Why Can't Cameras Capture Stars as Brightly as We See Them?
I. The Limitations of Camera Sensors
A camera's sensor is a 2D grid of pixels that convert light into electrical signals. Each pixel is a tiny piece of silicon that's designed to capture a specific amount of light. When a camera takes a picture, the light from the scene enters the lens and strikes the sensor. The sensor converts this light into an electrical signal that's then processed by the camera's electronics.
The sensitivity of a camera sensor is measured in ISO. The higher the ISO, the more sensitive the sensor is to light. However, increasing the ISO also increases the amount of noise in the image. Noise is a random variation in the electrical signal that can make the image look grainy or pixelated.
Most consumer cameras have an ISO range of 100 to 1600. This means that they can capture a wide range of light levels, but they will start to produce noticeable noise at higher ISOs.
II. The Brightness of Stars
The brightness of a star is measured in apparent magnitude. The lower the apparent magnitude, the brighter the star appears. The brightest star in the night sky, Sirius, has an apparent magnitude of -1.46. The faintest stars that can be seen with the naked eye have an apparent magnitude of about +6.
The brightness of a star depends on several factors, including its size, temperature, and distance from Earth. Larger stars are brighter than smaller stars, hotter stars are brighter than cooler stars, and closer stars are brighter than faraway stars.
III. Why Can't Cameras Capture Stars as Brightly as We See Them?
There are two main reasons why cameras can't capture stars as brightly as we see them.
The dynamic range of camera sensors is limited. The dynamic range of a sensor is the difference between the brightest and darkest parts of an image that can be captured without losing detail. The human eye has a very wide dynamic range, which allows us to see both bright stars and faint stars in the same scene. However, camera sensors have a much narrower dynamic range, which means that they can't capture both bright stars and faint stars in the same scene without losing detail.
The light from stars is very faint. The light from stars is very faint because it travels through a lot of space before it reaches Earth. The light from the brightest star in the night sky, Sirius, is only about 1/100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 watts. This is very faint, especially when compared to the light from the Sun, which is about 100,000,000,000,000,000,00
