I haven’t done a star test and don’t have a high enough magnification e/p for the test according to the article I read in Sky at Night (
How to star test a telescope). Sounds like a good idea though to test the optical quality of the scope. In any case I like the idea shared of trying the Baader Morpheus 14mm e/p with its ample eye relief and ultra wide AFOV. The 9mm at 43x might be at the limit of the scope‘s ability if astro viewing is involved according to what was shared by Swedpat. As the primary use for the scope is birding, the optical limitations might be less noticeable in that kind of viewing. Anyway, the only advice I haven't heard is the value of a zoom such as the Pentax 8-24 mentioned above. I love the idea of a quality fixed eyepiece with wide field of view, but just don’t know how much I would be giving up with the need to switch lenses or not be able to just zoom. I do fine actually with the fixed lens binoculars. Maybe a single magnification scope with occasional swapping out for a higher magnification lens is a good solution. Opinions based on experience anyone?
Short answer:
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Zoom for general use, fixed eyepiece for special cases.
I can recommend the 23mm aspheric or the 18mm UFF for your scope. The 23mm is unbeatable at its price point (US$10) and is an easy choice, the 18mm costs more (US$90 on AliExpress) but is very high quality.
Get the 23mm aspheric first and see whether you like a fixed power scope, if you do then you can consider spending more for better eyepieces like the UFF, Pentax XF, Pentax XW etc.
Long answer:
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I wear eyeglasses and use a 80mm Svbony SV406P, f=432mm. It comes with a 7.2mm-21.6mm zoom (20-60x, 42-65 degrees FOV). It takes 1.25" astronomical eyepieces natively. My additional eyepieces:
23mm aspheric (62 deg, 57 measured)
18mm UFF (65 deg)
10mm UFF (60 deg)
9mm Svbony redline (70 deg)
4mm TMB clone (58 deg)
General Use:
I use the zoom for most of my birding (perched/walking birds 10-30m away). The ability to locate at low power, then view at mid/high power is a huge convenience. 60x is usable in bright light but usually the bird is already nicely framed around 30-40x. I use 60x more often for insects eg dragonflies.
Special Cases:
For birds in flight 50-100m up in the sky, the 23mm aspheric (19x) and 18mm UFF (24x) provide a wider FOV to find the bird, and 19/24x is fine for viewing. At higher power, the birds move too fast in the field of view for me to track anyway. For flying birds at close range, I use my 8x42 binoculars instead.
Other Notes:
I found the 10mm UFF redundant, the zoom covers the same magnification and FOV. The 9mm is wider than the zoom and very sharp, but suffers from SAEP/kidney beaning in the day, so I reserve it for night use where it gives nice views. The 4mm gives 108x, I have gotten amazing views of dragonflies from 6m away (minimum focus distance) and for larger birds further away eg storks I get close up views of the head/eyes etc. However, my tripod is not nearly stable enough, focusing at 108x causes vibrations so patience is needed. The view is also dimmer, so only good in bright light.
Conclusion:
When birding, 99% of the time I stick with the zoom. I bring the 23mm and 18mm but seldom use them. At night I bring everything out, and sometimes I stick with the zoom for convenience, other times I switch to the 18mm and 9mm and enjoy the views. For the 4mm, the stars/planets drift quite fast in the field of view, so it is not as fun to use.