To give the Skywatcher UWA-58 5mm a few challenges I steered away from its description as a Planetary eyepiece to check out some multiple star systems.
Telescope used was a Skywatcher Skyliner 300mm (12″) Dobsonian, which gave 300x magnification.
First target was the famous “double double” in Lyra. The very first impression was the wide field of view. In fact it was much wider than my TMB 10mm eyepiece that I used to centre it. The separations of 2.6″ and 2.3″ (arc seconds) were an easy target , with clear dark space seen between them. The rubber eye cup was excellent, and made the observations very comfortable. An added bonus were the two 13th and 15th magnitude stars that are positioned between the two double stars. The extra light gathering of the 12″ Dobsonian made these very easy to see, without averted vision needed. Contrast was superb from an eyepiece that costs less than £50
Next target was Iota Trianguli. Often referred to as the second best colouful double star behind Alberio. Although the view was great at 300x with the 5mm, I would have best choosing something with less power for a better view.
Last but my no means least, a tough challenge. Iota Cassiopeiae is a triple star system with magnitudes of 4.65, 6.9 and 8.7. Separations of 7.4″ and 2.7″. The wider star of Mag 8.7 is easy to see. The tricky part is the two brighter stars. A combination of glare from both bright stars and the tight separation of only 2.7″ makes this very difficult (on paper). The Skywatcher UWA 5mm did not let me down. The separation was clearly seen, making this a lovely triple star system that should be on all dedicated double star observers lists
The superb Skywatcher 1.25″ UWA-58 5mm eyepiece can be purchased from Northern Optics . Summing up. Just because this is called a Planetary eyepiece, do not think it is just for Planets. Its a great double star splitter.