Hi Cloudy Nights!
I am new to the hobby, studied sky for several months and recently bought Apertura AD8 scope. Since I had no idea about what eyepieces will work for me I bought Celestron 8mm-24mm Zoom eyepiece. Got quite a good experience understanding about the magnification, contrast etc. I investigated many advices on eyepieces on this forum and came out with the following set of eyepieces to buy in order to get a better experience:
0. $229 I decided to buy Tele Vue 2.5x - 1.25" Powermate to get more options for eyepieces below.
1. $299 Baader 17.5mm Morpheus 76° Eyepiece. [for DSO, I found out that 60° is definitely not enough for DSO, I even could not fit Pleiades.] this will give me 68x and 172x magnification
2. @299 Baader 9mm Morpheus 76° Eyepiece. [for moon-planetary 150x and 333x magnification which covers basically the max useful magnification (42 times aperture).
This leaves me with some gap between 172x and 333x which I am going to fill with Celestron Zoom for now.
1. Why Baader? Because I wanted a very good optics, Tele vue is too expensive for me, Explore Scientific has short eye relief (I wear glasses).
2. My sky is approx 5.5 scale but I have drivable access to 3 and even 2 if I drive 2 hours.
3. I assume I cannot go higher than approx 350x magnification. If I am wrong I might consider 6.5 mm Baader for 185x and 462x (23x and 58 times aperture) for detailed moon and planetary viewing.
4. I assume Baader will give noticeably better view than Celestrin Zoom + Televue Powermate.
5. about 900 bucks for those pieces is my budget for the next year probably. So I would like to be covered for most of the scenarios as a beginner for the next year.
6 I found reviews that the 4.5 mm Morpheus is known to have some edge of field brightening, and the 14 Morpheus is known to have some field curvature. So I did not consider those eyepieces for Baader. I am ready to switch to other decent optics with long eye relief if it makes sense in your opinion.
What do you think? I would appreciate all your advices
I am worried that the quality is not good enough for Zoom eyepiece. Do you think 17.5 won't be enough for DSO? Should go to more 30mm? If so, could you recommend a decent piece?
First you need a good foundation understanding of eyepieces, how they work and the terms used to describe them. Based on reading your notes I am not sure you have that foundation, but forgive me if I am incorrect.
Understanding Telescope Eyepieces- There are recommendations, based on budget,
but the meat of the article is about understanding the considerations and specifications
to know when selecting eyepieces.
Understanding and using a Barlow Lens
Now to specifics
The Apertura AD8 is a very nice scope. I have the AD12.
The AD8 came with a 30 mm /68 degree eyepiece and a 9 mm Plossl eyepiece. Do you still have them? I don't see any mention of them. The 30 mm 68 degree is what you would use to view the Pleiades. That eyepiece will give you 40X and 1.7 degree FOV. The Pleiades is about 1.9 degrees wide. In order to get the entire Pleiades into the FOV you would need the 38 mm/70 degree that I have, or something similar. This has nothing to do with brand. This has to do with magnification and apparent field of view of the eyepiece.
You said that a 60 degree eyepiece is not big enough to vew DSOs. That is incorrect. DSO is not a specific target but designates things other than solar system objects. Some DSOs are very very small and others are very very big. Probably 90% of DSOs are 1 degree or less in width. Most can be seen with Plossl eyepieces with an AFOV of 50 degrees. Of course that would vary by focal length of the eyepiece which would determine its magnification and true field of view. A 32 mm 1.25" Plossl would produce about 1.3 degrees true field of view. Wide enough to contain most DSOs. Naturally as you go up in mag you go down in field of view.
Zooms - I have 3 zoom eyepieces, the Baader Hyperion 8-24 zoom, the Celestron 8-24 zoom and the SV Bony 7-21 Zoom. The Baader zoom is my most used eyepiece. I got the Celestron before I got the Baader and still use the Celestron in my smaller scopes.
Below is a layout of my eyepieces as they would apply to my former Orion XT8, which has the same focal length as your AD8. Very similar scopes. I am not suggesting you buy these eyepieces or that you need this many. I use this eyepiece set for all of my scopes. See this as a planning tool. See what mags are produced and what field of view is achieved with these 70 and 82 degree eyepieces. You can do the calculations for other focal lengths and other AFOVs.
Orion XT8i – 8”/203 mm manual Dob Newtonian, 1200 mm FL F5.9
Resolving power - .6 arc Seconds
AA SWA 70 38 mm 31.5 and 2.2 degrees FOV 2”
Meade 82 20 mm 60X and 1.37 degrees 2”
ES 82 14 mm 86X and .95 degrees
ES 82 11 mm 109X and .75 degrees
ES 82 8.8 mm 136X and .6 degrees
ES 82 6.7 mm 179X and .45 degrees
Meade 82 5.5 mm 218X and .37 degrees
ES 82 4.7 mm 255X and .32 degrees
ES 82 8.8+2XB 272X and .3 degrees
ES 82 6.7+2XB 358X and .22 degrees
Meade 82 5.5+2XB 436X and .18 degrees
Baader Hyperion 8-24 zoom 50X to 150X
Baader Hyperion 8-24+1.5XB 75X to 225X (My most used 1.25” eyepiece in this scope)
Baader Hyperion 8-24+2XB 100X to 300X
The Celestron Zoom would produce the same magnifications with a little narrower true field of view. I bought the Celestron for the XT8. I added the Baader later for its wider field of view and somewhat better optics.
I live on Long Island, East of NYC.
Based on atmospheric conditions, I typically topped out around 180 to 225X most nights. On VERY rare occasions I was able to go to 300X but those were very rare. The Moon will generally take higher magnifications than anything else but the "seeing", the atmospheric turbulence will usually be the limiting factor. I almost never used the 4.7 mm eyepiece in my XT8. Too much mag except for the Moon.
What is SEEING and why it can be bad. This is not a problem with your telescope
I don't know if any of this is useful.
Edited by aeajr, 17 January 2022 - 04:20 PM.