Eyepiece for a 10" Dobsonian Telescope?

[Stargazer_10]

Hi everyone,

I am after a wide field (low power) eyepiece for my 10" Bintel Dobsonian telescope. I currently have a 9mm, a 15mm and a 26mm eyepiece, and I was now thinking for something >30mm. What type of eyepiece (brand etc.) would be suitable?
Thanks for the help!!

[colls (Michael)]

Hi Stargazer, I have a TelVue Nagler 31mm works for me but not cheap.

[raymo]

A fantastic value for money eyepiece is the 2" 30mm 80degree, which
I think Andrews still sell. Mine came with a screw on 1.5x barlow which
I can use with my other 2" eyepieces. There have been several very
positive posts about this eyepiece on IIS recently. I also have the 15mm
version, which gives me 30, 20, 15, and 10mm when using the barlow.
If you have money to burn you can follow Colls advice, and you will
get a great eyepiece; if cost is an important factor, try my suggested
alternative. Whatever you choose to get, I strongly suggest that you get a 2" eyepiece, not 1.25".
raymo

[mental4astro (Alexander)]

Hi Stargazer,

Not knowing your budget, a good inexpensive couple of eyepieces are the GSO Superviews. I started with the 30mm (2") and the 15mm(1.25"). For the money, they are really very good. While I have moved to different eyepieces, I have still kept both of these as they are really very, very easy for novices to use at star parties. 80deg+ eyepieces can be problematic for novices as eye placement can be tricky.

Better quality eyepieces, mid $ wise, there is the Meade series 5000 SWA 34mm (discontinued and only available 2nd hand) and the Explore Scientific 68deg 34mm (essentially the same EP as the Meade 34mm {ES makes Meade eyepieces}). In the 80deg range, there is the Meade & Explore Scientific 82deg 30mm - again essentially the same eyepiece, though the ES is smaller than the Meade (but both are BIG eyepieces). There is also the also discontinued Celestron Axiom LX 31mm, which by all accounts is one ripper eyepiece - if you can find one!

Big $ wise, take your pick. ES 100deg, TV Nagler & Ethos & Delos. There's now a lot of debate about the differences between the Explore Scientific and TV ranges, and if the subjective differences merit the difference in price. Best to judge for yourself with the really big$$$ eyepieces by borrowing from others to try in your scope. Makes for another very good reason to get to a star party of an astro club or an informal gathering, .

The Pentax XW range is also very good. However, they don't all perform equally well in a fast Newtonian. I have the XW 10mm, and it is extremely good.

I have my own reasons for not exceeding an AFOV of 72deg. This too you need to judge for yourself.

But, if you would like a half decent 2" eyepiece to get you started while you decide on where to lay the big bucks, I'd suggest the Superview 30mm. Andrews sells them so does Bintel. The 15mm is also good, and certainly better than the 15mm plossl that came with your scope.

Mental.

[brian nordstrom (As avatar)]

Again , perfect advise Alex , I cant add anything to what you say here .
Brian.

Originally Posted by mental4astro

Hi Stargazer,

Not knowing your budget, a good inexpensive couple of eyepieces are the GSO Superviews. I started with the 30mm (2") and the 15mm(1.25"). For the money, they are really very good. While I have moved to different eyepieces, I have still kept both of these as they are really very, very easy for novices to use at star parties. 80deg+ eyepieces can be problematic for novices as eye placement can be tricky.

Better quality eyepieces, mid $ wise, there is the Meade series 5000 SWA 34mm (discontinued and only available 2nd hand) and the Explore Scientific 68deg 34mm (essentially the same EP as the Meade 34mm {ES makes Meade eyepieces}). In the 80deg range, there is the Meade & Explore Scientific 82deg 30mm - again essentially the same eyepiece, though the ES is smaller than the Meade (but both are BIG eyepieces). There is also the also discontinued Celestron Axiom LX 31mm, which by all accounts is one ripper eyepiece - if you can find one!

Big $ wise, take your pick. ES 100deg, TV Nagler & Ethos & Delos. There's now a lot of debate about the differences between the Explore Scientific and TV ranges, and if the subjective differences merit the difference in price. Best to judge for yourself with the really big$$$ eyepieces by borrowing from others to try in your scope. Makes for another very good reason to get to a star party of an astro club or an informal gathering, .

The Pentax XW range is also very good. However, they don't all perform equally well in a fast Newtonian. I have the XW 10mm, and it is extremely good.

I have my own reasons for not exceeding an AFOV of 72deg. This too you need to judge for yourself.

But, if you would like a half decent 2" eyepiece to get you started while you decide on where to lay the big bucks, I'd suggest the Superview 30mm. Andrews sells them so does Bintel. The 15mm is also good, and certainly better than the 15mm plossl that came with your scope.

Mental.

[astro_nutt]

I can recommend the Bintel 42mm superview and the big barlow(2'/1.25")

[JJDOBBER79 (Jas)]

Hi guys,
I am curious as to the advantages of having 2" eyepieces. I have never used one. I know everyone will tell me to go to a star party to try one but we actually don't have a club anywhere near us. I only have a 6" dob. Are the 2" better suited to larger app? I am mainly interested in galaxy hunting at the moment so would 2" be an advantage for this. Also, my girlfriend is also interested in astronomy but she often has trouble seeing anything in the eyepiece. I think it is an eye placement thing. So, do 2" eyepieces make it easier to see objects???. I see that I can get a 2" superview for $55 so definitely worth the investment if it will improve my/our observing.

[barx1963 (Malcolm)]

Jas
The 2" refers to the width of the barrel. There is no intrinsic value or benefit of a 2" vs a 1.25" barrel except that the 2" ones work better with wider field ones, meaning low power, longer focal length ones.
For example if you buy a Nagler, the 16mm version has a 1.25" barrel while the 17mm one is 2" as at that focal length the 1.25" barrel will restrict the field of view.

Hope that is clear enough.
Malcolm

[raymo]

Hi Stargazer, Everything that Malcolm said is true, but he didn't
mention the fact that the the piece of glass closest to your eye
when using a 2" eyepiece [say 30mm for instance] has a larger
diameter than a 1.25" 30mm has. Add to that that the Superview
eyepieces also have a wider field of view . The end result is that
using a low power 2" eyepiece is like looking through a window;
It can be an immersive experience for want of a better description.
I imagine that Malcolm has been using 2" eyepieces for so long
that he takes them for granted, and has maybe forgotten the wow
factor they have for first time users. If you can get one for $55 I
suggest you grab it.
No criticism intended Malcolm, just adding some information
that I thought might help Stargazer make his choice.
raymo

[barx1963 (Malcolm)]

Fair enough Raymo. The point I was trying to make is that an EP is not better or worse simply because it is a 2" or 1.25" barrel. What matters are the focal length and apparent FOV, as well as less obvious factors such as sharpness across the field, ellimination of false colours etc.
The barrel diameter is a consequence of the focal length and the FOV, and those are the factors taht should be looked at when considering an EP. For example if I was looking at an EP in the 20mm range and want a high end one. I could look at a 20 or 22mm Nagler or a 21mm Ethos. Both have 2" barrels, but the Ethos has a much bigger field of view for virtually the same power.
In the particular example you mention, the Superview has a 68deg AFOV, which requires a 2" barrel, while a 30mm plossl will only have a 50deg AFOV so a 1.25" is enough, and is also cheaper!

Malcolm

[raymo]

I thought that the 2" 30mm [which has 80 deg. FOV] that I got from Andrews quite a while ago was the same EP that is now called a Superview. Since you say that the Superview has only 68 deg. it must be a different product. My 15mm version also has 80 deg.and both are
great value for money.
happy observing raymo

[barx1963 (Malcolm)]

AFAIK the Superviews from GSO that Andrews sell are definitely 68degn and are the same as the rebadged ones that Bintel sell.

Both websites clearly show them as 68's.

Cheers

Malcolm

[JJDOBBER79 (Jas)]

This seems like quite an involved topic. I will have to read more about it. In the meantime, I reckon I will get a 30mm superview and see how I like it. Worth a shot for $55.

[barx1963 (Malcolm)]

Sorry Jas we got a little off topic!
The 30mm Superview is a not bad EP for the money so go for it! It is not quite as high quality as some more expensive ones but is still worth a try to see if you like a wider field.

Malcolm

[AG Hybrid (Adrian)]

Lots of good advice so far. For dipping your toe in a GSO 30mm Super view is not a bad choice due to it being so cheap. But, expect noticeable coma in those outer fields. The superviews were not designed to work well in a fast scope like a GSO 10" - ironically.

The question I ask you however is why you need 30mm eyepiece at all?
Your 26mm gives you ~45x magnification and 30mm gives 39x magnification.

I recommend getting the ES 24mm 82 degree's which will give you a magnification of 49x and a wide field of view of a true field of 1.5 degrees, scrap your 26mm and skip the 30mm. The ES 24mm 82 is priced well. Well made, well corrected for a fast Newtonian like your 10".
Also to consider the exit pupil is a at a good 5.1mm meaning you will still have bright views without brightening the sky back ground too much if there is any light pollution around.
Its also cheaper then the ES/Celestron/Televue 30/31mm and much much lighter.

Also to consider. There's only a small hand full of deep sky objects that wont fit in 1.5 degrees field of view. Put that into perspective of how large 1.5 degrees is. Last month I was looking at the Fornax cluster. I was able to fit 7 maybe even 8 galaxies into my ES 24mm 68 degrees and that only gives me a true field of view of just 1.1 degrees.

[JJDOBBER79 (Jas)]

Thanks for all the great advice on this guys. AG i think you are thinking of Stargazer with the 10" who started the thread. (sorry, I kinda hijacked it). I have a 6" dob. Hoping to upgrade to a 12" in a couple of months. When you say ES you mean explore scientific right? Do you still think that the 24mm will be suitable for a 6"?.

[AG Hybrid (Adrian)]

Originally Posted by JJDOBBER79

Thanks for all the great advice on this guys. AG i think you are thinking of Stargazer with the 10" who started the thread. (sorry, I kinda hijacked it). I have a 6" dob. Hoping to upgrade to a 12" in a couple of months. When you say ES you mean explore scientific right? Do you still think that the 24mm will be suitable for a 6"?.

ES = Explore Scientific.
Whats the focal length of your 6"? The short answer is - probably yes if you have a 2" focuser for the 82 degree variant. More importantly if you are upgrading to a 12" it will work well in your next scope too.

[Stargazer_10]

Thanks a lot for the great advice everyone. I'll have a look around, the televue eyepieces do sound pretty good to me though. Do you suggest buying the eyepiece off the Internet or in a shop?
Thanks again,

Stargazer