Best eyepieces for 10" Bintel Dob?

[mbaddah]

Hi everyone

i am planning on upgrading from my 6" dob to a 10" Bintel Dob soon. I have been doing quite a bit of reading on Tele Vue Radian, Nagler, Pentax eyepieces etc... and how it relates to f-ratios. I find the more I read the more confusing it becomes to coming to a conclusion on what to purchase :(

So i'd like your thoughts and opinions on what you think is best before I splurge $700+ on eyepieces. I don't wear glasses so I don't huge eye relief, but it might be nice to have if I wan't others to view who do wear. Many thanks in advance.

Regards,
Mo.

[rmcpb]

My suggestion would be for you to get the scope and use it "native" for a while. Then you will make some more educated choices based on your experiences and not on ours.

Cheers

[casstony]

The problem is that there are too many good (but expensive) choices. You can cut down the list by sorting out what's important to you. If you want a wider field drop the radians. If you want long eye relief ignore most of the Naglers (the type 4's have longer eye relief). Figuring out your most used magnifications might help reduce the list of candidates too. Armed with a short list you could post a wanted ad and see what turns up.

[mbaddah]

Thanks mate for the help, your right there are too many (expensive) choices, hence the reason for me asking.

Im leaning towards the range of having two general eyepieces, one wide (like a 20-25mm) for general observation, and another say round the 10mm for getting close to say planets. Don't want to go overboard initially, hopefully i can build from there. Cheers.

[casstony]

Well, just to pick two out of the bunch, 17mm type 4 Nagler and 8.5mm Pentax XF ($215 from Frontier Optics).
With people buying the 13mm Ethos recently, you might have a chance of finding a 17 Nagler used to save a few bucks.

[peter_4059]

The other option is to try a few different eyepieces through a 10" dob and decide what you like. Based on my experience I think you are looking at the right focal length range. I started with a 20, 9 and 6mm. Didn't get much use out of the 6 until I put the tube on an EQ6.

Where are you located? There are plenty of people on this forum with 10" GSO dobs.

[davidpretorius]

i have a 10" dob but it is tracking.......My ultimate 3 would be
1. 6mm radian
2. 13mm ethos
3. 24mm panoptic

[mbaddah]

If I didn't have a limited budget hands down i'd purchase the 13mm ethos... to bad its the price of 3 quality eyepieces :(

[wavelandscott]

First, I don't have one and have not yet looked through one...

However, assuming that it is as good as advertised (I believe it is based on people I trust who have used it and reported positively about it) I suspect that it is something that I would keep for a lifetime...so, if I used it every time I viewed in every scope I owned, maybe the price is not so bad...especially if it replaced a few mid-range magnifications the cost per use probably would not be so different than the other eyepieces I do own.

To get back to your question...I'd recommend that you go to the Televue website and read their material on eyepiece selection...

Since I like to stay with 1.25 inch gear,
I'd consider a 24 Panoptic and a 10 mm Pentax XW...but the Nagler 11 mm T6 is not slough either...add in a good barlow (or Powermate) for good measure!

[mbaddah]

Thankyou all for the advice you have given me so far, much appreciated. If i was to summarise:

1. The 24mm panoptic Televue seems to be good choice for wide viewing. (good eye relief, sharpness etc...)

2. The 13mm ethos perhaps is best zoom/fov/all rounder and probably best investment for future as well (good eye relief too). Downfall is ofcourse expensive :(

3. 10mm Pentax XW also has been highly recommended not only here but other threads as well, other than eye relief is there other advantages it has over the Tele Vue Nagler set?

I would have liked to have added in somewhere close to ~10mm Nagler eyepiece as well based on the many comments I've read of "Falling" into the eyepiece from how great the FOV is in Nagler. Is there large price difference between say 9mm/11mm Nagler and 10mm Pentax?

Once again thankyou for all the help.

[GrahamL]

well for $700 and a little more you could grab a 26 mm nagler :evil:
and make do with the 12mm plossl for a while ...you soon forget the initial sticker shock of these pricey ones ..making it much easier to justify buying another.

[CoombellKid]

Especially if the missus leaves you :whistle: you know retail therapy works a
treat :D

regards,CS

[ausastronomer]

At this level the differences between eyepieces are pretty minimal and often subjective based on personal preference. In addition, it can often take very good conditions, a very good telescope and a very skilled observer to detect some of these differences. Fitting most of those criteria, the 10mm Pentax has greater eye relief (not a marginal difference), better light transmission, better contrast, and a cooler more neutral colour tone. On the other hand a Nagler has a slightly larger FOV although the 10mm Pentax XW at 70 deg is perfect for most. I have used just about every premium eyepiece thats currently available new or second hand (I own most of em !!) and I rate the 10mm Pentax XW and the 13mm Ethos as the 2 best general purpose eyepieces currently available to the amateur astronomer.

My choices would be (assuming you don't wear glasses)

1) 26mm Nagler T5. It is a clearly better eyepiece than the 24mm Panoptic, in just about every respect. It's also a lot more money.

2) 13mm ETHOS

3) 10mm Pentax XW

Televue 2X Barlow.

Cheers,
John B

[mbaddah]

Yes I should have made it clear in my first post I don't wear glasses, although I still prefer better eye relief as comfort factor (>15mm).
Nagler 26mm is indeed expensive :( As you said probably for my untrained eye i wouldn't notice much difference...
Would it not be better choice to go for the powermate rather than the barlow? Thankyou.

[ausastronomer]

I don't think so for a couple of reasons. With those eyepieces you only need a 1.25" barlow as the 26mm nag barlowed = 13mm Ethos. Therefore I figure you just barlow the two 1.25" eyepieces. Its not a huge scope so no point adding the weight of a 2" barlow to only barlow 1.25" eyepieces. Moving forward from there, the 1.25" powermate is 2.5X compared to the barlow at 2X. With the 13mm Ethos and the 10mm Pentax XW I think you will get more use out of 2X amplification than you will from 2.5X amplification. In terms of optical performance, the powermate seems to disappear a bit better, but if anything the standard 2X televue barlow is slightly sharper than the powermate. Overall optically they are very close indeed. The barlow is a good bit cheaper for optical equality and more usefullness in your situation IMO.

Cheers,
John B

[mbaddah]

Firstly thankyou all for the advice, I have narrowed it down to few eyepieces.

1) 24mm Panoptic
2) 13mm T6 / 12mm T4 / 10 mm Radian

#2 is my dillemma now :(

Or maybe I should can #1 and #2 and just get a 13mm Ethos :) Argh....