Final answer:
The level of contrast that makes everything look close to the same level of brightness is when all the stars have the same luminosity or energy output.
Step-by-step explanation:
The level of contrast that makes everything look close to the same level of brightness is when all the stars have the same luminosity or energy output. In this case, if all the stars had the same luminosity, the closest stars would appear brighter because more of their light reaches our eyes, whereas the farther stars would appear dimmer because their light has spread out more before reaching our eyes.