I think CA correction this good can only be explained by the use of an ED glass type with a very high Abbe value close to Fluorite, perhaps Nikon/Hikari’s J-FKH2 (vd 91.36).Īt 10m the Nikon’s resolution measured 1.43” using a USAF 1951 glass slide. There was no detectable longitudinal chromatic aberration around the focused star at 60x and also no significant color fringing at the edges of unfocused objects like tree branches in front or behind best focus. I was also surprised to see that the Nikon did nearly at well at 10m, so unlike most spotters the close focus image is very high quality. The out of focus diffraction patterns were essentially identical on both sides of focus in both scopes at 30m indicating sensibly perfect correction of spherical aberration, not a surprise for the Stowaway, but very rare to see in a spotting scope.
I placed an artificial star at 10m indoors and at about 30m outdoors, in both cases using an Astro-Physics Stowaway as a reference scope. In my experience only the Kowa TSN-883 has equally good correction of longitudinal chromatic aberration. I’ve seen no specimens of more recent Kowa, Zeiss, Swarovski or any other birding scope that equals this one when it comes to freedom from spherical aberration and this specimen showed no sign of any of the other common defects like coma, pinching or astigmatism. The only other single scope that I remember being in the same class was a Kowa TSN-823 about ten years ago. When I did a star-test I was amazed to find this particular sample had probably the best corrections of axial aberrations I’ve seen in any spotting scope. Image quality is superb, with natural colors, very high contrast and sharpness that holds up so well at 60x that it almost seems as if there is no loss at all compared to 20x. It was evident in the first thirty seconds of observing fine details at 60x that this was an unusually good telescope. It works so well that you don’t notice it’s there. The focuser on the new Monarch has a variable speed, faster at close range and slower at longer distances. Eye relief in the new zoom is longer, while the AFOV over the zoom range has remained nearly identical to the old one. The focal length is a little shorter than the old 82mm Fieldscope (about 505mm vs 525mm) and judging from the pattern of reflections returning from the eyepiece lenses the new 20圆0 zoom is not the same design as the old 25-75x. The rest of the optical design appears to be at least somewhat new. One excellent feature that has definitely been retained from the old angled Fieldscopes is the oversized Schmidt prism that allows the light cone from the objective lens to pass through the erecting system without being split by a roof edge as is the case with every other angled scope that uses a Schmidt prism. I had a hunch that it might employ the optics of the old 82ED Fieldscope in a new body combined with new bayonet mount eyepieces. The Nikon Monarch 82ED has been around for over 2 years now, but it doesn’t seem to have made much of an impression in the market or been much reviewed or discussed in optics forums.Ī friend recently bought one and lent it to me to test.
I recently spent a pleasant few hours evaluating a scope that exceeded my expectations in nearly every way.
0 kommentar(er)
