Which eyepiece set?

Cazka (Craig) · #1 14-06-2013, 12:43 PM

Hi, I'm looking to buy a set of eyepieces for my 12" f/5 SkyWatcher Dobsonian telescope.

I bought an Explore Scientific 30mm 82 degree eyepiece about a month back, and was really impressed with the quality of the views in the eyepiece for the price, so I've been looking at more of their eyepieces to complement the 30mm and to replace the 2 Plossls that came with the scope. I want to get a complete set for a complete range of magnifications for viewing all different types of objects. I've come up with these 2 possible sets that seem to meet my needs (all are Explore Scientific):

20mm 100 degree
14mm 100 degree
8.8mm 82 degree
Televue 2x Powermate

24mm 82 degree
18mm 82 degree
14mm 100 degree (heard bad things about the 82 degree version)
4.7mm 82 degree
Televue 2x Powermate

These sets both seem to give me a good range of magnification and exit pupil, and they cost about the same as well, but am really struggling as to which combination to choose. Is there anything I'm missing that the more experienced people here at IIS can see that makes one choice better than the other? I just really want to make sure I get this eyepiece purchase right, since they're so important.

Merlin66 (Ken) · #2 14-06-2013, 01:20 PM

I don't think you'll ever use the 4.7mm on the 12" f5...
The second list (minus the 4.7mm) is pretty complete.

MattT · #3 14-06-2013, 01:33 PM

I'd stick with 2" barrels and get the 20 14 and 9mm ES....and as I have these three can say they are nice eyepieces. Get a 2X 2" barlow. The ES 8.8 82 isn't IME as good as the 9mm. Had the 8.8 too.
If you get the GSO 2X barlow the lens screws off and screwing it onto the eypieces is a 1.5X barlow...just a thought.

Steffen · #4 14-06-2013, 01:51 PM

The 14mm 100˚ and the 18mm 82˚ have essentially the same field of view, I wouldn't put them in the same set.

Cheers
Steffen.

Cazka (Craig) · #5 14-06-2013, 07:14 PM

Quote:

I don't think you'll ever use the 4.7mm on the 12" f5...
The second list (minus the 4.7mm) is pretty complete.

I wasn't entirely sure about the 4.7mm either. It gives just over 300x, which I know is rare, but I thought it might still be worth it for the few nights of good enough seeing.

Quote:

The 14mm 100˚ and the 18mm 82˚ have essentially the same field of view, I wouldn't put them in the same set.

You're right, I'm surprised I didn't pick that up before. Yes, those two are definitely too similar for my taste.

Quote:

If you get the GSO 2X barlow the lens screws off and screwing it onto the eypieces is a 1.5X barlow...just a thought.

Wow, thanks for pointing that little gem out. I didn't know that. I'd only considered the Powermates before because of all the great things I've heard, but that added flexibility of being able to be 1.5x as well sounds very useful.

MattT · #6 14-06-2013, 08:06 PM

The 20mm 100* and your 30mm 82* are also pretty similar in FOV. I'd sell the 30 to get the other 3 100's, unless you need lots of eye relief ??

Steffen · #7 14-06-2013, 08:46 PM

Quote:

Originally Posted by Cazka

I wasn't entirely sure about the 4.7mm either.

You might consider the 6.7mm 82˚ instead, or even the Pentax 8.5mm 60˚.

Cheers
Steffen.

AG Hybrid (Adrian) · #8 15-06-2013, 12:44 PM

9mm, 14mm, and 30mm have worked out as nice spread for my needs. Get a GSO 2x ED barlow and you can unscrew the barlow element and attach it to the 9mm and 14mm for a 1.6x mag boost instead if the full 2x mag boost.

Cazka (Craig) · #9 15-06-2013, 03:12 PM

Quote:

The 20mm 100* and your 30mm 82* are also pretty similar in FOV. I'd sell the 30 to get the other 3 100's, unless you need lots of eye relief ??

Yeah, I saw that when I recalculated all the FOV's again. Still, I think I'm leaning towards getting the 3 100's, and if I find myself using the 20mm over the 30mm, I could sell the 30mm. From what I've seen in used equipment sites around the web, they sell pretty quickly. I don't wear glasses and don't have any issues with eye relief, so that isn't a factor.

GraemeT (Graeme) · #10 17-06-2013, 08:53 PM

Craig,
I've standardised on the ES 82° range with a 24,18,11 and 6.7 and this seems to cover all my current needs. I also kept a GSO 30 and 40 for starhopping but with my new Stellarview finder, they stay in the case.

Cazka (Craig) · #11 19-06-2013, 12:29 PM

Quote:

Craig,
I've standardised on the ES 82° range with a 24,18,11 and 6.7 and this seems to cover all my current needs. I also kept a GSO 30 and 40 for starhopping but with my new Stellarview finder, they stay in the case.

Mmm, I hear what you're saying, but after reading some of the comments here, and scouring the web a bit more, I think I've become committed to the 100 degree line. I don't think I need the 20mm because of how similar it is in terms of FOV to the 30mm I already have.

So I took the plunge and ordered the 9mm and 14mm 100, which ended up being cheaper than a group of 4 82's, and I also took the advice here and bought the GSO 2" 2x Barlow instead of the Powermate. I plan to save up a bit more, and in the future buy the 25mm 100 to finish off the set. It seems like an ideal middle ground between the 20mm and 30mm with some of the benefits of both of those eyepieces (wider FOV than both, higher mag than 30mm, and better exit pupil than the 30mm).