Louis D

Try loosening all the primary collimation screws equal amounts to let the primary move forward toward the secondary until the Barlow reaches focus again.  Then, tweak the primary's collimation back to where it was before, only this time further upward in the tube.

5 hours ago, badhex said:

I can't seem to find it in stock anywhere,

Look over the pond.  Agena has it as GSO, High Point has it as Apertura, and OPT has it as TPO, and all have it in stock.  I have no idea what's going on with UK retailers and GSO products.

It's not perfect to the edge, but it is very good and has enough eye relief to use comfortably with eyeglasses.

If you have a two inch focuser, I much prefer the Omegon Redline 22mm and their kin (I have the Astro-Tech AF70 version) at that focal length range.  I'm not sure how much better either is than your Baader Hyperion 21mm, though.  I've never looked through any BH.

I eventually found an affordable used Nagler T4 22mm and use it preferentially in that focal length range now.  It's close to perfect to the edge with very mild field curvature, astigmatism, and SAEP.

I guess I would ask what it is about your BH 21mm that makes you want to swap it out for a different eyepiece.

Check this post of mine for comparison images through my eyepieces.  The 22mm to 24mm ranges (two separate groups) are toward the lower middle of that post and will give you some idea of how each performs at f/6 relative to each other:

The APM UFF 24, AT AF70 22mm, and NT4 22mm are all in there.

Ernest tested both, and seems to think they're the same optically.  They test pretty much the same and measure pretty much the same.

Celestron X-Cel LX 9mm

Meade 5000 HD-60 9mm

My take on the entire Meade HD-60 line:

I have had the original Vixen LV 9mm for 25 years.  It is sharp edge to edge, but it views a bit dark for its focal length and views rather Plossl-like at 50° AFOV.  Some folks have attributed this darkening to its use of Lanthanum glass.  It is very easy to hold the view even with eyeglasses.  However, I've retired it in favor a 9mm Morpheus and 10mm Delos.  I much prefer their wider apparent field of views and "brighter" views.  Both are easily as sharp if not sharper than the Vixen LV.

The Meade HD-60 9mm is also an excellent eyepiece just a step behind the 9mm Morpheus and significantly wider in AFOV (measured at 62° by me) than the LV (measured at 48° by me).  If you're using a tracking mount, the difference may not matter all that much to you.

1 hour ago, Captain Scarlet said:

Having set it up, and extended the dew shield out to full length, this is what it looks like. Even I am drooling.

 

Scope aside, that's a gorgeous view out your windows.

6 hours ago, Franklin said:

I thought you were supposed to cool scopes down?

Not in Texas in the summer.  It is about 75° F in my house thanks to A/C, and it can be 95° F or more outside after sunset.  I often have to let my scope(s) warm up rather than cool down to acclimate.  On some nights, it never gets below about 80° F before sunrise, so it's never as cool outside as inside.  Believe me, warming up causes just as many optical issues as cooling down.

I wear a pair of distance-only eyeglasses at the eyepiece to correct my 2 diopters of astigmatism.  I bought them online for about $20.  Make sure to get the lowest index plastic lenses to minimize chromatic aberrations at the edge when looking off axis through them with wide field eyepieces.

If you don't need long eye relief, the new Svbony 3-8mm zoom eyepiece is excellent from 5-8mm and very good from 3-5mm.

However, I'd start with a decent mid-power wide field in the 12mm to 16mm range.  There are a lot of good options depending on your budget.

Was this windstorm beyond anything anyone could have anticipated like a strong tornado or hurricane of epic proportions?  If not, the neighbor should be held legally responsible for not adequately securing their car port against typical weather forces for the area.

33 minutes ago, Don Pensack said:

You might also try the BST Planetary eyepieces (they are identified by a 58° rating).

They are sold under at least 8 brand names.

And they all have roll-up eyecups.

And they come in 6mm, 7mm, 9mm sizes.

Here is one of those brands:

https://www.firstlightoptics.com/skywatcher-eyepieces/skywatcher-uwa-planetary-eyepieces.html

I was going to suggest that as well.  However, FLO is sold out of them right now.

I bought the 2.5mm version direct from China for about $35 shipped a few months back.  It is quite good, especially when you figure in the cost.

Check on ebay UK for sellers that have the focal lengths you want in stock.  I'd stick with the ones with the shiny metal bands on the twist up cup.  That's the version I have.  The Skywatcher version seems to come from another factory.

Here's a write-up of four versions of the 4mm focal length Planetary 58 eyepiece:

1 hour ago, badhex said:

Second reason is that I've never got on with the BST 3.2mm in my two main use scopes (ZS73 F5.9 and TS102 F7) for some reason, but that's possibly just personal preference. 

Experienced observer Jon Isaacs over on CN also has issues with the 3.2mm BST off axis.  He prefers the 5mm BST Barlowed.  The 3.2mm Paradigm (BST Starguider) is the only one I don't have and have never looked through, but the 5mm that I do have is quite good.

If you've got the budget, the 3.5mm Pentax XW is basically flawless.  However, it's a rare night even here in Texas that it shows any more detail on an object than my 5.2mm Pentax XL, so I don't tend to use it much.  Perhaps if I had an f/4 Dob it might see more use.

3 hours ago, Captain Scarlet said:

Thanks Dave, the OTA weighs around 9.5kg apparently but it feels heavier. I’ll try to weigh it today, fog still persists so I have nothing better to with it! I have a Skytee2/Uni which will be fine for the load but only has a vixen dovetail. So I’ll probably only mount it on my az-eq6.

Just be cautious of overloading your Skytee 2.  The late @johninderby had his snap off under load, but was able to grab his OTA before it hit the ground:

The mount is made of cast pot metal rather than being CNC machined from a solid billet of aluminum.

On 09/02/2023 at 11:43, Captain Scarlet said:

- VAT (locally 23% on the order value INCLUDING SHIPPING). This simply replaced the subtracted Sales Tax.

No, not even remotely close.  The highest sales tax anywhere in the US is 13.725% in one municipality.  The average across all states, however, is 5%.  Four states have no sales tax at all.  You paid 4.6 times as much in VAT as the average American pays in sales tax.  Most states don't tax food and medicine, either.

3 hours ago, Ratlet said:

I'm really enjoying this.  It's interesting to see empirical analysis of the filter combined with testing at the eyepiece.

Not sure how you manage to change filters so much without getting finger prints on them.  I struggle at the best of times (to the point I designed special filter cases).

Thanks for the feedback.  I'm an engineer who enjoys finding solutions to problems.  The problem here is how to get the best performance out of fast achromatic refractors.  There have been expensive solutions in the past (the Aries Chromacor), but I was intrigued by the possibility of simply improving rather than correcting the view.

I've been using my retired 14mm Pentax XL in a Parks GS 2x shorty Barlow for the testing at about 57x.  I place the object slightly off center to allow for more drift time on my undriven alt-az mount.  I then grab two filters, one in each hand, carefully by their edges (they're all in a shallow box nearby to avoid them disappearing into the lawn).  Next, I return to the eyepiece and move each eyepiece in and out of the exiting light cone using a variation on the blink comparator method to look for changes.  I sometimes move one, then the other, then both at the same time, into the light cone.  I even alternate which one is stationary while moving the other one in and out to observe what changes occur when stacking to better understand what each filter is doing.  This method only works with small objects like planets and stars since I can only see a small portion of the FOV while pulled back so far from the eyepiece to fit one, and sometimes two, filters in between my eye and the eyepiece.

I chose the Pentax XL because it has a smooth top with a rubber guard, so I wouldn't have snagging issues or eye lens scratching issues.  It also has no chromatic aberration issues of its own, so I wouldn't have to sort eyepiece chromatism from scope chromatism.  Lastly, since it was retired by my 14mm Morpheus, I wouldn't be too upset if something were to happen to it.

Grabbing the filters without putting fingerprints on them is difficult, but practice makes perfect.

Overall, I've been really surprised and enlightened by my discoveries.  I can't recall anyone else systematically comparing various filters on an achromat to narrow in on what works well and what doesn't.  There's been lots of work done in the area of figuring out which filters work best on which objects, but they always seem to assume the scope doesn't have strong chromatism of its own to sort through as well.

Often, folks write off fast achromats for planetary usage, but I've found that with the proper filtering, they can put up quite sharp and pleasing images if you can ignore the color cast.

Surprisingly, I've found my brain performs a white balance on pale yellow and yellow-green images over time such that they seem color cast free.

There's also the fun of playing with my toys in a new way.  As a kid, I used to combine my toys in new and unusual ways such as racing my Hot Wheels cars down tracks through long Lincoln Log cabins built over the track.  I was amused by the change in sound as they went through the cabin and how they disappeared and reappeared.  So, I'm always looking for new ways to combine things in ways that haven't been done before.

I spent some time last night observing Venus, Jupiter, and Orion and vicinity with my ST80 and various filters.  Here are my observations:

1. The IR filter did nothing to remove red fringing or sharpen the image.  It must have been the significant IR from the sun being filtered that sharpened my white light solar observing earlier in the day.
2. The sharpest views of Jupiter's bands and of Venus were with the Meade Green inteference filter.  The Cheap Green filter was a bit behind because of light attenuation, but was a good, less expensive option.  Both gave bright stars and star clusters a strong green color cast while allowing for pinpoint focus.  Both made the Orion Nebula invisible.
3. The #12 Yellow gave a sharper view of Jupiter's bands than the light #12A Light Yellow.  Both cut out all violet fringing.  The red fringing was more pronounced than with the #12A Light Yellow, perhaps because there was no blue left in the #12 to counteract it.
4. The #12A Light Yellow didn't really cause any noticeable color cast while cutting out all violet.  However, significant red fringing remained that ruined sharp focus.
5. The Cheap Yellow filter gave nearly identical results to the #12A except with a bit more scatter on Venus.
6. The #11 Light Green (Yellow-Green) filter didn't do a whole lot to block violet or red fringing.  On the violet end, it was similar to a #8 Yellow or Minus Violet filter.  On the red end, it did help to attenuate the red fringes a bit, but not completely.
7. Combining the #12A Light Yellow and #11 Light Green creates a near perfect way to cut violet and diminish red fringing on dimmer objects without introducing much of a color cast or losing much light.  When used on Orion, the nebula stood out a bit better and stars were more pinpoint with almost no color cast.  Venus and Jupiter still had way too much red fringing to be a useful combination on them.
8. The R89 Moss Green filter completely eliminated all violet and red fringing while maintaining a brighter image than the Cheap Green filter, but it was dimmer than the Meade Green interference filter.  Contrast on Jupiter was lower making the bands more difficult to make out for some reason.  Venus showed as a sharp disk.  I'll have to pair it with a variable polarizer to see if Jupiter was simply too bright.
9. The Orion Nebula stood out better with the Moss Green filter than with the #12A-#11 combination by darkening the sky more by attenuating some yellow and orange-red light and cutting all red light without cutting H-B or O-III bands.  The view was actually similar to the Svbony UHC but more pleasing because more stars were visible and more natural looking giving a better context.  The green cast was barely perceptible.  Star clusters around Orion were much more sharply focused by eliminating the unfocused violet and red light.  Bright stars were nearly pinpoint while having only a slight yellow-green cast.
10. The narrowband filters were really only useful on the Orion Nebula.  They didn't really do much useful for Jupiter or Venus.
11. The M&SG filter improved the visibility of the Orion Nebula slightly by cutting yellow and orange-red light which darkened the sky background of some light pollution.  It wasn't very useful on Venus or Jupiter without adding the #12A or #12 filters to cut violet fringing.  There was still plenty of red fringing ruining best focus.

18 hours ago, Don Pensack said:

And the adapter had to support the eyepieces that had a combination 1.25" and 2" skirt

Once again they are haunted by that bad design (hybrid skirts) from way back when.  The screw-on/off 2" adapter paradigm works much better.  It's a shame Al didn't go with that approach when he was starting out.

8 minutes ago, Don Pensack said:

One industry person mentioned several years ago that Meade had had at least 6 different manufacturers make these, and possibly more.

28 minutes ago, PeterC65 said:

I only need glasses for reading but I can sense my eye's are aging when I try to see detail, even in bright daylight. At the last optician visit the astigmatism part of my prescription was -0.25 which is quite good as far as I understand?

0.25 diopters of astigmatism might cause some of the sparkle you saw on axis.  Try looking at stars naked eye and see if they also sparkle similarly.  Overall, that is a very low level of astigmatism.

29 minutes ago, PeterC65 said:

This may be a daft question but do people treat observing as they do reading, so use reading glasses if they need them when reading a book?

I use distance-only single vision glasses when observing.  That keeps the focus plane close to the eyepiece design focus plane so the field stop should be sharp.  It also makes looking up to the sky for object acquisition easier.

I could see using readers if you were referencing a detailed star chart when trying to locate Pluto or an asteroid, though.  That way, you could go back and forth quickly without any fussing putting glasses on and taking them off again.

I just got in from trying various filters for white light solar observing with my ST80 and Baader Solar Film.  My ST80 would not come to focus with my 1.25" Hercules solar wedge, so I had to use the BSF.

First, just adding an interference type IR blocking filter ahead of the diagonal helped sharpen up the image by filtering out unfocused far red light.  I kept it in place for all testing since it didn't shift color at all.  This effect would probably not be very noticeable at night with scotopic vision, but I might try it with Venus and the moon.

The best filters for getting sharp images in roughly the order of best to just so-so improvement:

1. Meade Green interference
2. Cheap Green
3. Meade Red interference
4. #12 Yellow
5. Svbony UHC
6. Zhumell OIII (that is right shifted to cover C2 lines from comets)
7. R89 Moss Green
8. #12A Light Yellow
9. Cheap Yellow

It became apparent that you want a narrowed (but not necessarily narrowest) passband so best focus can be more easily achieved by filtering unfocused spectrum.

The worst was a cheap magenta that made matters worse by cutting out the well focused green spectrum in the middle leaving the hard to simultaneously focus blue and red ends.  I could not bring the image to a combined best focus.

The orange, red, and blue cheap filters didn't help much either.  They didn't make matters worse, though.

My Lumicon OIII didn't help much despite the Zhumell OIII showing good results.

My collection of narrowband Optica b/c interference colored filters didn't deliver like I'd hoped.  The images were generally sharp in them, but it was quite difficult to hold the eye positioning because getting ever so slightly off axis caused blackouts.  Thus, it was difficult to draw any conclusions about them.  I thought the wider passband of the Meade filters showed details more easily and with the same sharpness.  Based on this, I'm not likely to buy a Baader Solar Continuum filter.

The Meade Blue was poor.  I think this is because it passed all unfocused violet.

Lighter filters like my #12A Light Yellow, Cheap Yellow, #11 Light Green, and R86 Pea Green didn't help much because they passed too much unfocused spectrum at either end.

On the other hand, the #12 Yellow was showing really good detail.  I wondered if pushing to the Cheap Orange would show further improvement; but no, it was actually worse for unknown reasons.  Apparently, there's a Goldilocks region for low pass filters right around the #12's cutoff which is very close to 490nm.

The Zhumell Urban Sky (Moon & Skyglow) filter failed to improve the image to any significant degree, even when combined with the #12A to block unfocused violet.  I didn't think to try it with the #12 Yellow because it was working so well by itself.

The R89 Moss Green caused barely any color shift to yellow-green while noticeably improving sharpness.  I should try combining it with the variable polarizer to cut some of the glare because it is such a light filter.  However, narrowing the passband to purely green with either the Meade or cheap green filters sharpened up the image further.

Overall, a cheap green or #56 Green would probably make for a good filter when white light solar observing in an achromat without a lot of cash outlay.  A #12 Yellow is another good, inexpensive option.

At large exit pupils, make sure you're not seeing eye astigmatism on axis and assigning it to the eyepiece.  With a star on axis, rotate your whole head around to make sure the lines of sparkle don't follow your eye's orientation.

The increase in distortion center to edge can safely be 100% assigned to the eyepiece, though.  What you're describing sounds a lot like a traditional Erfle eyepiece.  It's appalling Baader charges so much for these BHA eyepieces.

To confirm eyepiece astigmatism, rack focus inside and outside of best focus.  The lines should swap between radial and tangential forming a small cross at best focus.  If there is a fan pointing away from the cross toward the edge, that is coma and/or chromatic aberration depending on whether it is gray or rainbow colored.

1 hour ago, paleoc2000 said:

I have read all about manufacture location and number of elements.  My questions boil down to two things.  I have never seen one (including looking at pictures on the internet) that was not all chrome (excluding the black center grip).  On this one, the bottom is chrome but the metal on top is brass instead of chrome.  In fact the 6x26mm finder scope on the telescope is also brass.  The eyepiece also has letters LP which none of my other super plossl have.   What does LP stand for?

 

I have never seen a Meade Super Plossl that looked like that.  Perhaps it was specific to a particular scope or collector's edition?

I have no idea if the Taiwanese ones are inferior.  I know my Sirius Plossls from 1990s Taiwan are inferior to my GSO Plossl from 2010s Taiwan.  I'm guessing optical prowess improved in the intervening two decades.  Likewise, I would infer early 2000s Chinese made would be inferior to 2020s Chinese made.  They have noticeably improved optical and mechanical quality in the last 20 years across many product categories.

7 hours ago, Merlin66 said:

The original design was a five element design said to be based on the mythical Masuyama five element design. These are collectables.

They are marked JAPAN on the barrel, and do NOT have rubber eye caps and were manufactured prior to about 1996 by KOWA.

As long as JAPAN is stamped on the upper black barrel, they had 5 elements.  The last year or so of production added eye cups.

The revised 4 element design has JAPAN stamped on the lower chrome barrel.  They are still very good thanks to superior polish and coatings.

8 hours ago, Merlin66 said:

he rest were made in China and changed back to four element design to save $$$$$ ???? which was pretty "basic"

Production first moved to Taiwan in the mid-90s prior to production moving to China.  All were 4 element designs.  I doubt Taiwan was stamped on the bodies.  I have Sirius Plossls from that mid/late 90s era where the boxes say Taiwan, but the eyepiece barrels themselves are blank.

Before investing in exotic glass like Tak TOEs, I would look into getting an entry level binoviewer and a good quality Barlow to boost power when using 15mm to 25mm eyepiece pairs.  I find I can see far more detail on planets using two eyes instead of one.  It also cuts down on glare because both eyes see the same brightness.

I compared the view of Mars at opposition through my Pentax XW 3.5mm and Pentax XL 5.2mm against my Arcturus BV loaded with a Meade 140 2x Barlow element and 2 Svbony UWA 20mm eyepieces.  It was no contest.  The BV was showing loads of detail while both Pentaxes showed a featureless and overexposed orange disk.