/sci/ - Science & Math

No consumer grade telescope, let alone a small camera lens can resolve an image of a distant star and it has nothing to do with the quality of the optics like some of you have stated but about the size of the telescope mirror or lens. It's about angular resolution.
Angular resolution is the ability of an optical system to separate point light sources. Lets say we have two stars on the night sky that are really close together. With a really small telescope those two stars will look like a single point of light no matter how much you magnify the image and if you magnify the image enough you will see that the point of light is surrounded by faint concentric rings. This is what's known as an airy disc which is just an interference pattern of light and it's the same principle as that experiment were you shine laser light through a small slit. The slit is the lens or mirror in this case. Diffraction of light. Anyway, lets switch to a bigger telescope. Suddenly you can differentiate the two stars from each other because you have increased the optical opening and thus increased the angular resolution.
Stars are such tiny objects and you need a REALLY big telescope in order to resolve an image, otherwise it will just turn into an interference pattern on your camera sensor or retina (if you are visually observing through the telescope) and if you put the airy disc out of focus, which is what the stars are in those p900 videos, the interference pattern will be more pronounced.

This is why you get a better view of Jupiter for example or some of the smaller craters of the Moon through a bigger telescope than a smaller one and it's also the principle behind why you can see the ISS with your naked eye even though it's far away. You're not actually resolving an image of the space station with your eyes because the human pupils are too small, you're just looking at an airy disc.