Eyepieces for 12" Dob

[Tamtarn]

Hi all
We are purchasing a Bintel 12" Dob in approx 2 weeks time. Our current Scope is a Meade ETX125PE with Autostar which we will use to locate Deep Sky Objects to view with the Dob.
Our eyepiece selection at this stage is Meade 26" SP- Meade 15mm SP -Meade 15mm QX- Meade 12.4mm SP- Meade 9mm 5000 Series, and 32mm 2" supplied with the Bintel Dob.
We would like to get a better quality 2" for overall viewing and we feel we need specific FOV and magnification to view Nebula and Galaxies at their most detailed clarity. Either 2" or 1.25".
As this is our first experience with a Dob we need lots of advise on the most suitable eyepieces for our specific needs in the Mid Price Range we can't afford the High End of the market as yet.
Any suggestions from the forum experts would be great.

Barb & David

[ving]

you know, youhave a good range of mid-priced eyepieces already and if they come to focus you should be set. alot of people like to go for wide angle (70-80 degree) eyepieces tho cause dobs generally dont track. I could sugest a 31mm nagler but its not exactly mid-price range... how about a pentax?
anyhow, welcome aboard. people will be coming to your rescue soon :)
:hi:

[xstream]

Hi Barb & David, welcome to IIS.

I was thinking the same as Ving you already have a fairly good range of eyepieces. Maybe a 2x barlow might be a better option?

[Striker]

I would say a http://www.staroptics.com.au/index.php?a=accessories&p=53

But they are a bit expensive but well worth it.

Come on John back me up here.

[Tamtarn]

Thanks Ving we'll check out the Pentax we're thinking about a wide angle but of course they're higher priced also. We apppreciate your info Thanks a million

[Tamtarn]

We're pleased that you think that our range is pretty good I suppose we need to have some Good viewing with the Dob and gain a bit of experience and get the feel of what our priorities may be. Thanks John & Tony for your input

[janoskiss]

Welcome guys. Two members with one login name. I think that's a first. :eyepop:


A low power wide or semi-wide eyepiece at modest cost is a tough ask. 30mm Superview works okay and it's cheap, especially if you buy used. It's not great in an f/5 Dob but you could do worse. Probably a good idea ask Bintel to swap the 32mm RKE that comes with the scope for one of these.


That you can have for not a lot of money (e.g., UO orthos), but if you want a wide field of view (FOV) and good eye relief as well, it will cost you, or you need to trade a bit of performance for comfort. The Orion Stratus or Baader Hyperion eyepieces are very good all-rounders at modest cost. Bintel should be able to get the Stratus EPs for you. The 13mm would be the most useful one to get. The 21mm is a nice low-mid power eyepiece as well, although the LVW version (the original which is a 22mm) is a lot better at that focal length. Check out MyAstroshop for LVWs.

One EP I have to recommend is the 8.5mm Pentax XF --- optically this is just about as good as an eyepiece gets, up there with the 10mm XW for half the cost, and with a slightly narrower but still generous 60-degree FOV. O/S it sells for under $US150 which makes it amazing value. I'd be inclined to recommend the 12mm XF too, but I have not tried it. It might have field curvature issues in the 12" Dob. :shrug: The 8.5mm I own and it is brilliant. Very useful mid-high power focal length for the 12" Dob.

Grab a good barlow for high powers.

[Tamtarn]

Actually I have investigated the Stratus and Baader on the web and thought they seemed to be good value Steve but was unsure of which mag to go for. I wil also check out the other EP'S suggested. Your ifo is a great help.
By the way glad to hear we're a FIRST at something !!
David

[ballaratdragons]

Hi Barb & David,

I have the 12" Dob and I am a Galaxy Hunter and about the best EP I have ever seen 'Galaxies at their most detailed clarity' is the Takahashi 7.5mm ED LE.

I have used one at our last Astro Camp and these EP's bring out exquisite detail on galaxies. I am waiting to read a review about what else they can do.

Apparently they are available in South Australia but I am unable to find out where, but they are easily available from the U.S. at around $140 yanky dollars. The ED lense really helps sharpen up any faint detail.

Steve, Doug and Sue also go under the one username (dugnsuz). :thumbsup:

[circumpolar]

I agree. A good barlow is a must. A 2" barlow with 1.5" adaption gives you a versitile unit. Look in the IIS reviews, there is a review on University Optics 2" barlow. I use the Tele Vue 2" Big Barlow. I find that it corrects almost all the defects in my lesser EP's. Bintel - $335.00.

[mickoking]

I have been doing a lot of galaxy hunting with my 300mm Dob and the 13mm Nagler has become my 'galaxy eyepiece'. I know its a bit pricey but its well worth it for the views. I also use a 20mm superview for nebulae, it is not in the same league as the Nagler but it is much cheaper and produces a 'trasty image. I personally dont use barlows.

hope that helps, cheers Mick :)

[janoskiss]

This is the dealer I was thinking of for the Tak EPs: http://www.astronomy-electronics-centre.com.au/
They have the LE 7.5mm is listed at $295, but better contact them and find out what they really want for them.

The Tak LE sounds very good. I'm not sure if ED glass has anything to do with it. I presumed it's mainly there for planetary viewing, to minimise off-axis false colour. I think you would like the Pentax XF 8.5mm on galaxies too. Similar US price to the Tak LE.

Ah yes, but dugnsuz is usually just Doug. :whistle:

[Tamtarn]

Thanks for your input Mick, info on 20mm for nebula very helpful.
Maybe a Nagler further down the track.

Barb & David

[Tamtarn]

Hi Doug
Have followed up on the website you suggested and the Takahashi will certainly be considered as it sounds great for galaxies.
Thanks a lot
David

[Tamtarn]

Back again Steve
Have checked out Pentax 8.5mm after your recommendation and will add it to our list of choices
Thanks again
David

[iceman]

The Tak LE's are great eyepieces, but I'd recommend getting them second hand from the US (astromart). You'll get them at much cheaper prices than buying brand new.

A Pentax 14mm XW or Nagler 13mm T6 would be a great DSO eyepiece in a 12" dob. Just depends on your funds, as they are quite expensive.

[janoskiss]

After my first serious dark sky session with 10 & 14mm XWs, I'd say the 10mm is the best match to the 12" Dob on DSOs. Seems to bring out the most detail, both on faint fuzzies like galaxies and planetaries and on larger brighter objects like the lagoon (although for framing such a large object you do need a lower power EP). If you get one premium EP, my vote would go to the 10mm XW. Field curvature of the 14mm might also be an issue. But this depends not only on scope and EP but also on observer's eyesight...

Downside of Tak LE's is that they only have a field of view equal to plossls.

[Tamtarn]

Thanks Mike, the Tak LE new is in our price range so it's on our list of choices.
The Pentax XW is a little high in price at this stage. But we're sure that with experience we will invest in one top class eyepieces in the future.
Barb

[janoskiss]

The Pentax XFs would not be, only the XWs. ;)

[Tamtarn]

Thanks a million guys. The info you have all given has been invaluable to us. We appreciate the wealth of experience from everyone. It seems at this stage the Tak LE 7.5 or the Pentax XF 8.5 would be one of our choices, then maybe ? 10-12mm XW Mid Price and maybe ? 20-22mm Mid Price. Including our own EP Range it seems we would cover all bases for Nebulas and Galaxies. Then at a later date we can decide on one favourite Premium EP.
WOW ARE WE GLAD WE JOINED IIS!!!! Thanks again guys
Barb and David

[Starkler]

Regarding buying premium eyepieces.
For dso viewing the eyepiece that will get most use one is the one that will give a 2-2.5mm exit pupil. For an f5 scope this translates to a 10-12.5mm eyepiece

An eyepiece around this range is definately the first one to buy.

[janoskiss]

Do try out some eyepieces before shelling out the big bucks. Each design has its strengths and weaknesses and what is best for you depends to a large extent on your own personal preferences.

[Starkler]

Couldn't agree more !

Some will recommend a nagler 13mm type 6, others will say Pentax XW 10mm.
The user experience with these two is very different and personal prefs will decide which one you want.

[mickoking]

Another thing

When viewing nebulae a good filter can make a HUGE difference. I keep a OIII filter almost permanantly attached to one of my 20mm eyepieces. The contrast/visual gain on some objects like the Eta Carinae Neb (NGC 3372) and the Tarantula Neb (NGC 2070) among others is phenomenal, particuly in a 300mm 'scope.

Highly recommended :thumbsup:

[Tamtarn]

Hi Mick
We have a Astronomik UHC filter we find works well on our Meade ETX 125. ( 5" )
Do you think this will also be suitable on our 12" Dob ?
Barb & David

[mickoking]

Better :D

[janoskiss]

what's better Micko? The UHC better than the OIII? I've been considering buying an OIII filter but only if it does something visually different to a general purpose narrow band nebula filter. :confuse3:

[mickoking]

Sorry for that. What I ment to say is the UHC filter will work better on the larger 'scope.

With regards to the OIII filter It has higher contrast than the UHC filter, Borrow one and check it out if you can, I promise you it will be worth it :)

[Tamtarn]

Steve you will find info on the UHC at http://astronomik.com/english/eng_uhc.html Everone seems to have their own preferences on Nebula filters. It gets down to personal choice.

Barb

[Tamtarn]

Sorry forgot to add we chose the UHC to use with our 5" scope at the time

Barb

[ausastronomer]

Hi all,

I am a bit late to this thread.

If you only plan to buy 1 filter for DSO work, the UHC is the best one to get. The OIII and UHC assist to a similar degree on a lot of targets, but there are some targets where one filter will work better than the other. The UHC offers "some" improvement on a larger number of targets than the OIII. In addition the UHC does not dim the background field stars quite as much as the OIII. Owning a 12" scope, if its within your budget you will get some benefit owning both a UHC and an OIII filter, but you will use the UHC more often. In smaller scopes (less than 8" aperture) the UHC will see a lot more use than the OIII. I own both the Astronomiks UHC and OIII as well as the DGM Optics Narrow Pass Band (NPB). The Astronomiks filters are the best available IMO. The DGM is the best value for money.

CS-John B

[square_peg114GT]

Ths is the most comprehensive comparison of nebula/light-pollution-reduction filters that I've seen.



Filter Performance Comparisons for Some Common Nebulae (http://www.cloudynights.com/item.php?item_id=387)

[Nightshift]

Hey, you guys will have exactly what I have, I have an ETX90 with the full complment of 9 Meade Plossl EP. When I bought the GSO 12" (rebadged as Bintel) it came with some pretty ordinary EP, they dont focus well to the edges but OK as beginner EP, the Meade plossl's all focus perfectly in the 12" and I dont recommend changing them for anything less than expensive EP's like the Televue etc. you already have the best "mid" priced EP.s.

Save your money and buy yourself a green laser, remove that crappy old finderscope on the ETX and retro fit it with the laser, then the goto on the ETX combined with the green laser works a treat for finding objects with the DOB. Best money you could spend for the moment.

Cheers, Dennis.

[Tamtarn]

Hi John

Thanks for your input on filters.
We are looking forward to using the UHC on the Dob ( Dob pick up day tomorrow ) Maybe a OIII further down the track.

Our next buy will probably be a 10XW. and then possibly a Stratus 21mm or LVW 22mm if funds permit.
Also int in a green laser to be mounted on to our ETX125 so we can use it as a tracking scope for the Dob. The ETX already has a Red Dot finder.

Thanks Again
David

[Tamtarn]

Hi Dennis

We have had thoughts on a laser for the Dob and using the Red Dot finder on the ETX, But your suggestion would probably be better.
Can advise details of your green laser setup with bracket and what power of the laser you use.
Where did you buy it and what brand ?

Thanks
David

[ausastronomer]

David/Barb

Sorry I missed this post. I have been really busy and haven't visited the forum much recently. I only picked it up when I was following up on your post about taking the plunge and buying a premium eyepiece.

I hope you decided to buy the 10mm Pentax XW? It is the best 1.25" eyepiece I have ever used !!!! and I have used a fair few. It is also perfectly suited for medium power DSO work in your 12"/F5 as it creates a 2mm exit pupil @ about 150X which is ideal for that purpose.



At this focal length the 21mm Denkmeier is the best 1.25" eyepiece I have used. I own the 20mm Pentax XW and have also used the 22mm Vixen LVW, 21mm Orion Stratus, 19mm, 22mm and 24mm TV Panoptics. Of all these I like the 21mm Denkmeier, although they are all very good.

http://www.buytelescopes.com/product.asp?pid=10465

The Denkmeier eyepieces only come in 14mm and 21mm focal length and are designed for use in the Denkmeier Binoviewer but work very well in fast scopes and used singly. They are about $US 260 or $AUS 400 each.

CS-John B

[Tamtarn]

Thanks again for your info John. We will certainly consider the Denkmeier in the 21mm range when funds permit.

We appreciate your opinion on this subject.

Barb & David