Louis D

Sounds like you need to find a used 5-8mm Speers-Waler Zoom (Varifocal).  It works quite well as long as you're okay with refocusing during focal length changes and can live with 10mm of usable eye relief; although it's much longer if you don't try to see the entire 78-80 degree AFOV field at once thanks to its 25mm diameter eye lens.

20 minutes ago, Don Pensack said:

You can download a 2022 guide to all eyepieces here:

https://www.cloudynights.com/topic/813708-2022-eyepiece-buyers-guide/?p=11746324

Everyone keeps mentioning the Vixen LVW, but I don't think most people realize they were discontinued around 15 years ago.  There can't be that many used ones around by now.

But 70-85° with long eye relief in 20-22mm?

StellaLyra 80° 20mm

Orion LHD 80° 20mm

TeleVue Nagler T4 22mm

Pentax XW 20mm

Omegon Redline 22mm (also know as Telescope Service Expanse, Tecnosky SWA, Astromania SWA), and the (now gone) AT AF70 and Olivon 70 and Arcturus 70 and Celestron Ultima LX

There may be others, but I can't remember them off the top of my head.

If you were referring to me, I was quite aware of your comprehensive guide.

I'm perfectly aware that the LVWs were discontinued years ago, but if you put out a wanted ad on US astro classifieds and offer $300 or so for a used one, quite a few offers will inevitably turn up.  I took a pass on them in the late 90s after comparing them to the Pentax XLs and liking the latter better.  Perhaps I should have gotten the 22mm LVW back in the day, but it was (and still is) a focal length I rarely use.

You pretty much repeated my list of 20mm to 22mm eyepieces if you exclude rebrandings of the same eyepieces.  The only other one I though about including was the 22mm Oberwerk since it is uniquely 1.25" and 70°, but typically are only sold in pairs except for their recent remainder sale of the previous version on ebay.

6 minutes ago, cajen2 said:

553g without lens caps, Z.

Weight wise, that puts it squarely between its two nearest LER competitors that I own, the 22mm AT AF70 (Omegon Redline SW, etc.) at 494g and the 22mm TV NT4 at 680g.  There's also the 20mm Pentax XW at 365g, but it suffers from field curvature, so I've never bothered with it.  The 22mm Vixen LVW comes up short in AFOV at 65 degrees.  I suppose I could include the 20mm APM XWA HDC which reportedly yields about 70 degrees AFOV with eyeglasses.  It weighs 680g, so basically the same as the NT4.  Since the Astro Tech version costs $250 right now, it's a very close competitor price wise as well ($12 more once VAT is subtracted).  The 17mm ES-92 has a field stop nearly as large as the 22mm AF70, so it could also be included in a LER comparison.

Any other 70 to 85 degree LER eyepieces in the 20mm to 22mm range?  I keep hoping ES will release a 23mm ES-92, but that seems highly unlikely now.  There's the 21mm Ethos, but paying that much for at most 70 degrees AFOV with eyeglasses seems like a total waste of money.

My only concern would be the trunnion supports bowing outward at some point over the next decade.  Starmaster telescopes have had this issue despite using red oak plywood.  The culprit tends to be moisture intrusion warping the lumber.

I once looked through a 17.5" Coulter Dob at a star party a couple of decades ago, and I can't say that the views were all that impressive.  Not bad, but not exceptional like a modern Zambuto or Lockwood mirrored Dob.  The fact that the guy kept an ancient 12 passenger van with custom wood cradles in the back to haul it around, and had to get a couple of extra folks to help him extract it and set it up, put me off of getting one.  I went with a used 15" Tectron Dob with a Nova Optical mirror instead.  It was great until my back got ripped up by a car accident.  That 65 pound mirror box is killer.

Sometimes, it comes down to which way you can reach focus and which way looks better corrected.  I've heard both ways.  TV claims the CC should be kept at the same distance from the eyepiece, so it would slip into the Barlow.  Myself, I leave out the CC (a GSO as well) because at higher Barlowed powers, the residual coma doesn't bother me much at all.  Your best bet is to get out there under the stars and experiment.  It's not like something is going to short circuit and explode in your face. 😁

4 hours ago, Ian McCallum said:

Three Barlows, was the headline.  I thought it was something to do with Ken, Deidre and Tracey!🤣

Had to look that one up since that show hasn't made it to this side of the pond.  Good one. 👍

You might try cross posting this question on CN's Classic Telescopes forum as well since you suspect it's an Edmund objective.

You could go cheap with an achromat refractor and image with a green filter like a 56 green possibly combined with a 12 yellow to filter out the unfocused blue and red light.  You could then switch to grayscale in post to replicate the green channel to the red and blue channels.

Notice below for an achromat (the dotted green line) that if you restrict it to the spectrum range between 500nm and 600nm (hard to see due to the transparent background around the edges, but they're the 2nd and 4th horizontal lines from the bottom), you can get pretty tight focus.  That's roughly the color range from teal to orange.  Now notice that if you combine a 12 yellow filter with a 56 green filter, you'll do a pretty good job of selecting the 500nm to 600nm range.  Since the sun and moon are so bright anyway, you can afford to lose roughly half the light intensity within that range.  This would not be a good approach for dim, full spectrum objects.  You might not even need to stack the 12 yellow depending on the particular characteristics of the 56 green filter.

You can't use a solar wedge with a Celestron Nexstar 127 SLT.  They can only be used with refractors.  You'll need to use a full aperture solar filter such as Baader Solar Film unless you either already have a refractor not listed in your signature line or are planning on buying one.

The 127 Mak should take fine images of the moon.  Given the 1500mm focal length and crop factor of your camera, the full moon (or sun with filter) should just fit on the sensor in one go at prime focus to avoid stitching images together.

Interesting.  I just measured the Meade 140 distance from the bottom of the chrome tube to its insertion shoulder and got 85mm.  Thus, if I'm seeing 3.0x in my binoviewer, and it takes an additional 45mm extension to get to 3.0x, my binoviewer must have a 130mm optical path length.  That's a 30mm longer than I had guessed, probably because I have to screw the nose piece into the BV's insertion barrel filter thread since it uses a nonstandard thread size to attach to the BV body.

There's also the optically-same Meade UHD, Celestron Ultima Edge, Tecnosky Ultraflat, and Altair Ultra Flat versions.  Perhaps one of them might be in stock.

3 minutes ago, Carl Au said:

Afternoon tea man here, preferably Darjeeling 

I'm an iced tea man myself, it being so hot most of the year here in Texas.  I prefer it freshly brewed and strong.  In fact, so fresh it melts the ice so I have to add more to cool it to near freezing, thus the need for it to be brewed strong.  Nothing offends me more than instant iced tea from a mix served from a beverage fountain.  Ugh, disgusting.🤮

I did a write-up here comparing the 30mm APM UFF to the Tele Vue equivalent 27mm Panoptic along with the 30mm ES-82 and a 30mm generic 80 degree Wide Scan III clone.  Reportedly, the 28mm ES-68 has better eye relief than the Panoptic, but has poorer edge correction beyond the 80% point.  I do have the 40mm Meade 5000 SWA which is the same as the 40mm ES-68, except for eye relief, and really like it a lot.  I actually prefer it to my 40mm Pentax XW except its ergonomics  being broadly flat topped.

36 minutes ago, Carl Au said:

Interesting, in what way? 

Think Wild West versus Afternoon Tea.

And that exact amount would be, what????  I get exactly 3x using the Meade 140 nose piece on my Arcturus binoviewer, so probably 100mm or so of separation.  By itself as originally packaged, I get 2.4x.  Both of these measurements were with a 14mm Pentax XL that focuses pretty close to its shoulder.

On 09/03/2022 at 17:06, CCD-Freak said:

Admiral, there be whales here! 🐋

Rick Singmaster of Starmaster Telescopes preferred using teflon pads riding on FRP (Fiberglass Reinforced Plastic) wall board (or glass board) for the azimuth bearings.

Each eyepiece focuses at a different point relative to its shoulder or reference plane.  Those requiring an extension tube have their focus plane below the reference plane.  An alternative to the extension tube is to add an extension ring to the filter threads and add rubber O-rings to push the reference plane downward as I did with my 12mm NT4.  This made it nearly parfocal with most of my other eyepieces that focus very close to their shoulder.

I also took a group shot of all my eyepieces, Barlows, and binoviewer for good measure while I had them all out.

I was never satisfied with the LG G5 "full view" images, so I did some research and found that the LG G6 has a much better ultrawide angle camera.  It's slightly narrower in field of view (125° vs 135°), has higher resolution (13MP vs 8MP), and is much lower in noise and artifact levels.  It's still considered a 2mm f2.4 lens.  I finally snagged a used one for cheap in excellent condition for my needs (it can't read a SIM card).  I then proceeded to retake all of my ultrawide angle AFOV images under the same conditions as before, edit them, scale them to match the image scale at the center of the older Samsung Galaxy S7 images, and substitute them for the older LG G5 images.  All of the original Samsung Galaxy S7 images soldier on because I couldn't improve upon them with either LG's regular wide angle camera.  There's also a few new eyepieces in the mix that I have acquired since I posted the first batch that I decided to include.  I also retook all of the group shots since so many had new members.  This time, I took them with their eye cups folded down where possible to make it easier to see their eye lenses.

Without further ado, here they are in one mega post.

3.5mm to 6mm eyepieces:

6.5mm to 8mm eyepieces:

9mm to 10mm eyepieces:

12mm to 12.5mm eyepieces:

13mm to 15mm eyepieces:

16.7mm to 17mm eyepieces:

18mm to 22mm eyepieces:

23mm to 28mm eyepieces:

29mm to 30mm eyepieces:

32mm to 42mm eyepieces:

6 hours ago, vlaiv said:

That is some serious blue ring of fire!

I saw that as well, but it doesn't prevent me from wanting to collect one someday if I won the lottery. 🤪

Having a big objective lens at the front of a telescope does not generally equate to a wide field of view.  It does equate to more light gathering ability as compared to a smaller front objective.

On camera lenses, sometimes a large front objective lens does equate to both a wide field of view and large light gathering ability as with the old Nikon 6mm f/2.8 fisheye lens:

14 hours ago, 04Stefan07 said:

you can clean it with a good quality metal polish

I'm assuming one with pure ammonia and no abrasives or sealant waxes.

The refractor will cool down considerably quicker than the Mak.  If you can get the refractor for the cost of a new Mak, I'd go that route.  The 80ED is roughly double the price of the 127 Mak here in the states.