TS Super Ploessl 4mm
Not convincing, especially in the center. Even at 4mm there are better ones. Our measurement system is diffraction limited at this focal length to about 1.4 arc minutes.
x-axis: distance from optical axis in °, y-axis: resolution in arc minutes
Apparent Field of View:
The apparent field of view is approx. 48°
Just good contrast.
Very slight cushion distortion.
Very short eye relief because of the short focal length. Viewing the complete field of view is not possible without looking into the eyepiece under different angles.
Nice. You do not need more to use it for a long time.
Not too bad for a 4mm eyepiece – but I have seen better ones.