I owned a scope like this for 11 years and came to the conclusion the following magnifications were useful:
50X, 100X, 150X, 200X, and 250X. Very rarely higher.
The eyepiece focal lengths are:
40mm, 20mm, 13-14mm, 10mm, 8mm
It will depend on what you want for largest true field as to whether you convert to a 2" visual back, but because of the slip clutch altitude axis and the lack of clearance with the base, i don't recommend it on this scope.
That would confine your maximum true field to 0.76 degrees, and that's just not wide enough.
So I advise adding the Celestron f/6.3 focal reducer to the scope. That would mean your all-1.25" eyepiece selection would become:
24mm 68 degree eyepiece (1.21 degrees!)
13-14mm widefield or ultrawide field.
9mm wide to ultrawide field
6-7mm wide to ultrawide field
5mm wide to ultrawide field.
The reducer/corrector flattens the field and improves star images across the entire field.
It allows a widest-field to be accomplished with smaller and less expensive 1.25" eyepieces.
It doesn't overweight the back of the scope and require a counterweight.
It's removable for use at f/10 if desired--2 scopes in one!
Now a judicious application of a good barlow would reduce the number of eyepieces needed. The 13 to 14mm could become a 6.5-7mm if barlowed, and a 9 to 10mm could become a 4.5-5mm if barlowed.
That might give you a bigger budget for the 3 eyepieces you then need.
I have my favorites, but because I am in the business, I won't recommend specific brands or models.
I think you'll find when you need a wide field, you'll go down to the 24x68 and when you want to do general observing you'll jump to the 13. having an eyepiece for 75X probably isn't necessary.
Don Pensack
Los Angeles
Quote:
Originally Posted by Solanum
I just bought a Nexstar 8SE from another forum member and I'm thinking about eyepieces. The ones I have filled the range I liked for my dob, but this scope has a 2032 mm focal length, 203 mm aperture and is F10, so they have very different magnification.
I used to find 50x was handy for locating stuff, 80-100x best for general viewing and 150-200x good for detailed viewing in good seeing. My better eyepieces are now in the 150-350x range....
Would adding a 40 mm (approx 50x) and 30 or 25 mm (approx 70x-80x) be sensible for this scope, or have I made a mistake somewhere? I guess ideally, I'd want 50x, 75x and 100x, though I have the latter.
I don't see a lot of 1.25" eyepieces at the 30-40 mm size. I guess my budget would be looking at something of the level of a second hand Vixen NLV (SLV is it now?) type of thing. Any suggestions?
My 6mm didn't get a lot of use before, I think it will get very little use now, should I just sell it?
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