3D anaglyph format: use red/cyan glasses to view.
The Vacuum Tower Telescope at the National Solar Observatory on Sacramento Peak (USA) is capable of amazing resolution.
A sunspot is cooler than the rest of the solar surface, which is why it looks dark. It is also depressed (as can be seen when a sunspot is viewed near the edge of the solar disc.) The surrounding solar surface has small "bumps" on it from convecting hot solar material. Their direction is distorted in the penumbra of a sun-spot by intense magnetic fields.
These features have been shown here by image processing the original picture (featured in Astronomy Picture of the Day). It is NOT true 3D but the author's imagination of how it might look in 3 dimensions.
Whole sun in 3d anaglyph single wavelength
3D Sun in 2 wavelengths
