Louis D

You can try setting it on a water butt stand to raise it up a bit.  It's probably a good idea anyway to get it up off the ground to keep crud out of the AZ bearings.  You don't want them to get fouled.

How about posting a photo it?

Definitely observe some of the brighter, somewhat compact open clusters.  Photographs don't do them justice.  Also, try some of the large globular clusters like M13.  Lastly, view some of the brighter planetary nebula like M57.

27 minutes ago, Geoff Barnes said:

I've often wondered what eyepieces are used in professional observatory telescopes and are they available to mere mortals like us? 

Would they be likely to use Televue ep's?

Back in the day, there was a line of Zeiss professional monocentrics mentioned in a post on CN.  I'll cut and paste the text from CN user vahe here since it bears worth repeating:

As promised I contacted my fried who owns these pro Monocentrics with additional questions, here is his reply:

“Here is some more information about these remarkable oculars.

1) The focal lengths I reported to you for the Professional Monocentrics are correct, and there were no other focal lengths made. None of these eyepieces were available from either standard or limited production. They were only custom made for observatories to use with various large Zeiss telescopes and astrographs. They differ from the amateur monocentric designs in 5 ways: first, the spec level on the design was much more tightly controlled and the level of polish was reported to me to be about twice as fine as the amateur oculars- the highest level Zeiss Jena was capable of; second, they were designed to work down to f/4 whereas most of the f/l's in the amateur monocentrics were designed to work down to f/6; third, they are highly corrected to provide a flat field over a large area to match the large film plates used in the various Zeiss camera systems; fourth, they incorporate some glass types that were not employed otherwise and were proprietary Zeiss melts; finally, they were much more expensive originally than the amateur monocentrics, which is understandable given the custom nature of their production and the extremely fine level of design and finish. I have never seen one advertised for sale anywhere.

2) Both the 35.7mm and 41.4mm were made in two versions. One is the solitary monocentric, and the other adds a field lens to the assembly so that in these longer focal lengths, the field curvature continues to be controlled over very large areas- for the fastest observatory astrographs Zeiss made. I have both versions, and after 15-20 years of careful comparison prefer the one with the field lens as it is more highly corrected and the field lens completely disappears in use. The field lens appears to be more extensively coated than the monocentric assemblies, whatever the case, I simply can't see it in the light path.

3) I would agree with your European friend that the 18.5mm Professional Monocentric is a special ocular, however I have found it to be second to the 24.6mm. This is after comparisons in both fast and slow 8" triplets, the 10" Maksutov, and three Zambuto reflectors from 12.5" to 20" in aperture, as fast as f/4.3 uncorrected for coma.

4) Over a long period of time, I have compared these eyepieces to sets of the original ZAO's, ZAO II's, amateur Zeiss Monocentrics, and three other brands of monocentrics. The Zeiss Professional Monocentrics are notably superior in every focal length. So much so, that I have sold all of the others except for a few outstanding f/l's that seemed to me to be the standouts in the other Zeiss designs- e.g. 25mm original ZAO; the 10mm and 16mm amatuer Zeiss Monocentrics. I did not keep any of the other brands of "monocentrics". In my opinion, there is a bigger difference in low level contrast, sharpness, and detail in the Professional Monocentrics and the ZAO's than between the ZAO's and other high-end orthos or the most highly touted of the other "monocentrics".

5) When used in combination with high quality barlows or Powermates, the Zeiss Professional Monocentrics remain notably superior to comparable effective focal lengths in any of the other eyepeices I have used, including the ZAO's. This is what surprised me the most, originally, but my experience has continued to confirm it over time. This result provided remarkable flexibility early on, before I acquired the complete sets of focal lengths. It allowed me to design two planetary telescopes around a couple of the eyepiece focal lengths, especially the 24.6mm, then vary a full range of planetary powers with various barlows or Powermates.

It is my understanding that only about three dozen of these were ever made. I eventually located and purchased most of them, paying very dearly to complete some of the f/l's. The observatories who had them were in six different countries, and as they switched from film to digital during the 90's and early 2000's I was able to acquire them directly. The most any single observatory had was 2 focal lengths, so its been quite a project and the last one I located was around 2006. There is a number, in the single digits, that seem to have disappeared over time. It sounds like one of your European friends might have a couple of those and is enjoying them very much. I thought it made sense to locate and secure these before they all disappeared as they are both historically significant and in use, pellucid and sublime."

Vahe

Update on this thread.  Meade is now owned by Orion USA as of June 1st, 2021!  Basically, the bankruptcy court awarded Orion substantially all of Meade's assets to settle the lawsuit that led to Meade filing for bankruptcy.  My prediction that this would happen was correct!  Had Ningbo Sunny simply paid $500,000 or so like Synta/Celestron did to settle out of court with Orion, they would still own the Meade brand.

Optronic Technologies, Inc. (dba Orion Telescopes & Binoculars) ("Orion") (est. 1975) today announced the formation of Meade Acquisition Corp. (dba "Meade Instruments"), an affiliate of Orion that has acquired substantially all of the assets of Meade Instruments Corp. ("Meade") (est. 1972), following the approval of the United States Bankruptcy Court for the Central District of California.

6 hours ago, Deadlake said:

I thought Nikon’s NAV-HW line where a spin off from their microscope lines?

I've never heard that.  I highly doubt it because microscope eyepieces are generally compact for binoviewer usage.  I could believe the NAV-SW being a spin off of either microscope or spotting scope eyepieces, though, since they are so compact.

I recall reading on CN (but I can't locate the discussion now) that Al Nagler related a story at a star party of having met some Nikon optical designers at some point at a conference or some such.  They freely admitted that they reverse engineered the Ethos eyepieces as the starting point for the NAV-HW line.  Since TV never patented the design, and it was merely the inspiration for their design, there were no hard feelings.

A 127mm Mak or Heritage 130p/150p would probably tick most of your requirements boxes.  The Mak would excel at higher powers after a 30 minute cool down.  The Heritages would excel at lower power views while still being quite capable of higher powers.  Don't forget to figure in the cost of a mount for the Mak.  The Heritages will need something to set them on.  5" SCTs don't typically provide as good of views of planets as Maks of a similar size.

I don't know if your budget would stretch to a 6" SCT or 150 Mak.  You might also look into finding a used 8" SCT.  Older ones are cheap as chips in some cases because so many have been sold over the past 50 years.  A well collimated and well cared for 8" SCT will run rings around most 5" or 6" CATs and reflectors.

A related question would be, would Nikon have come out with the NAV-HW line if the Tele Vue Ethos hadn't already proven a market for them?

Would other companies have made well corrected 82 degree UWA eyepieces if the Tele Vue Nagler T1 hadn't already proven a market for them?

Maybe they would have eventually, but I'm pretty sure TV lit a fire under their collective behinds to play catch-up.

Even military eyepieces of the 1960s to the 1980s with their huge per item price and huge sizes weren't really up to the level set by TV in the 1980s and beyond.

35 minutes ago, parallaxerr said:

3. There's a small floating donut shaped ghost reflection on bright objects - assuming it's the primary reflection.

That's usually caused by reflections off of the interior of the rear baffle tube.  Try putting flocking material in it.  Generally, just roll it up in a tube after cutting it to length and push it up in there without removing the sticky backing covering.  Friction will tend to keep it in place.

It seems like fewer Brits than Americans live in homes large enough to have a dedicated workshop, whether it be in a shed, part of a garage, or in a basement.  It really helps to have a place to store and use power tools for wood or metal working.

Australian homes rival and even best American homes for size on average.  I wonder if Australian ATMs are more prevalent than UK (and American) ATMs as a result?

The heavier one probably has a chromed brass barrel that accounts for the extra weight.

I take the back seat out of my Chevy Astro van and put the solid tube Dob vertically in a corner in the back corner.  It's packed in with other gear, so it doesn't fall over.

I also have a 15" truss Dob that folds up into a 24" square cube with the truss tubes in a slip case.  The challenge with it is that it weighs over 100 pounds packed.  It takes two people, one on each side handle, to lift it out of the back of the van onto a wheeled platform to move it to the observing location.

IIRC, the 56mm fetches $185 to $225 or more on CN classifieds, the 40mm a bit less, and the 32mm is in the ~$130 range.  Given that they all appear to be in mint condition, you might be able to get a 20% or so premium for them.  All this assumes a similar level of demand for them in the UK as in the US.  Probably $450 to $550 (converted to GBP, of course) for the set would be fair if you don't want to break them up.

2 hours ago, jetstream said:

Just saw this- I dislike long heavy eyepieces in my refractors. The Televue Naglers and Delites seem to be "made" for the fracs IMHO. I dont find myself reaching for the Delos etc in them instead enjoying eyepieces like the Nagler 16t5.

I must mention- my stock TSA120 focuser easily handles the massive ES 30 82/ heavy Zeiss/Baader 2" prism diagonal at zenith. It is also easy to adjust and holds adjustment well.

Yeah, not a fan of heavy eyepieces in my smaller fracs due to them causing my alt-az mount to turn turtle above 60 degrees altitude or so.  To counteract this, I hang about 2 pounds of weight off a bolt sticking out 4 or 5 inches at 90 degrees to the telescope tube from the mount's altitude axis itself.  It rises perfectly in opposition to the eyepiece in the diagonal to keep things in balance while doing almost nothing to cause imbalance at lower altitudes.

6 hours ago, ian2 said:

wider than necessary gap between eyepieces in case I obtain physically bigger eyepieces in the future.😉

Actually, I consider 2 blocks the minimum, but 3 works better long term.  Over time, the separator blocks can tend to tear away from their neighbors, depending on how tight the fit is and how rubberized the exterior of neighboring eyepieces are.

1 hour ago, vineyard said:

@Louis Dthe mildew sounds scary (part of me wonders whether that's the heat & humidity of tropical Gulf of Mexico but you're 200 miles inland - is that the famous Texas dustbowl?).

No, it's just slightly less humid.  You have to go at least another 200 miles inland before it starts getting arid.  It's still pretty humid out there, though.

I keep my astro gear stored indoors in my climate controlled house and have had no degradation to any surfaces including mirrors after 20+ years.

Some stuff stored in my shed gets a layer of mildew and/or rust build up over time, so I would never put anything valuable in there beyond a lawnmower.  I'm in Texas about 200 miles from the Gulf coast.  Dew points in the summer tend to be in the mid-70s (about 24 C).

If you can keep good air circulation through your shed, you might be okay, though.

4 hours ago, AstroMuni said:

Simple answer is that tracking is following objects as they move across the sky and that speed is constant for stars and different for the moon. So your F ratio has no bearing on the speed. If you had the same eyepiece on fast vs slow scope all that would change is the FOV as someone has pointed out already. 

You responded to a "member" who posted exactly that one post in 2018 and never visited again.

4 hours ago, CodySydney said:

I know this is a ridiculously old post but this was a real dawn-of-realisation moment for me.  I've been trying to figure out why focal length has anything to do with lens speed... doesn't aperture = more light?  And your post finally got through to me.. of course! focal length -> narrow field of view -> less light = how did I not get this until now.  So I hope you're still living the dream and thanks!

Assuming a fixed aperture.  If aperture is allowed to grow in proportion to focal length (constant f-ratio), you get the same amount of light but at a higher magnification.  That's the draw of big, fast Dobs.  You get increased image scale at the same image brightness.  That, and increased resolution, so it's a win-win proposition all around.

There's nothing to fix.  There's no up or down in space.  You just get used to it in short order.  Adding a rectifier with internal roof prisms will degrade the image quality.

If you really want to view objects right side up, stand on the opposite side of the scope and lean over it looking into the eyepiece upside down.  The two will cancel out and the image will appear right side up to your brain.

I think my only vintage Meade eyepiece is the 14mm 4000 UWA smoothie.  It's pretty well corrected for a nearly 40 year old design.  However, stray light control is abysmal.  It's definitely not a lunar or solar observing eyepiece.  I picked it up for under $100 due to cosmetic flaws.  I just wanted to see if it was really "all that".

I also have some more modern Meade gear.  Two sets of Meade RGB interference filters (one set picked up on clearance for $20 or $30 and another set packaged with a used filter wheel deal) and the 40mm 5000 SWA.  The filters have so much higher transmittance than dyed filters that it's remarkable.  The 40mm is really a JOC/ES 40mm 68 degree SWA that I picked up during the great Meade fire sale around 2013 for $125 new.  I compared it directly against my new 40mm Pentax XW-R, and found that the Meade was slightly sharper at the edge and flatter of field.  However, the Pentax is a bit sharper in the center and has little to no SAEP issues.  It's also so much lighter.  I haven't yet decided which to be on the A-team going forward.

I would like to pick up a Meade 56mm 4000 Plossl smoothie some day.  Bill Paolini liked it better than the Tele Vue 55mm Plossl in his comparison piece 12 years ago.  That, and it is super cool looking to me with its classic lines.  It might be useful in my 127 Mak for exit pupil reasons as well.

5 minutes ago, astrography_MC said:

then why the same 80mm FPL 55 is expensive than FPL 53?

Which two are you referring to?  It could be simple matter that the FPL-53 version is old stock bought at a lower price in the past while the FPL-55 version is new stock bought at higher, pandemic pricing.

44 minutes ago, John said:

I stupidly part-exchanged them at Telescope House for some new Meade SWA 4000 eyepieces (doh ! ) then realised, to late, that the TV plossls were somewhat better optical performers and spent a year or so finding them again on the used market. Lesson learned !

At first I thought you had exchanged them for Meade 4000 Plossl smoothies, which being 5 element, Kowa made, are still sought after today.

5 hours ago, Zermelo said:

I think that's the more damning aspect.  While it may be depressingly predictable that some intern journo with a degree in who-knows-what could produce some nonsense by "taking the complexities out" of something they didn't understand in the first place, there is no real quality control to pick up things like this, because very few people higher up the food chain have any more STEM knowledge than the perpetrator.

I sometimes read the online Daily Mail science feed, because (surprisingly) they seem to tap in to a lot of sources and produce a wide range of content. But the howlers they sometimes make are hilarious, and if I'm interested in a story I have to track down a reliable account.

 

As a computer engineer who has been designing computer chips for everything from mainframes and super computers to GPUs and smartphones over the last 35 years, I've come to realize that the vast, vast majority of the world relies on the expertise of a very tiny number of engineers and scientists to create and maintain modern technology.  To the unwashed masses, today's technology is basically indistinguishable from magic.  What's really scary is that vanishingly few engineers and scientists venture into the political realm, meaning that those in governmental positions are of limited technological understanding and set technology policies by which everyone else must live based on this limited understanding.

FPL-55 is a newer, supposedly easier to work with glass than FPL-53 while maintaining a nearly identical Abbe number, 94.66 (FPL-55) vs 94.93 (FPL-53).  Both are way ahead of FPL-51 (81.54).  Either FPL-53 or FPL-55 will probably work equally well.

5 hours ago, jetstream said:

I  use the Paracorr II that will work with just about any eyepiece regardless of focus position.Had a great chat with senior Mr Nagler years ago who told me how to do it and I developed a lot of respect for him and Televue out of that conversation.

I also went down the path some are considering and figuring out, in this thread- and thankfully I saved up for the PCII and purchased one.

Do you have any issues with vignetting of some 2" eyepieces in your PCII?  I've read some reports that certain eyepieces don't play well with it.