Does having larger pixel pitch (more microns) makes camera brighter at night?

Question

Let's say I have a full-frame camera A with pixel pitch 4 microns and a full-frame camera B with pixel pitch 6 microns. Will using same camera lens at same exposure f/2.0 and same ISO allow me to operate camera B at faster shutter speed e.g. 1/160s when in camera A i would have to resort to slower shutter speed of 1/60s?

In other words camera with sensor that has larger pixel size (e.g. 4 vs 6 microns) will see more light so can be set to lower shutter speed for the same photo?

EDIT: This is for shooting in very low light conditions i.e. street lights only.

in my understanding if yo have tiny window versus much larger window, bigger one allows more light in. and if we measure at same time limit i.e. set exposure to say 1/160s then smaller window lets less light in compared to bigger one?

Answer 1

ISO should mean the amount of light that must be received by the sensor to provide a proper exposure. As such, it is independent of pixel size. The 6 micron pitch sensels will receive 36/16 times more light each than the 4 micron sensels. If the sensors are of similar technology you could expect lower noise with the 6 micron sensels or to use a higher ISO with the same noise.

Answer 2

Sensors with large pixels are one possible way to make a camera usable at higher ISO settings without suffering from too much noise (this is the way eg the Sony A7s series and Nikon D3s/D4 do it). Other possible ways are: Using BSI and other improvements in sensor technology, averaging multiple smaller pixels into one each (can implicitly happen when displaying the image on a lower resolution display, or even visually on a very high resolution display with tiny pixels). So the idea is that eg a typical APS-C camera will be able to be set to ISO 3200 as a maximum before results get unusably noisy, a large pixel fullframe might be comparable at ISO 12800.

Generally, same object and illumination, same exposure triangle values (ISO included here), same brightness.

It is debated how precisely ISO values are actually matched between different camera vendors and models, but this is independent of the aforementioned matters.

Answer 3

The lens' aperture diameter (entrance pupil) determines how much light passes through the lens, and the lens' magnification (focal length) determines how spread out that light is; those two factors combine as the f#. Aperture (f#) alone determines the intensity/density (luminous flux) of the light at the image plane.

SS then determines for how long the image plane is illuminated with that intensity, and ISO adjusts the output brightness of the resulting exposure... exposure is size/area independent.

In your big window/little window analogy, the correct "window" is the size of the image plane/sensor, not the size of the pixels "behind" it. In your house you can stand behind a large window or a small window and it will make no difference; if you place your hand (small pixel) in the opening, or your face (larger pixel) in the opening, both will receive the same illumination (exposure/area); and that's *all that matters. But a larger window does pass more light overall; and similarly a larger image area/sensor receives more light as well. That last bit is often confused as "larger pixels" when discussing different sized sensors of the same resolution; but that is the wrong correlation.

DP review has a **good comparison tool. This is set for four Nikon cameras, low light, and the same output size. The top row is the 16MP D4 (7.3um) and the 46MP D850 (4.3um), both are FF sensors. The bottom row is of two smaller sensors.

The D4 image is a little out of focus which helps it a bit, but otherwise the noise in the top row is nearly the same (it will never be identical because it is random). The 1.5x crop factor D7500 image is noticeably noisier even though its' pixels are the same size as the D850 (4.2um); and the 2.7x V3 is much worse.

---

*at the extremes there can be notable differences in fill efficiencies that would make the larger pixels more effective; but that is essentially a non-factor in any realistic comparison.

** The comparisons reduce the exposure by changing the SS, so the ISO noise results may differ from reduced exposure due to lower light levels.