Eyepiece upgrade for 250 goto flextube

[Bumfluff]

Hi all,

I’m looking for some advice upgrading my eyepieces. (it's my birthday at the end of the month )

I have a 250 goto flextube and use the supplied 10mm and 25mm, I also have a Baader 31mm aspheric which is great for wide views. I also have the Baader 2.25 barlow.

Until recently I also had a Baader mk3 zoom eyepiece (out of warranty) which has now packed up. I’ve managed to repair it but now it’s just an alignment piece due to some bits stuck on the inside lenses. So I’m in the market to replace/upgrade with fixed eyepiece(s).

Bit of a minefield trying to decide on what would be most suitable. Firstly I looked at the Baader Classic Ortho range, then the Hyperion range due to a wider FOV. Now I’m looking at Explore Scientific 82 deg range.

I am looking for something round the 11mm size for general use with the intention to use the 2.25 barlow for higher mag usage (which offers 1200/11 = 110mag and 110*2.25 = 250mag)

My budget is around the £150 mark and if possible maybe get 2 eyepieces ( possibly a 17-18mm in the same range)

Any advice would be most welcome!

Thanks in advance

Greg

[Eastridge]

Most will say to steer clear of the Hyperion's when you have a fast scope f4.7 like we do, due to edge issues. I use mine for planets only so it's less of an issue but for general use would steer clear.

I don't recall what the ES 82' s are like with fast scope someone will be along later who does. People do mention the Celestron E-cel LX's and BST's as being good in fast scopes, but they don't have the wide FOV.

[Damo636]

With your budget of £150, the 11mm ES 82° would be a fine choice. A used 11mm t6 Nagler would also be within reach! I'd avoid the fixed fl Hyperions with your scope.

[Stargazer_00]

I use the ES 82 degree range and use the same scope, albeit the solid tube. The optics are the same.

I've posted a review of sorts in the member eqiupment reviews which you might benefit from reading

[Qualia]

Bumfluff , many astronomers - myself included - follow quite a predictable path when it comes to buying EPs and to a lesser extent Barlows. For whatever the reason, sound or not, we start out buying our upgrades new and on the 'cheaper' side of things, but soon arrives a day when we want to seriously upgrade our kit, perhaps we've seen how a premium EP works, but now we find ourselves in a situation where we have one quality EP and a case full of relatively cheap EPs that on the secondhand market are going to lose use a fair bit of money.

So, I'd say save a little extra and go premium. These type of eyepieces are never a waste of money, especially if you buy them already used. These EPs might even become 'lifers', so you never have to change again or you could always re-sell them without losing much or any money, especially if you buy them already secondhand. It is worth bearing in mind that quite often a decent Panoptic, Nagler, Radian, for example, will crop up on the secondhand market between £100 to £200, especially as there appears to be a growing interest in 100º EPs. You buy one of these, you use it and if you don't like it you sell it on (assuming you take good care of it) for exactly the same price, whereas if you buy a brand new ES 82º, for example, although its quality is probably almost-almost premium, if you decide to sell it, I imagine you will automatically be throwing away about £50.

If you didn't want to go this route, I'd advise one to buy secondhand Televue Plossls (TVP) and Baader Genuine Orthos (BGO) which offer sharp, contrasty and excellent edge performance. These are superbly executed eyepieces in the superlative and the only reason they are not quite premium is because they lack the important and expensive features of premium EPs, viz. wide-fields and better eye-relief. Personally, I'd buy BGOs less than 12mm and TVPs 11mm and longer, for eye-relief in short focal length Plossls can be tight. Again, you can pick up a TVP for around £50 to £65 secondhand and if you avoid the current madness craze in the UK, a BGO for around the same price and if you ever decide to sell them on, you'll receive the same money. As a general rule of thumb, buying quality you only cry once and by buying the best optics you can afford, they are more than likely going to stay with you.

If we have a look at the numbers solely in terms of magnification for now, we have with the 2.25 Barlow:

31mm: 38x, 87x

25mm: 48x, 108x.

10mm: 120x. 270x

In my eyes, apart from going a tad higher for planetary, Lunar and globular work, that is quite a decent spread. So, I'd be practicing as much as possible to see if I really wanted to upgrade on any of these magnifications. I'd start on focussing on something which offered about half your aperture in magnification, something like 120x to 125x which would also give a 2mm exit pupil. That is, for example, covered by your 10mm and 25mm barlowed. If you feel the image quality is wanting, check out a selection of choices around this focal length. I'd also be thinking of a magnification around 90x, which again is covered by your 31mm barlowed. And again, with close attention, if you feel the image is wanting, check out a selection of choices around this focal length. Other than that, I'd also be wanting something which offered about 140x to 160x for a little Jupiter and Saturn work and perhaps on another occassion, something which offered about 160x to 200x on those nights of exceptional seeing and for general close inspection of the Moon.

Hope this has given some food for thought

[Bumfluff]

Hi again,

That's a great review of this range of eyepieces Stargazing00

Thanks for your replies. You have pretty much echoed my own thoughts from researching what would be most suitable. I have decided to omit the Baaders from my shortlist as I have read the discontinued BGO eyepieces seem to outperform the newer BCO eyepieces. Also as stated above the Hyperions seem to suffer at the edges at F4.7 so they're out as well.

Which leaves the Explore Scientific eyepieces from new and perhaps a Televue second hand.

I am considering an 11mm Explore Scientific 82 degree eyepiece, or possibly the 14mm.

I will be keeping an eye out on ABS for second hand Televue too for higher magnification viewing, possibly the Nagler 3-6 zoom which will be the subject of my next search to see how well it peforms with my scope.

regards

Greg

[John]

Thanks for your replies. You have pretty much echoed my own thoughts from researching what would be most suitable. I have decided to omit the Baaders from my shortlist as I have read the discontinued BGO eyepieces seem to outperform the newer BCO eyepieces. Also as stated above the Hyperions seem to suffer at the edges at F4.7 so they're out as well.

Eyepieces with wider field of view do make sense with a manually driven scope like a dobsonian.

Don't lump the Baader orthos (BGO's and BCO's) together with the Hyperions though. They are very different products in my opinon. Both types of Baaser ortho, in purely optical terms and within the confines of the design constraints, outperform all 82 degree FoV eyepieces I've used, including Naglers. The difference between the BGO's and BCO's was very slight when I tested them. The 18mm BCO seems to have slightly better light transmission than the BGO 18mm as it happens.

In terms of pure sharpness, resolution, contrast and light scatter control, the Baader orthoscopics are as good as anything out there until you hit the expensive rarities like the Zeiss Ortho's, Pentax XO's and TMB Supermoncentrics.

But, as I said at the beginning of this post, wide and ultra wide eyepieces do make using dobsonians a bit easier especially at high magnifications.

I guess you know this but, just in case, the Nagler 3-6 zoom (excellent eyepiece) has a 50 degree field of view across it's range. Some folks see the Nagler name and assume 82 degrees

[alan potts]

The 11mm Ex Sc is said to be the pick of the litter. In my opinion you could do a great deal worse than buy one of these. Also as Damo 363 mentioned the 11mm Nagler is also within your grasp and they don't get any better than that.

Alan.

[Stargazer_00]

I am considering an 11mm Explore Scientific 82 degree eyepiece, or possibly the 14mm.

I'm yet to run the new 11mm. The 'old' style one performs quite well but I excluded it from the review because it was pointless, in that you cant actively buy the eyepiece new anymore.

I made my thoughts on the 14mm pretty clear I'd hope especially in this scope I found it excelled.

[JamesF]

I can confirm that the BGOs work outstandingly well with my 250P optics, lack of field of view being the only minor niggle from my point of view though others may well not get on with the lack of eye relief. FLO have been waiting for some time for delivery of some new ortho eyepieces that may well be as good as or very close to the BGOs. I believe John is going to review them when they arrive.

That said, I do prefer the Naglers and Panoptics that I have because of the wider field of view.

James

[Qualia]

My budget is around the £150 mark

There's a nice - by all accounts - Pentax XF 12mm on ABS going for £90. If I lived in the UK, I'd probably buy it. From the reviews I've read on Cloudy Nights and this review, they appear comparable to Televue Radians and one can be sure that anything coming from Pentax is going to be top quality stuff. You might want to read this as well from Michael here at SGL.

[Bumfluff]

Morning all Thanks again for all your replies. You have given me much to consider.

I have been thinking more about whether or not having an 82 deg is the best way to spend my money as I have a goto so therefore I can track the object.

After reading a few more reviews on the BCO range. I'm now thinking these could be a better use of my money?

regards

Greg.

[Bumfluff]

Hi all,

Well, after slowing tying myself up in knots trying to decide which eyepiece to get for my birthday. I have just ordered an Explore Scientific 11mm 82 deg.

Apologies in adavance for the cloud cover over the west midlands in 3-5 days time.

Thanks again for all your help

Greg

[Damo636]

Good choice Greg!

[Stargazer_00]

Good choice I think Let us know how you get on with it, I suspect it'll be very good for you.

[Bumfluff]

Hi all, Had my Explore Scientific 11mm 82 deg eyepiece delivered yesterday from optical-systems.com, took a 5 working days from dispatch to delivery. WOW... an impressive box these come in, I was expecting a jiffy bag and a tube like the stock plossls (will post a couple of images once I'm home from work). First impressions are good, it feels sturdy and well made

As usual with new kit it came supplied with cloud cover, although it's looking up for Friday/Saturday for first light!!

Will update here for anyone interested!

Greg

[Stargazer_00]

Looking forward to it, Greg.

[Jules Tohpipi]

Very interested to hear how you like it.