Louis D

The Wild design is reminiscent of the Panoptic design:

2 hours ago, Mike Q said:

The Chinese have been making glass for 2000 years, while the mirror in mine is pretty good, you would think that by now they would have figured out how to make it better lol.

It is curious Chinese made ED and APO scopes usually use Ohara or Shott glass.  You'd think China would have mastered making optical glass by now.

When held up to a bright, white background with extraneous light blocked between it and your eye to keep reflections at bay, I would think the OIII would appear blue-green, the HA would be deep red, and the SII would appear super deep red, almost black because it's approaching the limit of human eyesight.

Ernest over on CN posited in this post that the following apparent fields of view (AFOVs) in degrees will not show coma at the following f-ratios (simply square the f-ratio):

• F4 - 16
• F5 - 25
• F6 - 36 (classic ortho will have whole thir FOV free from coma)
• F7 - 49 (super plossl are coma free in F7 Newton)
• F8 - 64 (WA eyepieces are coma-free in F8 Newton)
• F9 - 81 (even Naglers are coma free in F9 Newton!)

Thus, at f/4, you're looking at a coma free field with a 16 degree AFOV eyepiece.  Those Morpheus and Panoptics, being well corrected to the edge at f/4, would show coma at f/4.

I know I observed for about 15 years without using a CC because I didn't notice it, it having always been there.  However, I started upgrading and widening my eyepieces about a decade ago and started noticing the coma and decided to get a used GSO CC for $75 to try out.  It was an amazing difference.  I didn't think I'd notice, but it was quite obvious to my eye at least when the CC is in or not in use even at f/6.

You'll definitely notice an improvement with both the Morpheus and Panoptic eyepieces.

For the GSO CC, I add a 25mm spacer ring between the eyepiece holder and the optical nose piece to get to the 75mm separation sweet spot with a 1.25" adapter typically adding another 5mm of separation.  The CC designer has stated elsewhere that 5mm on either side of the design separation is almost indistinguishable visually.  I've found that to be true.  Eyepieces that focus within 5mm of their shoulder (reference plane) don't show enough improvement to bother with parfocalization.  However, I had to parfocalize my 12mm NT4 with five 4mm thick O-rings because it focuses 20mm below the shoulder which led to noticeable uncorrected coma.  So little 2" barrel was left that I had to add a 20mm M48 spacer ring.

It depends on how wide and well corrected your eyepieces are.  Once in a while I pop in one of my ES-92s without putting the GSO CC in first and get apprehensive about why they're performing so poorly at the edge even at f/6.  Then I realize I have forgotten to put the CC in the focuser first.  Put it in, and my stress levels decrease markedly.  As mentioned above, the GSO CC will add SA at high powers, so I remove it for high power observing.  I do the same with my TSFLAT2 in my refractors to get the sharpest on axis images at high powers for the same reason.

If you're just using 40 to 50 degree orthos and plossls at f/4, other edge aberrations such as astigmatism will completely overwhelm any coma from the mirror because these simple eyepieces were simply not designed for fast scopes.  A CC will help flatten the field and remove coma, but eyepiece aberrations will remain.

If you're using Nagler and Ethos eyepieces, you would naturally want them to perform at their best and add a TV Paracorr T2, so it depends on your eyepiece collection.

BTW, at f/4, the coma free section on axis is only 1.4mm (0.022mm x f-ratio³) in diameter for the comatic aberration to fit within the Airy disc.  A TV Paracorr T2 will extend that to at least 40mm.

On 18/02/2022 at 04:25, Mike Q said:

Ohio skies suck.  You can have a clear night, but either seeing or the transparency will be terrible.  Even out in the boondocks  where I live we are a 4 on the Bortle scale.  In the last 6 months we have had 2 nights that have been really good.  

Sounds like you need to move to Texas.  Excellent seeing on many clear nights, and winter nights are mild.  That, and you don't have to deal with snow and ice very often, and cars never rust out due to road salt.  We really need more upper Midwesterners moving down here to balance out all of the Californians moving in.

As far as mass production Dobs vs custom Dobs, I really notice the difference in the motions and focusers.  Balance, smothness, and sticktion have been well thought out in custom Dobs and their focusers tend to be buttery smooth in use (Feather Touch, MoonLite, or similar).  I don't have the time to tinker with a scope to perfect it.  I'd rather pay someone local to the US or Europe to build it right from the start.  Does anyone espouse buying Chinese made cars over US, Japanese, and European cars, and then upgrading all the bits and pieces to make them road worthy?

19 hours ago, Don Pensack said:

An observation: the 12mm and 17mm ES92s are not free of SAEP either.

A lot of people have noticed this.

True, but based on my comparative imagery through my 127 Mak and a slow, ultrawide smartphone camera, it's much less than the NT4s:

The 12mm and 17mm NT4s SAEP make it all but impossible for me to take in the entire view once you push in close enough to see the field stop.  They're not as bad as the Meade MWA 26mm which also has some CAEP, but you expect better from Tele Vue.  I felt betrayed by Al.  They were his 3rd released iteration of 82 degree eyepieces.  There was no excuse for leaving SAEP in the design at that time (let alone at that price point).

33 minutes ago, Mr Spock said:

Looks good. You'll be seeing my 12" unboxing shortly 

Keep it clean, this is a family oriented forum. 😙

22 hours ago, cajen2 said:

Beware of relatively low eye relief with the Nirvanas (12mm). Worries some people more than others.

FYI: Hyperflex Zoom FOV 60-40° . 15mm eye relief.

I bought a generic version (Wollensak) of the Hyperflex 7.2mm-21.5mm from Surplus Shed, and I measured the usable eye relief to be around 10mm.  Just look at the tiny eye lens (16mm diameter) and how much it's recessed (it's the third eyepiece from the left), and you'll understand why.  The Celestron Regal 8-24mm zoom is second from the right.  I unscrew the entire eye guard to use it with eyeglasses (15mm of usable eye relief with its 26mm diameter eye lens).  There's really no way to use the Wollensak with eyeglasses except to see the central portion of the view.

2 hours ago, Mr Spock said:

Agreed. My former C9.25 was capable of spanking any refractor out there. Providing the seeing conditions were right of course and it was properly collimated. 
SCTs have to be collimated spot on. Only slightly out and you get mush. I've had an easy separation of an 0.7" double with that scope.

I'm jealous you got to compare views against a 9.25" refractor.

1 hour ago, johninderby said:

So you can set both zooms to exactly the same setting. Without the clickstops would be hard to have both zooms set the same or you would have to fiddle around to try and get them the same.

Sorry to hear you didn't get on with non-click stop zooms in a binoviewer.  I've had no problems.  I just roughly zoom the two eyepieces until I reach the desired magnification in my dominant eye.  I then zoom the other eyepiece back and forth a bit until the image scales and field stops merge.  It usually takes less than second.  It's much easier to tell when best magnification matching has been achieved than when best focus in monovision has been achieved.  The two images just snap together all of a sudden.  I've never experienced eye strain using them.

Check out this almost 7 year old AMA bulletin about blue intense LED outdoor lighting.  Perhaps refer to it when complaining locally.  There's probably a UK equivalent warning out there as well.

4 hours ago, saac said:

If by elitist you mean: requiring critical thinking skills, perseverance, resilience and enthusiasm for learning then yes I would agree. And long may that continue - God forbid we ever fall to the instant gratification of the social media/celeb/reality TV, TIK TOK, Instagram  mindset. 

Jim 

It's pretty obvious based on turnout at public star party outreach events around here that only a tiny fraction of the population have any interest in amateur astronomy, even in or near big metro areas.  In my experience, those interested tend to be families that want to broaden their kids' experiences or are adults that come from techie backgrounds with an insatiable desire to learn new things.  Elitist perhaps, but many of these same people drive technology forward for the betterment of the other 99% of the population.

Domo arigatou misuta roboto is the extent of my Japanese. 😉

The coolest part is I used to design IBM mainframe and super computer processors and systems.

44 minutes ago, johninderby said:

BTW will the APM wonder zoom every be released? Allways seems to get delayed.

April 29th is the latest APM delivery date according to this most recent post in the CN Vendor Forum.

And don't forget that some Maks use undersized primary mirrors, so they don't actually operate at the aperture of their corrector which diverges the incoming rays and requires an oversized primary to collect all of them.  For instance, the Synta 127mm Maks actually operate at about 118mm from what I've read.  The JOC 127mm Maks do actually operate at 127mm from what I've read.

18 minutes ago, michael.h.f.wilkinson said:

Or the 12 and 17 mm ES 92 deg

 

Now that I think about it, I retired my 12mm and 17mm NT4s after buying the 12mm and 17mm ES-92s.  Huge improvements in eye relief, usable field of view, and SAEP control going to the latter.  Also, a minor improvement in field flatness with the ES-92s.

3 hours ago, Dixie said:

Between an 8 inch Edge and a four inch refractor under anything but the poorest conditions the former will provide  more detail.

I already pointed out that the 8" EdgeHD displays stunning planetary views.  To reiterate, in my experience, it's standard 8" SCTs that always seem to show mushy, low contrast views of planets in comparison to 8" Dobs with hand figured mirrors and 20% or smaller secondary obstructions.

I have actually been surprised they've kept them in the line up for this long.  I have a feeling they finally ran out of new old stock at corporate warehouses to supply dealers rather than stopping production recently.  I think this was the case as well for Tele Vue's recent product discontinuations like the 12mm and 17mm NT4s.  Once NOS ran out, it was probably determined to be uneconomical to order a new batch to be produced, especially given the 13mm NT6 and 16mm NT5 being so closely spaced with them.  They can just point buyers to the 12mm and 17.3mm Delos if they want long eye relief.

I only use zooms in my binoviewer where changing a pair of eyepieces is a pain and when traveling light, as to 2017's solar eclipse.  I use the discontinued Celestron Regal 8-24mm zooms to good effect.  They were also sold with Olivon spotting scopes.  They're pretty decent, but I much prefer fixed focal length premium eyepieces for general usage due to their longer eye relief, better polish and coatings, wider field of view, and better edge to edge correction.

Long eye relief at high power (<1mm exit pupil) isn't a must for an eyeglass wearer unless you've got really strong astigmatism (>2.0 diopters).

As an f/13 scope, it is going to be pretty gentle on eyepieces.  Also, you probably won't want to go much below an 8mm eyepiece to keep the exit pupil above 0.6mm which is already pretty tiny and prone to exposing floaters in the eye.

2 hours ago, cajen2 said:

The usual advice for a reasonably-priced EP range is BST Starguiders.

Eye relief is right on the edge for you at 16mm.

12mm usable thanks to 4mm of eye lens recession for all but the 25mm which has 17mm of usable eye relief.

Crazily enough, on that webpage, TV says their 1.25" PMs are parfocal in ALL (their caps) 1.25" diagonals and prisms.  I would expect them to be parfocal in Newtonian focusers as well.

@ninjageezer Double check that your truss poles are extended all the way and locked.  However, if the eyepiece focuses without the PM, it should focus with it based on my reading of the above TV PM webpage.

29 minutes ago, Peter Drew said:

I you really want to see the difference between a small and large telescope, have a look at a globular cluster.     🙂

Yes, GCs are very disappointing in a 90mm APO compared to an 8" Dob, let alone a 15" or larger Dob.