You can image many stars and black holes as point sources without issues. For M87 you can even capture its huge particle jet using telephoto lens, digital camer

You can image many stars and black holes as point sources without issues. For M87 you can even capture its huge particle jet using telephoto lens, digital camera and small star tracker. This gives you their magnitudes, spectral lines, ability to detect planets passing in front of them etc. But if you want to resolve their image beyond point light it becomes very hard - there are hard physical limits on what size of aperture you need to resolve any detail. There are tricks to increase effective aperture by measuring phase of electromagnetic waves reaching antennas across the globe. It is called interferometry: https://en.wikipedia.org/wiki/Astronomical_interferometer https://en.wikipedia.org/wiki/Astronomical_interferometer Here is a list of the stars we have imaged beyond point source so far: https://en.wikipedia.org/wiki/List_of_stars_with_resolved_images https://en.wikipedia.org/wiki/List_of_stars_with_resolved_im... M87 is the first black hole imaged beyond point source.