess I'm assuming the sensor is curved after the photo sites have been placed. Maybe not?

It actually wasn't a question.

I understand that we are using the word "flat" in different ways.

I agree with everything you say.

My use of the word "flat" is when you take that image that has been captured and you try to print it on a flat piece of paper. That's all.

I was just trying to understand how you were using the word "flat".

Take care & Happy Shooting!


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[stevo23]

I've just read what has been posted on this site about curved sensors.

Haven't really read too much.

But 2 questions.

1. Would curved sensors work well with trying to capture 180 or 360 degree pictures?

[...]

You're thinking of those old panoramic cameras where the film was held on a semi-circular arc and the lens was rotated mechanically. These are very subtly curved sensors which compensate for the field curvature, rather than using optical elements in the lens to correct it. This Wikipedia page gives some examples:

https://en.wikipedia.org/wiki/Petzval_field_curvature

J.

+1

Those panoramic cameras are exactly what I was thinking.

With the film, you could only bend (roll) it in one direction (axis).

But, with a curved sensor, it would be like you were rolling the film (sensor) in all directions.

Would that be the case?

Get on curved sensor and you've got ~180 degrees. Have 2 sensors (one on each side of the camera, like the Ricoh Theta) and you've got 360 degrees, but better IQ?

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this is the Sony curved sensor discussed here :

+1

Yes. I guess not as wrapped as the film was in the old panoramic cameras.

But if this gives some sort of advantage to IQ with wide angle lenses, then would this be a progression for wide angle cameras, including fisheye or panoramic cameras?

Yes - in the panoramic film cameras the film remained as what the mathematicians would call a developable surface, i.e. you could roll it out flat without stretching or creasing it - they would say that the film had zero Gaussian curvature - whereas the surface of these sensors it is really a curved surface; though with the current technology you clearly can't bend it very much.

+1

What is the benefit of being a "developable surface"?

I can see that because the sensor is manufactured into a curve (somewhere along the process) and then it's shape becomes set, it can't be straightened.

But . . . since the sensor records data, it is possible to "flatten" the representation of that data . . . it can be projected digitally onto a flat surface.

You don't need to flatten the data.

So, it may not be physically possible to flatten the sensor into a developable surface, but digitally it is possible? Yes? So, sort of a digital version of developable surface?

Not what's going on I think. In this case, the lens and the sensor will be matched and the resulting image will be flat field. The point is that a lens already struggles to be flat and we do many corrections to compensate for this.

Things like chromatic aberration and distortion?

And spherical aberration and coma etc.

+1

Now, there will be fewer corrections required because we'll stop trying to make it project a ruler flat image. Instead, we'll let it have a curve that matches the curve of the sensor. The result will be a naturally flat image.

I guess I'm trying to understand what you mean by the result will be a naturally flat image?

Do you mean that it will be a cleaner image (less aberrations), but the image still needs to go through digital processing / projection in order to be printed as a flat image, like a print?

What I'm saying is that it will be flat and not require any flattening - at least this is my expectation. IE, a lens wants to project an image that isn't flat. But if we meet that with a curved sensor, then the image will be flat.

+1

So we would design lenses that are happily not projecting a flat image in such a way that the curvature of the image matches that of the image sensor. So now, where you would have had poor edge performance, we've moved the sensor surface a bit to cure that. (For instance.)

Ok. I think we are using "flat" at different parts of the workflow.

I think you are referring to "flat" when the lens projects the image onto the sensor. In which case, yes . . . a lens designed to project onto a curved sensor could project a cleaner image.

The flat I'm talking about is when you take the image captured from the curved sensor and try to print it on flat piece of paper.

I'm lost with that question. At the very edge, the image will be sharp and free from aberration in theory and so in the center - the sensor is just transmitting pulses for a given location. Are you thinking as if you would flatten out the sensor and therefore have gaps in the image that need filling in? I guess I'm assuming the sensor is curved after the photo sites have been placed. Maybe not?

It actually wasn't a question.

I understand that we are using the word "flat" in different ways.

I agree with everything you say.

My use of the word "flat" is when you take that image that has been captured and you try to print it on a flat piece of paper. That's all.

I was just trying to understand how you were using the word "flat".

No, we're using the word the same way, but I'm not sure why the question about printing on a piece of paper. I not seeing how it's a problem. It's possible that I'm overlooking something and over simplifying.