Louis D

The 31mm Hyperion has an MSRP of $226 (USD) and is on sale right now for $169 (USD).

The 30mm Celestron Ultima Edge is exactly the same optically as about a dozen other UFFs rebrandings, so let's just use the original APM UFF as the reference.  It has an MSRP of $266 (USD) and is on sale for $199 (USD) right now.  I can't help it if folks don't shop around for the best deal on rebranded optics.  I'm pretty sure KUO makes all of them.

That makes for a difference of $40 in MSRP and $30 in sale price.  I'd call that roughly the same ballpark for pricing.  I know if I could upgrade my car for less than a 20% increase in price and go from utilitarian performance to luxury or sporty performance in so doing, I'd be all over it in a heartbeat.  The difference in resale value in 5 or 10 years time would also make it more worthwhile as well to upgrade at purchase time.

2 hours ago, Don Pensack said:

They are in a different league.  The Baader 31 is not as well corrected and exhibits many aberrations in any scope shorter than f/8.

And yet their MSRPs are similar.

I bought a pair of new old stock 100% Sorbothane insoles from the 90s off of ebay and cut vibration absorption pads to put under each tripod foot.  It cut settling time with my 127 Mak from 3-4 seconds to 1/2 second.  It went from unbearable to completely usable.  This was with a Manfrotto 058B tripod and DSV-2B mount.

As my move-up scope from my AT72ED, I bought a used TS-Optics 90mm FPL-53 APO f/6.6 Triplet used a few years back for about $900 shipped.  It has been fantastic.  I love the 2.5" focuser, the camera angle adjuster (beats loosening the diagonal retention screws to angle the diagonal to the side), and the complete lack of false color in focus.  I will say I've not been happy with the slow cool down time of the triplet objective.  Based on this, I'd recommend a doublet.  Getting even an FPL-51 equivalent doublet would be a major improvement over an achromat at these short f-ratios.  Thus, I'd say go for a 102ED over a ST102.  Certainly, an FPL-53 doublet would have correction comparable to an FPL-51 triplet, but the cost is considerably higher than an FPL-51 doublet.  TS-Optics has 102mm ED doublets in both FPL-51 and FPL-53 if you want to compare prices.

Way to be on top of this, @FLO! 

Yes, the other versions I linked to quote 13 to 15 pounds.  I think the variance can be accounted for with whether or not the rings are included in the weight.

OPT is also selling the StarField Gear Series f/7 115mm Triplet for $2,130+tax.  Their description states FPL-53 glass:

The StarField Gear Series f/7 115mm Triplet APO Telescope with FPL53 changes the game in wide field imaging.

The StarField website description does not specify glass type, however.

FLO is including a hard case with theirs.  Orion seems to be the only one else including a hard case.

I wonder how it compares to the TS-Optics PHOTOLINE 115 mm f/7 Triplet, Orion EON 115mm ED Triplet and Astro-Tech AT115EDT F/7 ED Triplet refractors.  It costs quite a bit more (over $1000 more) than any of those, so it might be using FPL-53 glass.  However, why wouldn't @FLO advertise that fact?  Perhaps they can chime in and clarify.

6 hours ago, bomberbaz said:

If you have a slow scope of F10 or slower, this may mean a line filter is less suitable in terms of exit pupil and in such an instance a UHC may be a better option.

It's so difficult to get above a 4mm exit pupil with an f/10 SCT or f/12 Mak, let alone an f/15 Mak.  You need a 40mm or longer eyepiece just to get close to 4mm.  50mm or more is better.  Then the problem becomes you're looking down a straw.

Makes you wonder why the Chinese optics houses haven't come out with their own image stabilized optics.  If they could do it for 1/3 the price of Japanese optics, they'd probably sell a bunch of them.

You can thread 2" filters on the bottom of many 2" to 1.25" adapters.  Just be careful the bottom of the 1.25" eyepiece doesn't hit the 2" filter.

Does StarSense work in Bortle 7 and higher skies with limited sightlines?  I often can see only a few brightest stars naked eye anymore from my backyard thanks to all of the development around me.  I find that SkEye works well for me to get my bearings under these conditions because it doesn't rely on actually seeing the sky at all.  I can point it through trees and buildings to get an idea of what will be visible in the near future as well.  It usually gets me to within 3 to 4 degrees of the target which is generally enough for me to fine tune my object alignment with a finder scope or lowest power eyepiece.

I setup my grown daughter with a 127mm Mak on an alt-az mount attached to a heavy duty camera tripod for camping usage.  It's compact enough to not take up too much space in the back of her SUV.  She and her husband already have a dog and all their camping gear in there, so space is at a bit of a premium.

I'd check my HD-60 set to compare, but I've loaned them out to my grown daughter for her use.  I don't ever recall having any issues fully seating them in a diagonal or Newtonian focuser, though.  The field stop was a bit indistinct in a most focal lengths IIRC, but I always wrote it off as the field stop being positioned incorrectly.  I had never considered poor glass or cementing issues.  I never noticed scatter in the field around bright objects that such flaws usually introduce.  It doesn't mean it wasn't there, just that I never noticed it.

32mm Plossls are always handy to toss into a travel kit even after you've upgraded eyepieces.  I took one to Nebraska in 2017 for the total solar eclipse along with an 8-24mm zoom and ST80 scope.  It was perfect for low power views to center the solar disk and to observe the extent of the corona.  I wasn't worried about any of my kit being stolen while stored in my unattended vehicle due to the low total cost and easy replacement, and yet it was more than sufficient to enjoy viewing the eclipse.

Have a look at the post below in my thread showing through the eyepiece images I've taken through my eyepieces using a field flattened 72ED refractor (f/6).  The 25mm BST is already getting fuzzy while the 32mm Plossls are still sharp to the edge.  The 24mm APM UFF is better, but still not perfect, for a lot more money.  It's up to you if you can live with the inner 75% being pretty sharp with the outer 25% getting progressively fuzzier with the 25mm BST.  In a faster than f/6 scope, the outer field that is fuzzy will grow toward the center and be even fuzzier in the outer 25%.  At f/10, it will be fine, though.

1 hour ago, James9 said:

I had been meaning ask, is there a way of calculating what ep would be better on a fast scope or does it only come from looking through it?

Generally, the more complex and expensive eyepieces do perform better in faster scopes, but not always.  The Baader Hyperion Aspherics come to mind as a counter example.  Despite their price, there are better options at their prices for fast scopes.

Your best bet is to ask on here or CN first before plunking down big bucks on an eyepiece.

TBH, I'd just get the Astro Essentials 32mm Plossl for £29 and put the savings toward another eyepiece.  I never use a 32mm Plossl for critical viewing.  That, and the Celestron Omni line is nothing special to justify the upcharge for the brand name.  The Vixen might be an improvement over either the AE or Celestron, but not enough to justify the price jump (double).  Perhaps at a more frequently used focal length, but not at 32mm.

1 hour ago, James9 said:

Thanks for the continue input. 

Trying to weigh up cost, where I am now, where I might be in the future and so on... no one has screamed I am making a terrible mistake (yet) so I plan to plump for:

1. 32mm Celestron Omni Plossl
2. 9mm Baader Morpheus
3. 5mm Starguider

Thank you all, I have learned quite a lot from your considered inputs. Feel free to still scream I'm making a terrible mistake if need be!

I have the 9mm Morpheus, and it views just about as crisply and contrastily (is that a word?) as my 10mm Delos, just a bit wider in AFOV.  Definitely a no compromise choice there.

You'll want to target 50x to 90x maximum in my experience.  If you can observe very early in the morning, you might be able to go higher before the seeing becomes too unstable.

I figured for under $150 shipped, I'd give it a try.  Due to direct from China shipping, it may miss being a Christmas present.  However, my birthday is 3 weeks later, so it should definitely be here by then for a birthday present.

I've always associated being near the coast with excellent seeing based on the reputation of the Winter Star Party in the Florida Keys for having really stable seeing conditions..

Search for "beginner telescope" in this forum and start reading the dozens of threads on this topic.  You should start to get an idea of what to buy.

3 hours ago, James9 said:

I gather the Nirvana's are just rebranded cheaper versions of the Explore Scientific's? When I said I was tempted by 82 degrees before, it was the Explore Scientific's I was looking at. I discounted the Explore Scientific's on cost so curious about the Nirvana's now. 

No, the Nirvanas are entirely different eyepieces made, IIRC, by KUO.  All ES (and Bresser) eyepieces are made by JOC.  Both are quality options.  JOC used to sell their eyepieces under various Celestron and Meade brandings prior to 2013.  Right now, the only bonafide rebranding of the ES-82s outside of China that I know of is the Opticstar line.  There is some controversy surrounding these that they might be second quality, but that has never been conclusively proven one way or the other.

I just used the flashlight method to measure the distance from the top of the eyepiece to the point where the projected light cone was smallest.  12mm to 14mm is definitely how they view in practice.

Geometry doesn't entirely define usable eye relief or all of the original Morpheus would have the same usable eye relief, but they don't.  The shortest focal length ones have the tightest eye relief despite having the same eye lens diameter and AFOV as all the rest.  I see a similar pattern with the HD-60s going from 9mm down to 4.5m in both measurements and in practice.  In particular, the 4.5mm is quite difficult to use with eyeglasses.  Conversely, the Paradigm/BST Starguiders view remarkably similarly across focal lengths in both eye relief and AFOV by comparison.  This is more similar to the Pentax XL/XW lines which all view pretty much the same across focal lengths in both eye relief and AFOV.  All I can surmise is that there are at least two schools of design for these types of long eye relief and wider AFOV eyepieces that leads to the differences or constancy in eye relief (and AFOV in the HD-60s).

If I could ever get the upper assembly removed from the Paradigms, I would remeasure the usable eye relief.  However, I can't get the upper casing to unscrew from the main barrel as others have done.

10 hours ago, James9 said:

Current thoughts to buy: 

• 25mm BST Starguider
• 15mm BST Starguider
• 5mm BST Starguider
• 2x BST Starguider barlow for 12.5mm, 7.5mm and 2.5mm (2.5mm will give comfortable max usable magnification in both my current scopes)

Forget the 25mm BST in a fast scope, it's not sharp in the outer field.  You're just as well off to get a 32mm Plossl for widest field of view in a 1.25" barrel and save a few bucks.  The 25mm BST also requires quite a bit of in focus, so it won't come to focus in my Dob with a low profile focuser and GSO coma corrector.

The 12mm BST is much better corrected in the outer field than the 15mm, and yields a more usable power across more scopes.

The 5mm is a good choice for highest power in the f/5 scope, but will be all but unusable in the f/10 scope due to the super high power and tiny exit pupil.  The 8mm might be the better compromise choice if it will be used in both scopes.  8mm is about as short of a focal length you'd want to use in an f/10 scope.

Despite owning 6 different 1.25" Barlows (with some duplicated for dedicated binoviewer usage to reach focus increasing that total even more), I've never been a fan of Barlows.  They're clumsy to use in practice as compared to dedicated focal lengths and can cause vignetting, focus, or exit pupil issues.  I have no experience with any current day 1.25" Barlows.  Everyone one of them in my collection dates to the 1990s and was made in Japan.  I've found they had better polish, coatings, and stray light control than today's crop of sub-$100 Barlows.

You won't really need a Barlow in the SCT due to the long focal length.  I consider them merely a stop-gap measure for shorter focal length scopes like your 130 while you accumulate more focal lengths.  After which, you won't find yourself using one much at all.