As a long-standing amateur astronomer active in photography, one knows that ultimately the aperture, the quality of the optics and atmospheric visual quality determine the quality of high-resolution images.
After three decades of refractor experience the limits of what was feasible were reached for me in relation to the lens aperture (d = 225mm). More resolution could only be attained at acceptable cost with mirror optics. For a solar, lunar and planetary observer with fixed installation a Newtonian system is well suited. Provided, however, that the quality of the optics is associated with high expectations of the resolution. To eliminate any risk in this regard, I decided to buy from the German manufacturer Alluna Optics.  After a short delivery time the ordered 410mm F4.7 Newtonian reflector arrived even weeks before I had started to modify the truss tube of the existing 225mm solar telescope.  A construction phase lasting about a week then sufficed to make the Newton telescope ready for use. 
The mirror saw the light of day in February of 2008. 

I had never seen the moon before at the very high magnification of 400 to 800-fold as bright and especially so sharp. The Orion Nebula clearly showed its colourful appearance at 50 to 200 × magnification. The constellation showed at an 800-fold magnification an ideal diffraction pattern, which testifies to the very high optical precision of the mirror. Other photographic results with a video camera followed the first visual impressions and made my previous pictures of the moon substandard.

In summary, I conclude that the investment in the mirror system 
from Alluna Optics was a very good decision in my career as an amateur astronomer.  Additional results will in future be found on my website(www.unigraph.de).

Harald Paleske 
Langendorf, Deutschland