Louis D

2 hours ago, Ags said:

I have an NLV 9 and 12, but their build quality is so far below the SLVs the NLVs’ Japanese glass is no compensation…

Interesting.  I hadn't heard about NLV build quality issues.  My 9mm LV exudes quality except for the cracking rubber roll-up/down eye cup.

Try to get some pics of the scope's markings in the case so we can properly identify it.  It alone might be worth thousands in like new condition.

The mount when new was about $7500, pre-inflation.  I don't know what the secondary market demand for such a mount is today in your neck of the world since you didn't specify a location.  They appear to have recently sold in the US on Cloudy Nights classifieds for between $2500 and $3500, so quite a hit to the new price.  These Meade mounts don't hold their value like AP, Parallax, Paramount, and other low volume, custom made mounts that can be difficult to buy new in a timely manner.

Nice info, but I doubt the OP will ever see it since they last visited on May 14, 2022.

6 hours ago, Mr Spock said:

I can also see the IP address 

That's cheating. 😄

4 hours ago, Ratlet said:

Often safest.  Nothing like thinking you got a bargain on an expensive bit of kit to only be hit with a massive bill from customs when you it arrives in country.

So far, staying under the $800 de minimus exemption has kept me from having to deal with customs.  Saving 8.25% on sales tax is nothing to sneeze at, either, although some US retailers don't have to collect it if they do less than a certain amount of business yearly in a given state.  I always check all sources state-side and world-wide to find the best deals.

2 hours ago, Moonlit Night said:

Do you not have to buy from Russia to obtain glass produced on the European continent? 

What about Schott?  Isn't it still made in Germany?

Especially because it avoids the 25% "special" US tariff on products from a certain country I won't name here.  And, if you stay under $800, there's no US import tariff due to the de minimus daily personal exemption.  That, and I've yet to see a non-US dealer collect and remit US state sales tax like Euro dealers expect US dealers to do for VAT.  Taken all together, it can often more than pay for the cross-pond shipping costs.  On eyepieces with low shipping costs, it's often a no-brainer to cross ship.

By all accounts, the 16mm NT5 is exceptionally sharp, but with only 10mm of eye relief, fairly tight even without eyeglasses.  The entire T6 line was designed with 12mm or ER because that seems to be the Goldilocks amount for non-eyeglass wearers.  They've become the 82 degree gold standard against which all other  UWAs are judged.

Here are some eyepiece tests of the Tele Vue eyepieces you're interested in from Ernest.

You'll need to translate them using Google or their Chrome browser:

Panoptic 24 mm

Nagler 16 mm Type 5

Nagler 13 mm Type 6

Nagler 5 mm Type 6

Overall, he liked them a lot.

Here's the table with links to fixed focal length eyepiece tests/reviews.

Here's the table with links to zoom eyepiece tests/reviews.

Or, if you get the American-spec Skymax with the 2" visual back or make the mods yourself as I did for my Orion 127 Mak:

The difference isn't quite so drastic.  Sure, there's about a 40% falloff in illumination, but I find it works quite well visually.  This is a comparison image through the 127 Synta Mak:

You can see how the 2" Meade SWA (ES-68) 40mm gets darker due to vignetting center to edge thanks to the 27mm diameter rear port throttling the 46mm field stop.

I finally found a reasonably priced, used Tele Vue Nagler T4 22mm and have been using it at that focal length.

Before that, I used the Astro Tech AF70 22mm which is the same as the Omegon Redline.  It is also 2"-only.  It's very well corrected except for the last 5% of the field that has a bit of astigmatism in fast scopes.  It also has enough eye relief for eyeglass wearers.

2 hours ago, Ratlet said:

Kind of related, but SAEP is kidney beaning?  Which is often confused for the effect you get when you have your eye too close to an eyepiece with a long eyerelief?  One is a design issue, the other a user issue?

Correct.  Spherical Aberration of the Exit Pupil (SAEP).  Basically, not all exit rays across the field of view come to a single point above the eye lens.

Read this post of mine to see some nice animations from @Ruud explaining the different shadow types:

SAEP shadows are in the middle of the field, not the edges.  That same thread has some images I've taken showing the extend of SAEP in various mid to long focal length eyepieces.  To get the ring shadow, the camera has to be exactly level and on axis with respect to the eye lens.  Otherwise, you get the classic kidney-bean shadow to one side or the other.

A few even show Chromatic Aberration of the Exit Pupil (CAEP) with rainbows.  CAEP is caused by different wavelengths converging at different distances above the eye lens.  It's often referred to as the "Ring of Fire" effect.  Small, extended objects like Jupiter near the field edge actually split into spatially separated red and blue images in my experience.

A bit off topic:

Seeing the recent thread on choosing a 4" refractor for visual (Choosing between 4" ED Refractors for visual), and having just compared my 90mm APO to my 150mm Newtonian, just exactly how much improvement would I see going up 10mm to 12mm in aperture to a 4" ED or APO refractor over the 90mm APO triplet?  Would that little extra bit of aperture reveal the Trapezium E component that the 90mm simply could not even hint at?  Should I instead jump to 120mm or 125mm for my next ED/APO?

I've found the SVBONY 68° Ultra Wide Angle 20mm works exceptionally well in my barlowed binoviewer at f/18.  They're light, compact, have enough eye relief for eyeglass wearers, have a decently wide field of view, and are inexpensive.  See my full take on them in this mode below:

I find the well figured, ultra wide field, long eye relief 20mm to 26mm region to be rather skimpy at any price.  There's the 20mm SL/FM, 22mm NT4, and 26mm Meade MWA.  The MWA has excessive SAEP (and is discontinued), the NT4 has some SAEP, and I have no idea about the SL/FM and SAEP.  I'm holding out hope that ES expands the ES-92 line upward to 23mm or so.

For the £10 difference, I would definitely go for the Founder Marvel Ultra Wide 14mm over the StellaLyra 14.5mm 1.25" 68º LER / WA.  It will have a wider field, better correction, and similar eye relief with the eye cup screwed down.  Definitely worth trying Don's rubber band (O-ring) trick if you need the cup up higher to avoid blackouts.

You could also make an adjustable eye cup by wrapping black crafting foam around the outside of the eyepiece, cutting to circumference, and then gluing the ends together.  It could be slid up and down for adjustment.

Another option would be to stack a 43mm to 49mm step-up ring on a 49mm to 50mm step-up ring onto the eye cup thread if it is indeed 50mm x 0.75mm threaded.  You could then thread a 43mm Morpheus eye cup onto the 43mm step ring thread.

The big three Dob makers are Synta (Celestron, SW, and Saxon), GSO (SL, Apertura, and Bintel), and JOC (Explore Scientific and Bresser).  I would look for a local ES dealer to compare a third option.  The GSO ones generally have the most features out of the box while the ES have the best altitude axis (true trunnions).  Synta's Celestron Starsense Explorer app has been well received, but the scopes themselves are unremarkable with antiquated 2" focusers.  They generally require the most tinkering.

Make sure you see how big a 12" Dob is in person before buying one.  They can be quite an armful.  You might consider a truss tube over a solid tube at 12".

On 21/02/2024 at 10:55, Jimmy81 said:

I think I mentioned before about whether the 20mm might be a bit close to the 30mm in terms of magnification, but all will be revealed. If I find them too similar (40x and 60x in my 8” f6 dob) then I may switch the 20mm for the 14mm LER/UWA.

So, let's say you're set at 40x for your lowest power and largest exit pupil (30/6 = 5mm) with the APM UFF 30mm.  Based on my observing preferences after 25 years, my next step up in power would be 70x to 85x, and a 2mm to 2.5mm exit pupil for general DSO observing.  This would be an eyepiece range from 14mm to 15mm to satisfy both criteria.  I would say to give the 14mm Morpheus a try.  It comes with an eye guard extender if you need back off from the eye lens a bit.

Just like the Zeiss Abbe Orthos (ZAOs).  I've seen complete sets advertised for $5000.

How about the 13mm APM HDC-XWA 100° and other brandings by the same manufacturer, if you don't need long eye relief?  Apparently, they're lighter than the competition while still having excellent correction.

There's also the 12.5mm APM Hi-FW and its Sky Rover stable mate if you need long eye relief.  Don dislikes its EOFB, but I've yet to even notice it.  Perhaps if I observed under truly dark skies I'd notice it.  I find it to be very well corrected.

The 12.5mm Morpheus is also well liked if you need long eye relief.  I don't have it, but I do have the 14mm Morpheus and find it very good, with just a bit of astigmatism in the last 5%, although Don reports there being none.  Perhaps I got a dud.  I measure 78° on it, so just barely narrower than the 14mm SL 80°, but in a 1.25 barrel.

I really like the 12mm ES-92, but it is very large, heavy, and expensive.  You might struggle with eye position with it.  Ironically, I've measured the 12.5mm Hi-FW to have a slightly larger field stop than the 12mm ES-92 despite the former being in a 1.25" barrel and the latter in a 2" barrel.  They have opposite distortion as well.  The ES-92, like most astronomy eyepieces, stretches objects toward the edge while the Hi-FW compresses them.

People rave about the 12.5mm Noblex and 12.5mm/10mm Nikon NAV-HW, but both are very expensive.

There's also the 11mm Tele Vue Apollo if you can find one used and afford it.  I believe the limited edition production run ran out.

There are lots of excellent options between 11mm and 14mm.

The US version comes with a 2" visual back, diagonal, and 28mm eyepiece.

If you strictly use it with a 1.25" diagonal and lightweight eyepieces, you should be fine.  However, 2" diagonals will leave the focuser with very little infocus travel left.  Heavy eyepieces with a 2" diagonal may cause the draw tube to slip at high angles as well.

Best not to go down this rabbit hole any further to avoid this thread being locked for being too political.

Don't Leica, Zeiss, and Swarovski still make some eyepieces in Europe for their spotting scopes?  They can be adapted for astronomy use.

4 hours ago, Mumia said:

With such exponential growth of Chinese optics companies, I am more concerned about our local European manufacturers

I don't know about European optical companies, but US ones will always have DoD contracts to fulfill for the US military.  That's what keeps Vernonscope afloat.

Could there be a promotion/relegation in the works?