Art. –Nr. BA-OR-05
Baader Planetarium Genuine Ortho 5mm
Perfect sharpness, to the diffraction limit of our measurement equipment, nearly over the whole field of view. Especially to the edges better than our Plossl- and Super Plossl eyepieces.
x-axis: distance from optical axis in °, y-axis: resolution in arc minutes
Apparent Field of View:
The apparent field of view is about 46°, bigger than expected.
Really good contrast, remarkably better as with our Plossls. It is very close to the Pentay XO 5mm.
Noticeable pincushion distortion. This is surprising for an orthoscopic eyepiece, however, for astronomical observations this is not a big drawback. You will recognize it, if you look on straight lines near to the edge.
Eye relief is very short, as expected. If you do not worry about that, the look into the eyepiece is fine.
The very good quality is described on the main ortho page.
In comparison to the Super Plossl eyepieces on the cheaper side the advantage is better edge sharpness, better contrast and lower sensitivity to reflexes. On the high-end side it is close to the Pentax, but beaten in contrast (just a bit) and abberation. To be fair, the Baader Genuine Ortho will cost you not a third of the Pentax