The most obvious effect is that the telescope magnifies the image of the Moon causing the objects that subtend only one arcminute to our bare eyes to grow to subtend perhaps 30 or more arcminutes in t...The most obvious effect is that the telescope magnifies the image of the Moon causing the objects that subtend only one arcminute to our bare eyes to grow to subtend perhaps 30 or more arcminutes in the image we see in the telescope. From the expression, you can see that as long as the ratio of the wavelength to the diameter is small, the resolution of the telescope will be good (i.e., the telescope will be able to discern very small details).