Are bigger pixels less noisy?

Started 5 months ago | Discussions
JahnG
JahnG Veteran Member • Posts: 3,340
Are bigger pixels less noisy?

Is there any consensus if pixel size influences how noisy a sensor is?

My questions are asked from the view of a ”for fun” photographer using APSC cameras and a ”1” camera, especially thinking about the noise level in low light photography.

In some DPR forums there are every now and then long threads about sensor size, pixel count and pixel size . Some experts or ”experts” write in DPR that sensors with bigger ”pixels” are less noisy, some think there is no difference.

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing?  (Some people in DPR  say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

In some technical magazines where also cameras are dealt with  they tend to think that sensors with bigger ”pixels” produce less noise?

What do you say in this forum:

  1. Is it possible to generally say that FF sensors with fewer and bigger ”pixels” are/ are not, less noisy (to any practical degree) than FF sensors with smaller ”pixels”. (Same for APSC sensors)
  2. Some DPR members also dispute whether FF sensors (regardless of pixel count ?) are less noisy (better for low light photography) than smaller sensors. One argument is that the existing difference in noisiness between FF cameras and small sensor cameras basically depends on the fact that small sensor cameras have smaller lenses and thus the lens collects less light. According to this  FF sensors and smaller sensors would be equally noisy?
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Eric Fossum
Eric Fossum Senior Member • Posts: 1,517
Re: Are bigger pixels less noisy?
15

JahnG wrote:

Is there any consensus if pixel size influences how noisy a sensor is?

My questions are asked from the view of a ”for fun” photographer using APSC cameras and a ”1” camera, especially thinking about the noise level in low light photography.

In some DPR forums there are every now and then long threads about sensor size, pixel count and pixel size . Some experts or ”experts” write in DPR that sensors with bigger ”pixels” are less noisy, some think there is no difference.

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

In some technical magazines where also cameras are dealt with they tend to think that sensors with bigger ”pixels” produce less noise?

What do you say in this forum:

  1. Is it possible to generally say that FF sensors with fewer and bigger ”pixels” are/ are not, less noisy (to any practical degree) than FF sensors with smaller ”pixels”. (Same for APSC sensors)
  2. Some DPR members also dispute whether FF sensors (regardless of pixel count ?) are less noisy (better for low light photography) than smaller sensors. One argument is that the existing difference in noisiness between FF cameras and small sensor cameras basically depends on the fact that small sensor cameras have smaller lenses and thus the lens collects less light. According to this FF sensors and smaller sensors would be equally noisy?

I might be considered an expert...

Bigger pixels are almost never less noisy than smaller pixels.

But you might be confused about noise vs. signal-to-noise ratio.

More light, more noise, and better SNR - pixel size does not matter since the noise is due to the fundamental "noisy" nature of light.

Generally, bigger pixels collect more light (i.e. photons) for the same F-no. so their noise-to-signal is less which is probably what you are really thinking about.

-EF

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alanr0 Senior Member • Posts: 2,472
Are recent sensors less noisy?
5

JahnG wrote:

Is there any consensus if pixel size influences how noisy a sensor is?

My questions are asked from the view of a ”for fun” photographer using APSC cameras and a ”1” camera, especially thinking about the noise level in low light photography.

In some DPR forums there are every now and then long threads about sensor size, pixel count and pixel size . Some experts or ”experts” write in DPR that sensors with bigger ”pixels” are less noisy, some think there is no difference.

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

In some technical magazines where also cameras are dealt with they tend to think that sensors with bigger ”pixels” produce less noise?

What do you say in this forum:

  1. Is it possible to generally say that FF sensors with fewer and bigger ”pixels” are/ are not, less noisy (to any practical degree) than FF sensors with smaller ”pixels”. (Same for APSC sensors)
  2. Some DPR members also dispute whether FF sensors (regardless of pixel count ?) are less noisy (better for low light photography) than smaller sensors. One argument is that the existing difference in noisiness between FF cameras and small sensor cameras basically depends on the fact that small sensor cameras have smaller lenses and thus the lens collects less light. According to this FF sensors and smaller sensors would be equally noisy?

As Eric Fossum notes, there are well-established practical and theoretical reasons why larger pixels are at least as noisy as smaller pixels.

For many recent cameras, the differences are typically very small, and under typical circumstances sensor read noise will be much less than the unavoidable Poisson-distributed noise associated with photon arrival statistics.

Read noise can be as low as 1 electron RMS (or even less).  For comparison, if you capture (on average) as few as 25 photons per pixel in the shadow regions of your image, the Poisson standard deviation in the signal will be 5 electrons, and an additional 1e- rms will increase the noise by only around 2%.

For such a sensor, read noise becomes significant only when the signal to noise ratio due to photon statistics is already very poor.

Regarding sensor size, a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light.  If you are limited by the size and weight of the lens, then sensor size will not make much difference.

A much clearer trend is that sensors from 5 or more years ago are noisier than the best modern sensors. If you are interested in historical trends:

There are measurements of older sensors on Roger Clark's Clarkvision site.

The sensorgen site is no longer maintained, but the information extracted from DxO is still available on WaybackMachine.

Bill Claff includes results for recent cameras on his photonstophotos site.

So, in the link above, the Nikon D200 had a read noise of 9.1 e-, while the D500 is reported as only 1 e-.

If you are looking for quantitative evidence, it is essential to compare sensors of comparable technological maturity.

There are trade-offs between read noise, read-out speed (less of a concern with column parallel read-out) and sensor full well capacity (which impacts dynamic range).  Some sensors (notably from Sony) exploit a technique developed by Aptina to switch between a high dynamic range mode at low ISO, and a low noise mode at higher ISO speeds.  Bill Claff discusses this and presents measurements here.

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Alan Robinson

JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are bigger pixels less noisy?

Eric Fossum wrote:

JahnG wrote:

Is there any consensus if pixel size influences how noisy a sensor is?

My questions are asked from the view of a ”for fun” photographer using APSC cameras and a ”1” camera, especially thinking about the noise level in low light photography.

In some DPR forums there are every now and then long threads about sensor size, pixel count and pixel size . Some experts or ”experts” write in DPR that sensors with bigger ”pixels” are less noisy, some think there is no difference.

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

In some technical magazines where also cameras are dealt with they tend to think that sensors with bigger ”pixels” produce less noise?

What do you say in this forum:

  1. Is it possible to generally say that FF sensors with fewer and bigger ”pixels” are/ are not, less noisy (to any practical degree) than FF sensors with smaller ”pixels”. (Same for APSC sensors)
  2. Some DPR members also dispute whether FF sensors (regardless of pixel count ?) are less noisy (better for low light photography) than smaller sensors. One argument is that the existing difference in noisiness between FF cameras and small sensor cameras basically depends on the fact that small sensor cameras have smaller lenses and thus the lens collects less light. According to this FF sensors and smaller sensors would be equally noisy?

I might be considered an expert...

Bigger pixels are almost never less noisy than smaller pixels.

But you might be confused about noise vs. signal-to-noise ratio.

More light, more noise, and better SNR - pixel size does not matter since the noise is due to the fundamental "noisy" nature of light.

Generally, bigger pixels collect more light (i.e. photons) for the same F-no. so their noise-to-signal is less which is probably what you are really thinking about.

-EF

Thank you very much

Jahn

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JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are recent sensors less noisy?

alanr0 wrote:

JahnG wrote:

Is there any consensus if pixel size influences how noisy a sensor is?

My questions are asked from the view of a ”for fun” photographer using APSC cameras and a ”1” camera, especially thinking about the noise level in low light photography.

In some DPR forums there are every now and then long threads about sensor size, pixel count and pixel size . Some experts or ”experts” write in DPR that sensors with bigger ”pixels” are less noisy, some think there is no difference.

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

In some technical magazines where also cameras are dealt with they tend to think that sensors with bigger ”pixels” produce less noise?

What do you say in this forum:

  1. Is it possible to generally say that FF sensors with fewer and bigger ”pixels” are/ are not, less noisy (to any practical degree) than FF sensors with smaller ”pixels”. (Same for APSC sensors)
  2. Some DPR members also dispute whether FF sensors (regardless of pixel count ?) are less noisy (better for low light photography) than smaller sensors. One argument is that the existing difference in noisiness between FF cameras and small sensor cameras basically depends on the fact that small sensor cameras have smaller lenses and thus the lens collects less light. According to this FF sensors and smaller sensors would be equally noisy?

As Eric Fossum notes, there are well-established practical and theoretical reasons why larger pixels are at least as noisy as smaller pixels.

For many recent cameras, the differences are typically very small, and under typical circumstances sensor read noise will be much less than the unavoidable Poisson-distributed noise associated with photon arrival statistics.

Read noise can be as low as 1 electron RMS (or even less). For comparison, if you capture (on average) as few as 25 photons per pixel in the shadow regions of your image, the Poisson standard deviation in the signal will be 5 electrons, and an additional 1e- rms will increase the noise by only around 2%.

For such a sensor, read noise becomes significant only when the signal to noise ratio due to photon statistics is already very poor.

Regarding sensor size, a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light. If you are limited by the size and weight of the lens, then sensor size will not make much difference.

A much clearer trend is that sensors from 5 or more years ago are noisier than the best modern sensors. If you are interested in historical trends:

There are measurements of older sensors on Roger Clark's Clarkvision site.

The sensorgen site is no longer maintained, but the information extracted from DxO is still available on WaybackMachine.

Bill Claff includes results for recent cameras on his photonstophotos site.

So, in the link above, the Nikon D200 had a read noise of 9.1 e-, while the D500 is reported as only 1 e-.

If you are looking for quantitative evidence, it is essential to compare sensors of comparable technological maturity.

There are trade-offs between read noise, read-out speed (less of a concern with column parallel read-out) and sensor full well capacity (which impacts dynamic range). Some sensors (notably from Sony) exploit a technique developed by Aptina to switch between a high dynamic range mode at low ISO, and a low noise mode at higher ISO speeds. Bill Claff discusses this and presents measurements here.

Thank you very much for the information.

PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

Jahn

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bclaff Forum Pro • Posts: 12,095
Re: Are recent sensors less noisy?

JahnG wrote:
...
PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

You may be intuiting something like a focal reducer ("SpeedBooster")
This is rear converter optics that "concentrates" an image circle to a smaller image circle which reduces the focal length and the f-number of the resulting combination.

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Bill ( Your trusted source for independent sensor data at PhotonsToPhotos )

ahaslett
ahaslett Veteran Member • Posts: 8,854
Re: Are bigger pixels less noisy?

I'm humbled by the level of expertise of your respondents.

I don't think you have defined your question unambiguously - do you mean:

a) For a sensor of given size, what is the effect on noise of having more pixels, or

b) For a given number of pixels, what is the effect of sensor size?

My interpretation of the responses is that (a) has little effect but (b) gives the potential for lower noise, depending on how you use the camera.

I'd also say that non-linear noise reduction typically benefits from more resolution in terms of preserving detail while reducing the appearance of noise.

Your question about the impact of aperture is related to the potential for lower noise (ie more light).  You might find this https://www.dpreview.com/learn/2799100497/equivalence-in-a-nutshell useful in understanding the effect of sensor size and aperture on image properties.  In order to benefit from a larger sensor, you need to either accept shallower depth of field or longer exposure times.  As a landscape shooter, you can often accept longer exposure.  This can have real noise benefits, for example in blue skies.

The idea that larger pixels give better images at constant sensor size (ie fewer pixels) seems to come from looking at images at 100%, ie greater magnification of the higher resolution image.

Andrew

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D Cox Forum Pro • Posts: 29,583
Re: Are bigger pixels less noisy?

A sensor with smaller pixels can record both noise and signal (image details) at higher spatial frequencies.

On (for instance) an area of clear blue sky in a landscape, when viewed at a high magnification, you might see more noise. In an area of the image with leaves and branches, the signal (differences between each patch of the image and its neighbours) will swamp the noise, assuming the lens is of high quality.

Note that viewing at "100%" will give different magnifications for different pixel sizes. For comparison, it would be best to make same size big prints and examine them closely.

Don Cox

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Sigma fp
D Cox Forum Pro • Posts: 29,583
Re: Are recent sensors less noisy?

JahnG wrote:

alanr0 wrote:

JahnG wrote:

Is there any consensus if pixel size influences how noisy a sensor is?

My questions are asked from the view of a ”for fun” photographer using APSC cameras and a ”1” camera, especially thinking about the noise level in low light photography.

In some DPR forums there are every now and then long threads about sensor size, pixel count and pixel size . Some experts or ”experts” write in DPR that sensors with bigger ”pixels” are less noisy, some think there is no difference.

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

In some technical magazines where also cameras are dealt with they tend to think that sensors with bigger ”pixels” produce less noise?

What do you say in this forum:

  1. Is it possible to generally say that FF sensors with fewer and bigger ”pixels” are/ are not, less noisy (to any practical degree) than FF sensors with smaller ”pixels”. (Same for APSC sensors)
  2. Some DPR members also dispute whether FF sensors (regardless of pixel count ?) are less noisy (better for low light photography) than smaller sensors. One argument is that the existing difference in noisiness between FF cameras and small sensor cameras basically depends on the fact that small sensor cameras have smaller lenses and thus the lens collects less light. According to this FF sensors and smaller sensors would be equally noisy?

As Eric Fossum notes, there are well-established practical and theoretical reasons why larger pixels are at least as noisy as smaller pixels.

For many recent cameras, the differences are typically very small, and under typical circumstances sensor read noise will be much less than the unavoidable Poisson-distributed noise associated with photon arrival statistics.

Read noise can be as low as 1 electron RMS (or even less). For comparison, if you capture (on average) as few as 25 photons per pixel in the shadow regions of your image, the Poisson standard deviation in the signal will be 5 electrons, and an additional 1e- rms will increase the noise by only around 2%.

For such a sensor, read noise becomes significant only when the signal to noise ratio due to photon statistics is already very poor.

Regarding sensor size, a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light. If you are limited by the size and weight of the lens, then sensor size will not make much difference.

A much clearer trend is that sensors from 5 or more years ago are noisier than the best modern sensors. If you are interested in historical trends:

There are measurements of older sensors on Roger Clark's Clarkvision site.

The sensorgen site is no longer maintained, but the information extracted from DxO is still available on WaybackMachine.

Bill Claff includes results for recent cameras on his photonstophotos site.

So, in the link above, the Nikon D200 had a read noise of 9.1 e-, while the D500 is reported as only 1 e-.

If you are looking for quantitative evidence, it is essential to compare sensors of comparable technological maturity.

There are trade-offs between read noise, read-out speed (less of a concern with column parallel read-out) and sensor full well capacity (which impacts dynamic range). Some sensors (notably from Sony) exploit a technique developed by Aptina to switch between a high dynamic range mode at low ISO, and a low noise mode at higher ISO speeds. Bill Claff discusses this and presents measurements here.

Thank you very much for the information.

PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

Jahn

Just take your f/0.9 lens from your 24x36 camera and adapt it to your M4/3 camera.

I can't see any way in which a larger sensor "allows" you to use a lens with a larger entrance pupil, or a smaller sensor forbids it.

Don Cox

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spider-mario
spider-mario Contributing Member • Posts: 912
Re: Are recent sensors less noisy?

D Cox wrote:

I can't see any way in which a larger sensor "allows" you to use a lens with a larger entrance pupil, or a smaller sensor forbids it.

It does if you qualify the statement with “for a given angle of view”. A larger sensor can achieve that angle of view with a greater focal length, thereby not requiring as low an f-ratio for a certain entrance pupil size.

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alanr0 Senior Member • Posts: 2,472
NA, f-number & Speed Boosters
3

JahnG wrote:

alanr0 wrote:

<snip>

Regarding sensor size, a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light. If you are limited by the size and weight of the lens, then sensor size will not make much difference.

<snip>

Thank you very much for the information.

PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

spider-mario reminds me that statement needs qualifying.

Bill Claff points out that one way to concentrate the light onto a smaller sensor, while keeping the same field of view is to use a device such as Metabones' speed booster.  This keeps the entrance pupil of the lens unchanged, but reduces the focal length, image circle and the f-number by the same factor.

Reduction factors typically vary between 0.71 and 0.50.  There are both practical and theoretical limits on how far you can concentrate the light.  The practical limits relate to vignetting and aberrations. For the 0.71x converter, Metabones specify f/1.26 as the maximum input aperture for f/0.9 with the converter attached, and f/1.2 for the 0.5x converter and an resultant f/0.666 (probably with some vignetting).

The theoretical limits are more fundamental.  For a well-corrected lens in air, it is not possible for the numerical aperture to be greater than 1.0, or equivalently, the f-number cannot be less than 0.5.

So if you have a 200 mm f/2 lens with a 100 mm entrance pupil, you cannot stack speed boosters indefinitely.  At the theoretical minimum f/0.5, focal length will be 50 mm, so your 1/2.3 inch sensor will have a 9 degree diagonal field of view.

Start with a larger diameter aperture, and you hit f/0.5 at a longer focal length, and a smaller field of view.  In practice, mechanical constraints and high off-axis lens aberrations will kick in before you reach the theoretical limit.

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Alan Robinson

J A C S
J A C S Forum Pro • Posts: 19,299
Re: Are recent sensors less noisy?
1

JahnG wrote:

PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

To replicate my 50/1.2 on FF, you would need something like an 8.9/0.21 lens, which would be faster than the theoretical limit of f/0.5, not to mention the practical one f/1 or so.

JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are recent sensors less noisy?

bclaff wrote:

JahnG wrote:
...
PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

You may be intuiting something like a focal reducer ("SpeedBooster")
This is rear converter optics that "concentrates" an image circle to a smaller image circle which reduces the focal length and the f-number of the resulting combination.

Ok, thanks.

so they do exist. So for instance an APSC to MF4/3 adapter that I have sometimes heard about is something like that

Jahn

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JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are bigger pixels less noisy?

D Cox wrote:

A sensor with smaller pixels can record both noise and signal (image details) at higher spatial frequencies.

On (for instance) an area of clear blue sky in a landscape, when viewed at a high magnification, you might see more noise. In an area of the image with leaves and branches, the signal (differences between each patch of the image and its neighbours) will swamp the noise, assuming the lens is of high quality.

Note that viewing at "100%" will give different magnifications for different pixel sizes. For comparison, it would be best to make same size big prints and examine them closely.

Don Cox

Very true, thanks

Jahn

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JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: NA, f-number & Speed Boosters

alanr0 wrote:

JahnG wrote:

alanr0 wrote:

<snip>

Regarding sensor size, a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light. If you are limited by the size and weight of the lens, then sensor size will not make much difference.

<snip>

Thank you very much for the information.

PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

spider-mario reminds me that statement needs qualifying.

Bill Claff points out that one way to concentrate the light onto a smaller sensor, while keeping the same field of view is to use a device such as Metabones' speed booster. This keeps the entrance pupil of the lens unchanged, but reduces the focal length, image circle and the f-number by the same factor.

Reduction factors typically vary between 0.71 and 0.50. There are both practical and theoretical limits on how far you can concentrate the light. The practical limits relate to vignetting and aberrations. For the 0.71x converter, Metabones specify f/1.26 as the maximum input aperture for f/0.9 with the converter attached, and f/1.2 for the 0.5x converter and an resultant f/0.666 (probably with some vignetting).

The theoretical limits are more fundamental. For a well-corrected lens in air, it is not possible for the numerical aperture to be greater than 1.0, or equivalently, the f-number cannot be less than 0.5.

So if you have a 200 mm f/2 lens with a 100 mm entrance pupil, you cannot stack speed boosters indefinitely. At the theoretical minimum f/0.5, focal length will be 50 mm, so your 1/2.3 inch sensor will have a 9 degree diagonal field of view.

Start with a larger diameter aperture, and you hit f/0.5 at a longer focal length, and a smaller field of view. In practice, mechanical constraints and high off-axis lens aberrations will kick in before you reach the theoretical limit.

Thank you for the interesting information.

Jahn

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JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are recent sensors less noisy?

J A C S wrote:

JahnG wrote:

PS, You say "a larger sensor does allow you to use a lens with a larger entrance pupil and gather more light". From that I get a "foolish" thought. Might it (theoretically?) be possible to build a low light camera using big entrant lenses collecting much light and have all this light focused on a minimal 1/2.3 sensor?? In a way like an astronomical telescope.

To replicate my 50/1.2 on FF, you would need something like an 8.9/0.21 lens, which would be faster than the theoretical limit of f/0.5, not to mention the practical one f/1 or so.

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Iliah Borg Forum Pro • Posts: 28,677
Re: Are bigger pixels less noisy?
3

JahnG wrote:

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

Suppose 1 large pixel collects the same light as four smaller pixels occupying the same space. Is it possible?

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JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are bigger pixels less noisy?

ahaslett wrote:

I'm humbled by the level of expertise of your respondents.

I don't think you have defined your question unambiguously - do you mean:

a) For a sensor of given size, what is the effect on noise of having more pixels, or

b) For a given number of pixels, what is the effect of sensor size?

My interpretation of the responses is that (a) has little effect but (b) gives the potential for lower noise, depending on how you use the camera.

I'd also say that non-linear noise reduction typically benefits from more resolution in terms of preserving detail while reducing the appearance of noise.

Your question about the impact of aperture is related to the potential for lower noise (ie more light). You might find this https://www.dpreview.com/learn/2799100497/equivalence-in-a-nutshell useful in understanding the effect of sensor size and aperture on image properties. In order to benefit from a larger sensor, you need to either accept shallower depth of field or longer exposure times. As a landscape shooter, you can often accept longer exposure. This can have real noise benefits, for example in blue skies.

The idea that larger pixels give better images at constant sensor size (ie fewer pixels) seems to come from looking at images at 100%, ie greater magnification of the higher resolution image.

Andrew

Yes, high level of knowledge in the answers/comments.

Well, actuall both your a) and b) applies, although I formulated my question in another way. I wished to have expert comments. (In other forums of DPR I have seen all kind of contradicting views about these matters)

Thanks for your interesting comments about non-linear noise reduction. I seldom use noise reduction in my PaintShopPro (PSP) program. (I'm shooting jpeg). The effect seems much too much to just blur the pictures!  I will start looking for "non-linear noise reduction" to be combined with PSP.

Thanks for the link.

The "aperture question" was a sudden thought if it would be possible to that way collect much light on a small sensor, (thinking about astronomical telescopes having small diameter "magnifying glases") I lerned that a "focal reducer" in a way resembles what I asked about. (I hadn't heard about focal reducers earlier)

Jahn

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JahnG
OP JahnG Veteran Member • Posts: 3,340
Re: Are bigger pixels less noisy?

Iliah Borg wrote:

JahnG wrote:

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

Suppose 1 large pixel collects the same light as four smaller pixels occupying the same space. Is it possible?

Sounds logical.

The combined light collecting area of a FF sensor might (roughly) be the same, regardless of if there are 20M bigger or 50M smaller pixels.

But how about the combined read noise of 50M pixels compared to the combined read noise of 20M pixels. One might thus think that the sensor having only 40% pixel count would have much less combined read noise? (Or shouldn't we sum read noise?).

If however even a higher  combined read noise is small compared to the irregular behavior of light itself, then the pixel count wouldn't matter.

Jahn

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J A C S
J A C S Forum Pro • Posts: 19,299
Re: Are bigger pixels less noisy?

JahnG wrote:

Iliah Borg wrote:

JahnG wrote:

Camera manufactors like Canon, Sony, (Panasonic) have made ”low noise” cameras with less and bigger ”pixels”. Do the manufactors not know what they are doing? (Some people in DPR say that such cameras are manufactored because the customers expect that sensors with bigger ””pixels” would be less noisy?)

Suppose 1 large pixel collects the same light as four smaller pixels occupying the same space. Is it possible?

Sounds logical.

The combined light collecting area of a FF sensor might (roughly) be the same, regardless of if there are 20M bigger or 50M smaller pixels.

But how about the combined read noise of 50M pixels compared to the combined read noise of 20M pixels. One might thus think that the sensor having only 40% pixel count would have much less combined read noise? (Or shouldn't we sum read noise?).

The engineers may chime in why - but what I see is that smaller pixels have smaller read noise. In the end, read noise per unit area seems weakly dependent on pixel size.

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