Thank you, very informative...it can be hard navigating the forums to find this info and making sure it's up to date. I still have research to do on barlows, but appreciate that input as I haven't even looked into them to get better magnification.
I see your recommendations and will be looking into those, but if I had to pick the XW20 or XW16.5 for what I want to see which should I go with? I'm wanting to keep my collection minimal...maybe 3-5 eyepieces. I have the 25mm plossl and 10mm XW already so the 16.5 would make sense right?
The 16.5mm 85° Pentax is $479.95 and 2" diameter.
TeleVue's 16mm 82° is $369 and 1.25" and renowned for its incredible sharpness. It has only 10mm or eye relief, though, probably just *barely* longer than your eyelashes, so definitely not glasses-compatible.
At 127x, it's beginning to get to be an excellent spread from a 25mm (81x - 127x = 46x). The next jump, keeping the same spread would be to a 11-12mm focal length.
If the 10mm is the bedrock, the next longer focal length should be 14mm, then 20mm (you can see why Pentax used that spread).
Perhaps you should be looking into 2" visual backs and 2" diagonals. Then you could get some truly wide fields at low power.
One other option for the 8" SCT: add the f/6.3 focal reducer/field flattener to convert your scope to f/6.3 (1280mm focal length).
Then you could have the big fields with 1.25" eyepieces and skip the expense of 2" eyepieces, 2" diagonals, 2" visual backs.
A 32mm Plössl or 24mm 65-68° eyepiece could yield a 1.21° true field, where now your 25mm yields only 0.61°!
A nice set of 1.25" eyepieces at f/6.3 could include: 26mm, 13mm, 8.5mm, 6.5mm, 5mm--all small and light eyepieces.
You could even go with all-Pentax: 14mm, 10mm, 7mm, 5mm and add an Explore Scientific 26mm 62° for maximum field or an APM 24mm Ultra Flat Field 24mm 65° or an ES 24mm 68°.
Or, a set of Baader Morpheus at 14mm (measured at 13.9mm), 9mm (measured at 8.9mm), 6.5mm (measured at 6.7mm), 4.5mm (measured at 4.8mm) and add the 24mm wide field for low power/widest field.
The focal reducer costs about the same as a moderately-priced eyepiece. And, it can easily be removed to use the scope at f/10.
I think you'll get used to the wider true fields, though, and better edge correction.
Edited by Starman1, 19 September 2023 - 06:17 PM.