It's defianately something I would attempt once I have got a bit more used to the scope in operation. I had a look through your post on removing the scattered light and found it very interesting and creative. As for coma, I've never noticed it: I'm too busy looking at what's at the centre of field, not the edge. Since my real business is looking at faint fuzzies, it doesn't matter too much to me either way. The spikes can even be useful in the case of splitting very close double stars, since by throwing light out into spikes, the star's diffraction disc is made smaller. There are of course those who think spikes around stars are very pretty and part of the appeal. But even with spikes, a Newtonian can give very good contrast - I'm certainly happy enough with my SkyWatcher now. Edited by Eddgie, 30 October 2020 - 11:05 AM. A long exposure will show diffraction spikes even on stars you would not be able to see visually. No doubt you have seen astronomical photographs where the bright stars have spikes (usually. When imaging, it is a very different story because the camera has far better contrast sensitivity than the naked eye. Diffraction spikes caused by a four-vane spider. Spikes can be removed completely by using a curved-vane spider, though this doesn't actually eliminate diffraction (and reduction of contrast). Only bright stars and planets will typically show diffraction artifacts. I found this to be due in part to greater scattered light in the SkyWatcher and dealt with it by baffling. I moved from an 8" Orion dob to a 12" SkyWatcher and the first thing that struck me was that the diffraction spikes were more intrusive in the 12", leading to poorer planetary contrast. Spikes potentially mean less contrast on planets (every spot on the planet's disc is smeared out into spikes across the surface).
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