Close-ups taken with a reversed 28 mm Nikon Series E lens. Optically, you can expect every lens flaw imaginable: field curvature, corner softness, spherical aberration, CA, what else is there? Of course no aperture control, so expect long exposures on a tripod if you plan on stopping down to f/8 or more. However, I find the results strangely pleasing, or at least amusing for the time being, and will play a bit more before I destroy the lens coatings for UV photography.
The actual image ratio is approximately 2.5:1, with a working distance of about 5 cm (2 inches). I think the field depth wide open is about 0.5 mm or less.