Excellent sharpness all across the field. I was astounded by views with the 13mm Type 6 through my 12 f/10. Riveting detail on the Lunar surface with unmatched sharpness. Outperforms similar f.l. eyepieces of other brands that I have used. Highly recommended.
I am extremely pleased with the Nagler 13mm Type 6 - it is one of a few eyepieces that I call optically perfect. Unbelievably crisp views, out to the very edge. Lunar detail is riveting through this eyepiece and my 12 SCT. I strongly recommend adding this piece to your collection.