eyepiece or barlow

[Batfink (Peter)]

Hi, just would like some advice from people that know alot more than me.

I have a 8inch 1200mm dob so it's just visual viewing, I also have two televue plossl eyepieces, 32mm and 25mm as well as a Parkes Gold series 15mm, now I was thinking of saving and getting something in the 8-11mm range, probably Televue again, or
option two would be to save and get a Televue barlow
or option three would be to save and save and save and get a Televue Powermate.
I'm just thinking that the Barlow/Powermate would give me more options with what I already have, but I also want the best visual quality I can get.
Thanks for your opinions.

Peter.

[barx1963 (Malcolm)]

If it was me, I would go a TV eyepiece. I have a TV 2x barlow and while it is OK, the views are noticeablely better a crisper in a plain EP of similar power.
By using a barlow you retain the properties of the EP, so if budget is tight, it can be the best alternative.
The TV plossls are the best plossls you can get, so if budget is tight they are worth considering, but even Televue cannot comnpensate for the inherent properties of a short Plossl, poor eyerelief and small exit pupil.
If I was looking at a 10mm EP I would perhaps look at the Delos. It's pricey at $339 from Bintel, but are a joy to use with good eye relief and crisp views.

Malcolm

[barx1963 (Malcolm)]

Of course I hear Explore Scientific are having a sale ATM and their 68degree jobs have a pretty good rep. Never used one myself but certainly worth a look.

Malcolm

[koputai (Jason)]

Peter, the three you already have are great eyepieces. I have the TV Plossls and as Malcolm says, they are fab, if not a little lacking in relief at the shorter lengths. The 11mm is just ok, but the 8mm is very short on eye relief. Combine that with the narrow FOV and I'd not recommend it for Dob use.

The Parks Gold Series are excellent, I have the 25mm and it's as good an eyepiece of any I've owned. You could do worse than going for a 10mm in the same series, but they don't come up very often here in Aus.

A Tak LE would be a good choice too.

Money no object, for Dob use I'd go for the Nagler Type VI 9mm. I have this eyepiece and in my 8 inch f/6 Dob it is the ducks nuts.

Cheers,
Jason.

[janoskiss (Steve H)]

A barlow's good to have no matter what EPs you have. Your nice 15mm Parkes Gold in a good barlow will serve you well for what you're after at the high power end. I'm not a powermate fan (yes, they do work well with no ER issues for long FL EPs, but can't beat a well made 2-element barlow for mid-high power IME). I had many EPs and barlows (and a P'mate) and the EPs come and go but I will always keep my two fave barlows. You can also use inexpensive extension tubes with a barlow to give you a lot of flexibility in magnification.

EP recommendations for your scope: Pentax XF 8.5mm & 12mm - gorgeous EPs and a perfect match for 8" f/6. (I wish I so wish I still had mine!) - and if you combine these with a good 2x barlow you'll have the best of deep sky, planets, and anything else the distant cosmos can throw at you covered.

[ausastronomer (John Bambury)]

Originally Posted by koputai

Money no object, for Dob use I'd go for the Nagler Type VI 9mm. I have this eyepiece and in my 8 inch f/6 Dob it is the ducks nuts.

Cheers,
Jason.

At this focal length money no object the 10mm Pentax XW is a better eyepiece in just about every performance criteria than the 9mm Nagler T6. The only area the Nagler outpoints the 10mm Pentax XW is on size and very slightly on AFOV. The Pentax wins on light throughput, contrast, sharpness, colour fidelity and wins by a mile on comfort

Cheers,
John B

[koputai (Jason)]

I'll bow to your greater experience there John, having not owned a Pentax myself. I'm not getting rid of my Nagler 9mm though!

Cheers,
Jason.

[Fox]

Peter, do you have a budget, if I may ask? The TV Plossls are very nice at the FL's you have, beautiful sharp views and field, but I really think once you start getting to the 8-11mm range, you are much better off with a 65-70 or more deg FOV, and around 20mm ER. It will transform your viewing experience IMHO.

I fully agree with Malcolm and John B, the 10mm Pentax XW, or the 10mm or 12 mm Delos would be magic, if you could afford one at all. That would give you 100x to 120x with arguably the best contrast, sharpness and field that money could buy (albeit I haven't tried a Delos yet). I'd seriously think about the magnification, FOV, and the objects you like looking at, with respect to each eyepiece, before you buy because it is a lot of money to lay out for one prime EP. Then, later down the line, you could add that prime 2x TV barlow or 2.5x TV Powermate to get high power for planets.

For instance, sooner or later I'll replace my 13mm LVW, and I am putting a lot of thought into the myriad of options - Delos (70deg, 20mm ER) vs Ethos (100 deg, less ER), focal length of 13 or 17mm, then 1.25inch or 2inch barrel also comes into the equation, and what will the final framed picture look like in terms of FOV, magnification and background darkness... and will my 27mm Panoptic become more for less redundant? I have no doubt that we all go through the same process when to comes to 'upgrades' for eyepieces...

Fox

[ausastronomer (John Bambury)]

Originally Posted by koputai

I'll bow to your greater experience there John, having not owned a Pentax myself. I'm not getting rid of my Nagler 9mm though!

Cheers,
Jason.

Hi Jason,

Don't get me wrong, the 9mm Nagler T6 is an excellent eyepiece. One of the best at this focal length. Your statement however was pretty sweeping. I would rate the 10mm Pentax XW, 12.5mm Nikon NAV HW (which is also a 10mm eyepiece) (read also a major lot of $$$$$$) and the 10mm DELOS, all ahead of the 9mm Nagler T6, in terms of optical performance criteria.

Cheers,
John B

[Batfink (Peter)]

Thanks everyone, well I didn't want to spend a huge amount, didn't think my size scope was worth it, but can see your point of view about ER and FOV, which is why I thought a good barlow might work, unless my thinking is wrong.
It would take a long while but could stretch for the Nagler Type VI 9mm, I checked out some US sites for the Pentax etc, but was shocked at the shipping charges, min $50-$70.
This is going to take some thought.

[Fox]

Peter, the Delos at $370 AUD across the range, is a good price IMHO considering TV/performance. An alternative may be the Vixen LVW range (although they may still be ~ $300), or cheaper Orion Stratus range (~ $170 at Bintel) which are rated as LVW copies. The latter won't be quite as good at the top tier EP's but I would never scoff at them when budget is a factor. Fox

[koputai (Jason)]

I also take physical size into account. That's why I like Type VI's and Tak LE's. The Delos are big and heavy, as are Ethoi. Other than their size and weight, the Delos appears to be fantastic.

Cheers,
Jason.

[Batfink (Peter)]

Thanks for suggesting the Orion Stratus Fox,
I have just been reading some reviews on it and it might be a good comprimise.

[clive milne]

Explore Scientific 9mm might also be a worthy contender.

Nagler 12mm type 4 is pretty good (nice eye relief and respectable performance even compared to today's offerings)

Pentax XW's nice... but I could never see myself being happy with the fov.

Short focal length plossl? .... I wouldn't recommend this as your best option in a flying fit of incontinent madness irrespective of the label engraved on the side of the barrel. (and fwiw, TV do not make the best plossl available)

Barlow? ... meh... pain in the duodenum. One thing that can be said for choosing this option is that your current collection of plossls will appear to work a bit better, and you'll retain their long eye relief.

[Batfink (Peter)]

Ok after reading everyones replies I saw the merits of good ER and FOV and decided not to get the Televue plossl or barlow.
However I could not justify, to my wife, the price on a top end EP, Nagler, Pentax etc.
So after reading lots of reviews I went with a 8mm Stratus, which I'll be paying off for quite a few weeks.
I had a chance to try it last night and was very pleased, the FOV was great as Saturn tracked across the view, also split some nice double stars and Omega globular filled the view.
It was also easy to look through.
It may not be as good as a Nagler but as long as I don't ever look through one I won't know the difference.

[Fox]

Peter, congratulations and I'm happy to hear you like the EP. I've read that it's only a tad behind the Vixen LVW's, and some rate the LVW's up their with the best. Honestly, I predict that the Orion Stratus line is probably 90-95 % of the performance of the very best TVs and Pentax's, so I think you've chosen really well.

I reckon later on that a mid range 15 to 17mm 70deg FOV will sit nicely between your 8mm and 25/32mm...! Fox.

[Les Kurma]

Which is the best ep then, if you consider optics & Price?

[MattT]

Pentax XW 10mm The best there is... then I really like the Explore Scientific 68 deg series but they stop at 16mm also have a 6.7mm 82deg ES eyepiece and it's also very nice at half the price of the pentax.
Cheers Matt

[Cam (Cam)]

Im no expert but I have an 8" F6 Dob.. My favourite eyepiece at the moment is my explore scientific 14mm 82 degree (wow) I use a 2x barlow and also a TV 2.5mm powermate. The larger FOV is great but it comes down to personal preference mate. Ive seen some people complain about having to move around too much to take in the greater FOV but I love it. Because the powermates have both a negative and a positive doublet your eyepiece ER ect remains basically the same with the magnification, so a little better than a barlow.