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8" SCT eyepieces

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#1 dogeddie

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Posted 18 January 2013 - 01:19 PM

I have an 8" LX 90 and the only eyepieces I have are the 26mm it comes with, a barlow, and a piece of garbage 6mm that Meade gave me free for sins committed against me and my ETX which is not usable. I just do general viewing and would like to get another eyepiece or two without breaking the bank. I am looking for suggestions on models and sizes to help cover a wide variety of options with only a few eyepieces. Thanks for any help!

#2 Starman1

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Posted 18 January 2013 - 02:59 PM

Here is TeleVue's recommendations for the 8" SCT:
http://televue.com/e...lain=TRUE&id=97

My recommendations are for eyepieces that yield 50X, 100X, and 150X and a decent 2X barlow, yielding 200X, and 300X. It's unlikely you'll ever need powers over 300X, and all 3 eyepieces will be usable every time you go out and 95% of all your viewing during an entire year will be without the barlow.

Now, as to what eyepieces? Well, the focal lengths I recommend are: 40mm, 20mm, and 13-14mm.

There are many price ranges of eyepieces that fill the requirements.
I recommend a 2" visual back, 2" star diagonal (keep it short to clear the base on the LX90) and a 2" 40mm eyepiece. Your 20mm (likely to be the most-used focal length) can be 2" or 1.25". And your 13-14mm can be 2" or 1.25".

Sticking with 1.25" eyepieces, there is little reason to exceed 32mm as a low power, because 32mm yields the widest field. 40mm yields the same field, but only lower power. That's why the 40mm 2", which has a MUCH larger field of view and true field in the scope.

With what you have, you have neither the best focal length for deep sky use, nor the widest field, lowest power, eyepiece you need.

Sell the 26 (or keep it), and read Al Nagler's suggestions and you'll know what to do.

#3 REC

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Posted 18 January 2013 - 03:01 PM

Tons of choices out there to fit your budget!

To go wider and lower power, a 32mm Plossl. Next something in the 17-20mm range and then down to 10-12mm for Moon and planets.

Check out the hosts site, Astronomics for a wide range of EP's and also good advise.

Good luck!

Bob

#4 dogeddie

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Posted 18 January 2013 - 04:41 PM

Thanks for the advice!

#5 Lane

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Posted 18 January 2013 - 05:44 PM

If you want to stay with a 1.25" diagonal and 1.25" eyepieces then I would say get:
1. Baader 31mm or 36mm Hyperion for low power
2. Baader 17mm Hyperion or 17mm Orion Status for medium power
3. Explore Scientific 11mm for high power

A 2x barlow would turn the 17 into an 8.5 and the 11 into a 5.5. for really high power viewing

#6 Starman1

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Posted 18 January 2013 - 06:00 PM

If you want to stay with a 1.25" diagonal and 1.25" eyepieces then I would say get:
1. Baader 31mm or 36mm Hyperion for low power

But, when used with the 1.25" adapter, those two eyepieces have horrible vignetting. And, at low power, where vignetting is most visible.
Better to use a 1.25" eyepiece with a largest field stop, like many 32mm Plossls or 24mm wide fields or a couple 35mm with field stops above the barrel.

That 36 would make a great low power eyepiece with a 2" visual back, though.

#7 Lane

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Posted 18 January 2013 - 06:33 PM

Good catch - I did not know that, I have only use the 31mm with the 2" base installed and it was quite a beautiful view in my C8. To good for such an inexpensive eyepiece.

#8 Lane

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Posted 18 January 2013 - 06:36 PM

I switched to a 2" format diagonal early on and never went back, there are just so many more eyepiece options in that format. You could pretty much go all Explore Scientific and be very happy at 2", those are really nice eyepieces.

#9 Brent Campbell

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Posted 18 January 2013 - 07:06 PM

Slight variation:

INITIAL SET:
40 mm explore 68 degree 2"
18 mm explore 80 degree 2"
11 mm explore 80 degree 1.25"
2X barlow

Optional additional eyepieces to be purchased later:
8.8 mm explore 80 degree 1.25 " (get the donut fix)
6.7 mm explore 80 degree 1.25 " (a bit high in mag but it can work)

These eyepieces won't break the bank and when you want to get something else other than the SCT (I like all kinds of telescopes) they will work in whatever as well.

The bottom line, they perform really well, especially the 11 mm!

#10 ibase

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Posted 18 January 2013 - 07:36 PM

..to help cover a wide variety of options..


The 8-24mm zoom (Baader Hyperion/Mark III) works very well with lots of options on my 8" SCT. You can hit optimum magnification suitable for your observing area and seeing conditions with the twist of the power ring plus no EP swapping/fumbling at that. Performance is good too, more so on the slow SCT. Combo it with a 2" longer focal length (in my stall & recommended are the Aspheric 31mm, Panoptic 27mm, Meade SWA 28,34,40mm 5K series, Siebert Observatory 36mm and Paragon 40mm) EP and you're all set. Of course just my 2 cents.

#11 GeneT

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Posted 18 January 2013 - 07:38 PM

Also, slower telescopes, such as F10 SCTs, are much more forgiving. I primarily viewed with an C8 for about 10 years. With this telescope, I used only Celestron eyepieces--lower end in price and quality at the time. They performed quite well in this telescope.

#12 coutleef

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Posted 21 January 2013 - 11:43 AM

my most used EPs on my C8 are a 40 mm, 20 mm and 14 mm and when i swith to lunar and planetAry, i use a lot a 10 and 8mm.

that pretty much goes with Don's suggestions. i must say that a 24mm 68 degrees was also very useful for star clusters.

you do not need to break the bank for EPs with a SCT and 68 degrees EPs are great with not much field curvature.

#13 leviathan

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Posted 22 January 2013 - 06:16 AM

For 8" SCT I mainly use 33mm WO SWAN (2"), 14mm ES82 for deepsky and 6,5mm Meade HD-60 for planetary. I also have a plans to get 5mm EP for 2D, something like 4,5mm HD-60 or 5mm ortho.

#14 mikehager

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Posted 23 January 2013 - 10:53 PM

My favorite 8"SCT setup for planetary and lunar views is with Denkmeyer powerswitch (essentially a selectable barlow) and 19mm Panoptic...LOVE the Panoptic for crisp views of Jupiter, Saturn, or lunar craters.

#15 mitaccio

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Posted 23 January 2013 - 10:57 PM

I too am looking to get an eyepiece for my 8" sct. What's a great 20-24?

#16 Blake Andrews

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Posted 23 January 2013 - 11:44 PM

I'm partial to the 24mm Panoptic.

Cheers!
Blake

#17 turtle86

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Posted 24 January 2013 - 12:06 AM

Also, slower telescopes, such as F10 SCTs, are much more forgiving. I primarily viewed with an C8 for about 10 years. With this telescope, I used only Celestron eyepieces--lower end in price and quality at the time. They performed quite well in this telescope.


By similar token, I use Meade Plossls in my 8" LX200. I have most of the 1.25" eyepieces (they're very affordable) and really enjoy the views in them all. Very big bang for the buck...

#18 troutinco

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Posted 24 January 2013 - 12:13 AM

See my sig for what I use in my cpc800. I use them all at some point or another when viewing, depending on what I am viewing and seeing conditions. I don't like barrlows for some reason...

#19 Starman1

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Posted 24 January 2013 - 02:04 AM

Also, slower telescopes, such as F10 SCTs, are much more forgiving. I primarily viewed with an C8 for about 10 years. With this telescope, I used only Celestron eyepieces--lower end in price and quality at the time. They performed quite well in this telescope.


By similar token, I use Meade Plossls in my 8" LX200. I have most of the 1.25" eyepieces (they're very affordable) and really enjoy the views in them all. Very big bang for the buck...

Add an f/6.3 reducer (if you have an SCT) and a 1.25" 32mm Plossl will give you the largest field possible in an 8" SCT.
If your LX200 is an ACF, you'll need a different focal reducer, like one of the ones from Optec for the ACF.

#20 turtle86

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Posted 24 January 2013 - 09:32 AM

Don, I already have the f/6.3 focal reducer and use it with my 1.25" 32mm Plossl. Really comes in handy for DSO's like the Double Cluster and Andromeda or sweeps through the Summer Milky Way. What's funny is that I wind up getting about the same TFOV (1.2 degrees) using the 8" SCT and 32mm Plossl with 6.3 focal reducer as I do with my 18" Dob and 31mm Nagler with Paracorr II (1.1 degrees).

#21 Darenwh

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Posted 24 January 2013 - 10:30 AM

I like my 30mm ES82 for widest field views. Sure, there is vignetting according to the math but it's not visible to me. Coma and field curvature is there though so maybe going to a 32mm Plossl with focal reducer/corrector would be better. I like to use my ES100 14mm for my mid power eyepiece.






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