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pete_81

Eyepiece queries, f/4.8

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Posted (edited)

Hi all,
First post here but been member for a few years just browsing.
Looking for some help and advice on eyepieces.

I've had an Orion Optics (UK) Europa 250 (f=1200, f/4.8) reflector for many years and keep going through phases of getting it out and being impressed by what I see through it for all types of clusters, DSOs and planetary. I've upgraded it a few times to have a 2" Crayford (with 1.25" adapter) from the supplied Rack & Pinion focuser, added centre marker to primary, cooling fan to back of primary, amongst other mods to both scope and tripod (which isn't really stable enough for such a large scope, but that's not for now).

Looking at upgrading the supplied eyepieces, which are initially a Series500 Plossl and 25mm Plossl, alongside a x2 Barlow.
I've found several websites that detail the Series 500 (eg https://www.cloudynights.com/topic/547181-series-500-plossls and other links within this page), suggesting that they're not bad eyepieces, although from reading around, they (like most) probably struggle at off-axis with the fast scope. The 25mm, I've no idea about. Supplied with the scope, I doubt it's anything as fancy as a TeleVue Plossl, but the green writing and OO-UK now selling these may suggest it could well be a TV. Can anyone suggest yay or nay to this looking at the attached photos (there's no other markings on the barrels so no AFoV or manufacturer details)?
Also, no other markings on the barlow, so wondering on manufacturer if anyone knows, or should it just be left to gather dust rather than possibly ruin observations?!

So, onto the main topic - new EP(s)!
Looking around, (eg older posts at https://stargazerslounge.com/topic/189230-wide-field-eyepiece-thats-suitable-for-f47-newtonian or https://stargazerslounge.com/topic/280181-what-eyepieces-for-f4-scope/) it's obvious that I need to spend significantly to get something that really lets the scope perform. But that's not where I'm at just now, rather looking as upgrade/addition at this point (not looking to buy the TV Delos/Ethios until the kids have left the nest?!). With the long focal length of the scope, I'm thinking about longer focal length (30-40mm) EP that will give a slightly larger TFOV (mag of 30-40x), which tends be better suited to DSOs. Also having less mag would keep objects closer to centre of view, so suffer less from aberations or is that wasting the EP? Perhaps a larger AFOV may be better with a shorter focal length (eg 60deg AFoV on a 20mm still gives TFOV of ~1deg in sky, so M42/M57 easily observable here).

So, choices...
I've seen the Baader Hyperions (and the Zoom MK IV), but think I've seen John Huntley's review against the Vixen LVW on https://www.firstlightoptics.com/blog/vixen-lvw-vs-baader-hyperion-review.html. Although as an upgrade point, are these still contenders or do a cheaper alternative before looking to the better Vixen/TV/Pentax/etc.
Are Plossl's still good EPs?! Or is the Plossl just a good EP in general across the centre, then suffers around edges esp in faster scopes, hence need to go for different designs? The Meade 4000 (on listings like https://www.rothervalleyoptics.co.uk/meade-series-4000-super-plossl-eyepieces.html) say they're good for f/4, but is this just sales jargan?! If they're still good, what are the feelings towards the following EPs:

Meade 4000 SP
Celestron Omni
Vixen NPL
TeleVue Plossl

Obviously the TeleVue Plossl is similar budget wise to the Hyperion, Meade 5000 and Vixen SLV, so if the limit on the Plossl is off-axis and tigher FoVs, is the Hyperion/SLV a better choice? Remembering that I'm looking to take steps in upgrading and not just splash to the best of the best (and I'm city based so do see my fill of stray light, but the scope +25Plossl easily picks out Mag 8 stars from the back garden), can I have some recommendations on both lens choice and focal length (whether to go for a longer 32/40mm or fill in gap with 15-20mm range, eg Hyperion 17) on what to get next. Also if anyone knows if the 25Plossl is TV or not would be good as I then don't need to think about upgrading this one for some time.
As a last note, I do wear specs, with astigmatism correction although don't always wear when observing, only to look at the RA/Dec on the scope and which EP I've put in! Eye relief not the most important thing, but would be nice to have some! Budget wise, I had thought of stretching to ~£100 per eyepiece, or equivalent of the Hyperion Zoom at ~£200 for several focal lengths.

Looking forward to hear suggestions/responses; thanks all in advance?

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Edited by pete_81
Adding a bit more detail

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Hi Pete ,welcome as an active member ?

Plossl are great for what they are, cheap nice eyepieces to get you going in the hobby and for the smaller targets.

But really I think a wider field of view eyepiece may be a better option. A plossl to a wide field ,good eye relief eyepiece is like looking through a straw.

My best decision when it came to eyepieces was to buy some used Pentax XW , just quality and so versatile, but these days a bit more than your £100 budget each.

The other quality eyepiece I would suggest is the William optics uwan, found these great for the money ,or I understand the same eyepiece is the SW Nirvana. These are great eyepieces IMO for the cost and a great step up , but without breaking the bank. 

Don't be afraid of getting used kit, as some nice quality items come up for sale on the SGL site, at a considerable saving over the new price.

Hope this helps ?

 

 

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Hi Pete, it's quite a difficult choice buying new ep's because there is so much out there.  My recommendation is the Explore Scientific 62º Series, they have average/good eye relief (13 - 22mm) and work well in fast scopes, they are also within your price range, found here:
https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-62-series-ler-eyepieces.html

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Hi and welcome ?

Please don’t follow my mistake -

My first eyepieces were very basic 0.96” fitting.  Upgraded to basic 1.25” fitting.  Upgraded to long eye relief. Joined my local astronomy club in 2002, members had wide field eyepieces, I upgraded to cheap widefield, ok ish, but fuzzy away from centre field.  Upgraded to more expensive widefield.........

Each upgrade involved cash of course.  It would have been far cheaper in the long run to bite the bullet and get top eyepieces much earlier, and had the benefits years ago.  Not saying you must get TeleVue, less expensive stuff that’s very good is available.  And you can be satisfied with a few top eyepieces.......I have too many but I’m not alone in that.....?

Ed.

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Hi @pete_81 and welcome to SGL.

I am mainly TeleVue, (with the odd Meade and Circle-T), but if starting from scratch, I think I would choose the Explore Scientific 62º Series, as mentioned above by @rwilkey

Also, have a play with the Resources ---> Astronomy Tools ---> FOV Calculator at the top of the page... and it's free!

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2" eyepieces compliment this scope well in lower powers. Lunt 20mm HDC & 24mm ES 82 are top choices with the 20mm Lunt ( SW Myriad, TS TSXWA20) out contrasting the VG Explore Scientific.

Some have great luck with the  Lunt 30mm UFF- but do you really want this size exit pupil? In dark skies it will work.

The 25mm TV plossl is excellent.

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Hmmm, some interesting things coming back here, thanks all :D
Regarding the focal length I should go for for starters, any suggestions on this? I'd thought filling the 10/25 gap with something around 15-20, so looked into the 14mm ES 62, but the eye relief seems possibly a bit short on it. Going to the shorter lengths, I'd look to the 9mm - this would be good for M51, M57, but possibly too short for M31 & M42. A power-per-inch of ~13 and exit pupil of
~1.9mm seems well within the capabilities of the scope, so could use a barlow quite nicely. But is this too close to the 10mm series 500, or is this now getting rid of the 25&10 and upgrading rather than adding to collection?

Or is a high power 5.5mm ES62 going to wow and then save for something in the middle range (15-20)? The eye relief seems to be concern of middle ground ES62, or is that the difference in cost - compromise between good eye relief with the EPs that are good with fast scopes?

As Gerry mentions, trying longer focal lengths seems to be better for the scope, so is the ES62 32mm the ideal starting point, and increase from there? Other than ER, the ES62 look to be great choices, thanks to Philip & Robin. That throws the next question on how good are the 68deg (and even up to the 82deg 4.7mm) which would be top of my single-EP budget for the time being... As I have mentioned before, I do wear glasses but typically not whilst observing, so is the short ER going to throw up an issue at this point...

So, the ER on both the 62 and 68 deg med lens (14/16mm) are short at <12mm, so for something in this range of focal length, should one go to ES 82deg f=14mm; ER>15mm which bumps price significantly, but what is an 82deg EP like compared to the 62 (and my present Plossl choice?!)
For high mag:
5.5mm,               62deg, 13ER => £77
4.7/6.7/8.8mm   68deg, 13-15ER=>£120
Low mag:
32mm                 62deg, >20mm ER=>£120 (2" EP)

Are the 68deg worth almost double the cost? And the 82deg?!

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As the field of view gets wider, ensuring that the view remains reasonably well corrected at faster focal ratios (F/4.8 is fast) means that optical design and execution needs to be more sophisticated and accurate, so the price rises.

If you crave a wide field of view, then the additional costs for 68, 82 or even 100 degrees may well be worth paying (I'm a bit of a hyper-wide junkie myself which has proved costly over the years :rolleyes2:) but if you are content with 50 or 60 degrees then you can save some £'s.

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1 hour ago, pete_81 said:

Are the 68deg worth almost double the cost? And the 82deg?!

The 24mm ES 68 we have is excellent and bought it during one of ES sales events. The 2" eyepieces give a really nice TFOV - the 20mm-25mm range will work well with and without filters and approach the "limit" for less than dark skies IMHO.

As you up the mag with lower fl eyepieces you might want to stay with the likes of (low scatter) orthos, Delos, Pentax XW, Vixen SLV's. Johns review of the SLV line is VG. The Baader zoom is rumored to be good as well.

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Hi John & Jetstream, following on from this then, the 62deg Explore Scientific sounds like a fab upgrade for my use at any level, and I'd guess much nicer than the Plossls. The SLV was a possible option to start with but with the smaller AFoV, maybe they're closer to the plossls? Are the SLV decent with the fast scope? And the Baader zoom was my strong contender but again is it good with the f/4.8?

There's a few reviews from March where John agrees about the zoom being ok for bright objects, but not for nebulae due to lack of contrast? Would the zoom be a good option and later get the 5.5ES62 and 32ES62 or would folks recommend leaving the zoom and doing single focal lengths, like the 5.5 and 14 and 32? This range is approx doubles of each other (there are posts suggesting do scaling of 1.4) but that's for later! On that, are barlows good enough or preference for single focal lengths? 

Last for now, reading jetstream's post, is it better to go for higher quality EPs at the short or long focal length?

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48 minutes ago, pete_81 said:

Last for now, reading jetstream's post, is it better to go for higher quality EPs at the short or long focal length? 

For me, and how I observe, using 100 deg (or 82) in the low range and narrower, low scatter eyepieces in the higher mag range works well. I use the 100's for nebulae (OIII/UHC), starfields and panning -with the orthos, XW, Delos class eyepieces for lunar/planetary/globs/planetary nebula etc.

The Lunt 20mm HDC gives Ethos like contrast and behaves well at f4.8.  The ES line up gives Nagler like performance, IMHO. The SLV will give a low scatter, high contrast and high definition presentation with nice eyerelief and will compete with the more expensive Pentax and Delos in a smaller FOV. This is quite an accomplishment actually.

Bottom line- I use completely different eyepieces for low power vs high power observing, but thats just me..

(ps I love orthos too...)

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Plossls are nice in the same way that a classic car is nice. Simple, uncomfortable, charming but uncomfortable and limited on the performance front (except on axis).

60° to 70° gives a very useful increase in fov. Haven’t tried the ES 62°, but have owned their offerings at 68°, 82° and 100°. They make quality gear for the money.

At your focal length / f ratio a 24mm a 15mm(ish) and and 8mm would be a good starting range.

Paul

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Thanks @John & @Paul73 ? This has cleared up the real issue, which I think I can summarise as:

Expensive lenses will generally have a wider AFoV
Expensive lenses
will work better with faster scopes, where the optics have been designed to keep distortion from the faster scopes (off-centre of EP) to a minimum (across the bulk of the view through the eyepiece
Expensive lenses likely to be longer eye-relief
Expensive will have better coatings and higher contrast

The SLV are similar FoV to Plossl, but for the cost, I think I'd try the 62* as I've never had this luxury, or am I being too narrow minded here?! Am I right in saying that the main gain from the wider FOV is just the viewing angle that the scope/eyepiece picks out, so a wider FOV is in some way equivalent to a longer focal length, thus more of sky in eyepiece (not quite the same, but could one say that a 15mm 50* Plossl has a similar view to a 10mm 75*, so going for a longer focal length, smaller FOV to get wider TFoV is a worthwhile pursuit, or is this just wrong?!

Ignoring the potential lunacy of the above statement, coming back to original post, what about the Hyperions as a stepping stone? Nobody has commented on these, or is that just because they're poor with the fast scope? (https://www.harrisontelescopes.co.uk/acatalog/baader-hyperion-13mm-eyepiece-1.25.html suggests good at f/4, for same AFOV and 2/3 cost of the ES68* - plus the adapters give lots of focal length options in cheaper package, or are these a gimmick rather than anything useful?). If the Hyperion is a possibility, the hyperion13 with the adapter rings and 24mm ES68*, giving FOV>65* and decent eye-relief may be an option for a good focal length range (8-24, but prime lenses here being better than the Hyperion zoom option?) How does eye relief vary with the Hyperions and the extension rings?

Or are the Hyperions not as good, so back to the 5.5/9ES62*, 14mmES82* (for the eye-relief) and the 24ES68* (or even change the 14mm to the SLV15mm)

@jetstream, you mention ES sale events - is this a thing from ES directly (via FLO etc) or second hand through SGL?

Thanks again to all who have responded...

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Hi, Correct me if I am wrong, but I get the feeling that you have not looked through many types or makes of eyepiece. So you are really not sure what certain eyepieces views or comfort are going to produce. Eyepieces can be a very personal choice, what floats the boat of one person can be a extremely disappointing experience for another.

Can I suggest that to save you time and money that you go to a club , Star party or even meet up with another SGL member close to where you live ,who may have some of the FOV or eyepieces you are interested in. You can then try before you buy. Could save you a lot of time and money.

 

Hope this helps ?

 

 

 

 

 

 

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I don't usually recommend Hyperions for use in fast scopes. They are nicely designed and made eyepieces but do show astigmatism in the outer parts of the field of view when the focal ratio drops below F/8 or F/7.

The only ES that I've used / owned was the 24mm 68 degree 1.25 inch eyepiece and that was pretty good and pretty well corrected even at F/5.

One reason for using wide / very wide fields of view is to deliver large true fields of view in faster scopes while keeping the exit pupil an effective size. Another is, with manual / alt-azimuth mounts, the wider field helps with tracking objects at higher powers.

 

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Posted (edited)

Hi guys,

Yes, I'm honestly not sure what to get but as the discussion has progressed and I've written out some ideas, it's become obvious that my initial (and preferred choice just on paper) was in favour of the Hyperions, but this is completely the wrong choice at fast focal lengths. I'd never even considered the ES range in any of the FoVs, and they're now the top contenders (ER is possibly the largest issue with them, expecially wearing specs too ;)), alongside the SLV, remembering I'm budgeting for ~£100 per optic.

So whilst the discussion hasn't concluded with "this is THE one", it's been very useful to get some ideas and rule out the pretty hyperions and point out to me that FoV isn't necessarily the most important feature to aim for (at least not at this time with the limit to budget).

Next step being armed with some good quality EP info is to try them in the scope under dark (and light polluted!) skies. Some local astro clubs also sourced, thanks!

Edited by pete_81

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Posted (edited)

I use some Baader Morpheus. Of those I have, the 6.5, 9 and 17.5 are the best. Gloriously sharp FOV, although some say to only 70+ of the 76 degrees, with effortlessly comfortable eye relief. I use these in tubes from FL4.7 - FL12. They do not suffer in anyway (to my eyes) in the faster scope. I also have the Baader Zoom which to my eyes is better in the slower refractors. It was immediately obvious that the wider FOV was very much going to be "my thing".
 

Edited by steveex2003
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Posted (edited)

I am a glasses wearer, although can observe without them. I find the Morpheus so comfortable and fuss-free that it is simply easier to keep my glasses on, which is I guess the best recommendation I can give them in respect to eye relief.

Edited by steveex2003
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Explore Scientific 82 degrees? Great value and parfocul. I have a similar sized scope but only been into this a year or so. Been buying Myriad XWA 100 degrees (discontinued but available from Europe under APM Lunt) Pentax XW and the ES 82 degrees. It would have been cheaper to just build up a set of the ES 82 degrees from the start and as a beginner with little time to do this I probably wouldn’t notice much difference. Increasing field of view hasn’t been my main priority when doing my first equipment upgrades as it is difficult to find stuff as a beginner.

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Hi folks, coming back to this again

I've taken the plunge and got a 24mm ES 68* and just WOW. Love the increase in FoV angle from the Plossls, (profile pic is camera on phone looking down the EP, hand held).

My next target is the mid-range and think I'm in love with the ES EPs. Made a fancy spreadsheet that shows the calculations of magnification, exit pupil, and TFoV (from both the quoted AFoV and the likely more accurate field stop). With this spreadsheet, I've also added columns to show how much of the EP is filled with different objects - eg the moon takes up ~40% of the 68*ES24, or ~15% taken up by M82 and can compare this to any other EP I'm thinking about.

I was about to take the jump for birthday with a 6.7 82*, then looked and thought about barlowing - there's lots of discussion on this again, but the ES x2 FocalLengthExtender may be just what I'm after - this would allow me to have a 68* 12mm (using the 68-24) with half decent ER, with the possibility of later getting the 82*14mm and effectively having FOVs that would allow the moon to fill 40%, 58%, 80% and 115% of the eyepiece viewing (taken from the 24mm, 14mm, 24+x2 and 14+x2 lens choices (magnifications of 50x, 85x, 100x, 170x respectively) - the TFoVs being 1.3*,0.9*, 0.65* and 0.45* again respectively looking at that possible EP setup.

I guess ignoring the 14mm for now (it may be better to get the 8.8mm), I'm wondering if the x2 is the best choice now so that I'd have a 24 & 12. Is the x2 a good choice that would be financially beneficial as EP collection grows...
What are everyones thoughts on the ES x2? Better than Barlow? The ER won't change, which is fine, probably better. (The TV Powermate is well out of any range, so please don't suggest it!) Do most of you avoid focal-length extenders?

Thanks again :)

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10 minutes ago, jetstream said:

Congrats!

The ES 24mm 68 is a great eyepiece.

Thanks Gerry - any thoughts on the extenders (even the x3 is cheaper than a single EP and from ES, whats the drawback?!)

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Post on:

shows same thing - am I missing something to go for a ES focal-extender as a birthday pressie?!

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I've used the ES 1.25 inch 2x Focal Extender and found it to be an excellent performer as well as very nicely made. very close indeed to the Tele Vue Powermate in optical quality I thought.

Edit: I can see that I posted in the above thread to similar effect - at least I'm being consistent !

 

 

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1 hour ago, pete_81 said:

I guess ignoring the 14mm for now (it may be better to get the 8.8mm), I'm wondering if the x2 is the best choice now so that I'd have a 24 & 12. Is the x2 a good choice that would be financially beneficial as EP collection grows...
What are everyones thoughts on the ES x2? Better than Barlow? The ER won't change, which is fine, probably better. (The TV Powermate is well out of any range, so please don't suggest it!) Do most of you avoid focal-length extenders?

Hi Pete, although I have tried the ExSc Focal Extender and find it excellent I have to admit that I prefer to use eyepieces of set focal lengths and not use a Barlow or extender

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