In order to understand what Hubble sees, it is necessary to understand what astronomical telescopes do, and how they differ from the ones on the ground.
All telescopes collect light and magnify it .
When an image is magnified, it gets dimmer. This is because the light coming from the object is spread out over a larger area. If we try to magnify the image too much, it gets so dim when we look through the telescope we don't see anything at all. Astronomers have come up with several creative ways to obtain more light and make their images brighter. One way astronomers get around this problem is to make the telescope larger.