Louis D

After the US Congress passed the Foreign Account Tax Compliance Act (FACTA) in 2010 requiring foreign banks to report any assets held by Americans in them to the US government, most foreign banks simply refused to open accounts for Americans, so they wouldn't have to deal with the expenses and bureaucracy associated with compliance. This has made it incredibly difficult for Americans to permanently live abroad. Combine that with tax laws that require US income taxes be paid on all income, foreign and domestic, even if you haven't lived in the US for decades, and Americans abroad have been renouncing their US citizenship in droves. Likewise, I foresee many, if not most, EU and non-EU retailers simply refusing to do business with the UK to avoid the hassle and expense of collecting VAT for them. I can't imagine small American retailers wanting to deal with the hassle of VAT. They already have to deal with 50 different state sales taxes along with myriad different local sales taxes.

Look into getting an entry level binoviewer. I find it comfortable to view even the full moon in binovision unfiltered. The discomfort in monovision has something to do with the huge disparity in brightness between the open eye and the closed eye. It's as if the brain's image processing center just can't cope with it.

The primary is about an f/2 concave, thus the very short tube. The secondary is about an f/5 convex, thus the magnification to a combined f/10 system focal ratio. Both mirrors are spherical. To correct spherical aberration, the corrector plate is aspherical. The resultant system also has low astigmatism. An SCT has uncorrected field curvature and coma in its standard commercial form. That's why there are various correctors for them for photography that are placed near the rear port.

I could see how exposing the objective lenses to direct sunlight could help to keep fungus growth at bay.

Besides MA, there are Ramsden, Huygens, and Kellners which are typically lower than Plossls in the pecking order of eyepieces. They're the designs typically packaged with "department store" scopes for $20 to $40 for an entire telescope package. Here's an image showing various simple eyepiece designs and their spot diagrams which show how well they display a star at various points within the field and with different f-ratio scopes. In this next diagram, you can see how as eyepieces get more complex, correction gets better farther and farther off axis. Your Morpheus falls into the more complex, modern design category similar to Nagler or Speers Waler. You will need to click on the image to expand it.

Your situation is similar to mine, except replace my farmland with open seas. If you look to the east, northeast, and southeast, you'll probably be able to pick out fainter objects thanks to less light pollution in that direction. Basically, start observing objects as they rise in the east after sunset. You'll be able to see objects earlier in the season than those like me who have to wait for them to be in my southern skies due to obstructing trees. At that point, they are less than optimally placed for me light pollution wise. If the bright local lights to the east around that open field bother you, you can invest in an observing hood, or simply cover your head with a towel or opaque cloth. Your southern, southwestern, and western skies are probably completely washed out with severe light pollution as mine are. Other than solar system objects and the brightest stars and clusters, there won't be a whole lot to observe in those directions. It looks like you have decently dark skies nearby to the northwest in Northumberland NP and vicinity if you ever decide to observe from a dark sky site.

Simon B on CN received one in 2018 and posted images in this posting. I'm not sure if there are any actual reports of using it in a scope, though.

Wait for Mars to come back around to opposition in 2 years (December 8th, 2022). It looked terrific through my 8" Dob with binoviewers last fall. I could make out lots of light/dark details very much like the below images. It was amazing, but fleetingly quick. Most of the previous recent Mars oppositions were ruined by global dust storms on Mars that obscured all details, so hopefully 2022 will be more like 2020's opposition.

I was using an f/6 AT72ED refractor, so no difference there. I could try my 35mm in my f6.6 APO to see if it makes any difference. Understand, I'm being hypercritical when I'm looking for edge astigmatism. I take as bright a star as I can find, focus it in the center, note the sharpness, move it toward the edge, refocusing it for the edge to eliminate field curvature issues as needed, and then note the sharpness in comparison. I then rack the focus on either side of best focus to look for astigmatism in the form of radial or tangential lines instead of a nice, off center circle. The 30mm APM UFF passes this test without any issues. All that matters is that you really like the eyepiece in your scope, and it works extremely well for your needs. How it performs under test bench conditions is irrelevant. As for your scope, it does indeed appear to be KUO made. As far as factories go, there's a good probability they were made in the same town, but possibly in two separate buildings dedicated to different optics. As companies expand, it's typically easier to build a new building instead of expanding an existing one, so you end up with a collection of buildings on a campus or even spread around town. I just realized they're based in Kunming (hence their name). That was the terminus of "The Hump" US air supply route for the Chinese army of Chiang Kai-shek in WWII. I also used to work for a guy born and raised in Kunming. Really nice fellow.

I rigged up a mount for my phone on my frac and use SkEye to get me in the ballpark of objects without bright stars nearby. From there, I can usually find them in the finder scope.

The retailer may not let you cancel, claiming it has already been shipped and is tied up in customs, continuing the runaround. That's why I suggested going through your CC company. Tell their representative what you've told us, and that you'd like to cancel the order if the retailer cannot provide proof of shipment to the CC company. The retailer should be able to provide the name of their shipping company, tracking number, and the name of their customs broker.

In my OVL Aero ED 35mm, I'd peg it at the outer 25% of the field of view at f/6. Notice in my above image how fuzzy the marks get about 4.5 inches in from the edge? That's 4.5/17=26% from edge to center. I like to tell folks that the central 75% of the field of view is acceptably sharp based on this assessment.

You could always initiate a dispute with your CC company and let them sort it out with the retailer.

As I said, it depends on where you are located. If you're on the edge of an urban center as I am, 6 is probably the value at zenith. Looking away from the urban center will have a better Bortle value. Looking toward it will have a worse Bortle number. As such, choose your targets when they are positioned in the darkest parts of your local sky. If you're in the middle of either an urban center or dark site, then the Bortle value will probably be fairly consistent around the sky, and it won't matter when you observe targets.

Tripod thread standard: 1/4-20, which means ¼", with 20 threads per inch.

In my experience in Bortle 5/6 skies, your sky darkness will be highly dependent upon where the light sources are greatest. My sky facing a city of over one million and a giant freeway interchange is closer to Bortle 8/9. My sky facing open farmland is closer to Bortle 4/5. Only overhead is Bortle 5/6. Local lighting of a field won't impact sky darkness very much unless it's stadium level brightness.

Assuming you only have a 1.25" diagonal, I would recommend buying a 32mm Plossl. The Astro Essentials and Revelation versions are both good and affordable. It will provide the widest true field of view possible in a 1.25" eyepiece. The 24mm end of your zoom is rather narrow, so the 32mm Plossl can help with locating objects and then centering them for the zoom. A good OIII or UHC filter would be my choice for first filter purchase. Astronomik and several others sell reputable versions. Avoid the super cheap ones, they don't work very well in my experience. If you want higher powers with your zoom, most folks here recommend the Baader Q-Barlow 2.25x Barlow as a decent performer for a reasonable price.

It is field flattened with a properly spaced TSFLAT2 ahead of a GSO dielectric diagonal. Notice that the Meade 5000 SWA 40mm had no problem with the field. The AT72ED has a 430mm focal length and 143mm RoC. Your ST120 has a 600mm FL and 200mm RoC, so it will be less severe on eyepieces. It might need about 15mm less TSFLAT2 spacing than my AT72ED. However, I've found that the same spacing for my AT72ED works just fine with my TS-Optics Photoline 90mm FPL-53 Triplet APO which has the same FL as the ST120. Shortening it didn't seem to improve things visually.

You would think TS-Optics could have had a production run made for them of the 40mm version since it is the most in demand worldwide. The 35mm is going to struggle a bit at the edges in an ST120. Here's how my 35mm OVL Aero ED looks at f/6 in my AT72ED:

Here's Ernest in Russia's review/test of the 30mm, 35mm, and 40mm versions of these eyepieces under the Levenhuk ED brand. All versions are made by KUO and the 30mm and 40mm were originally designed by Thomas M Back as the TMB Paragon. From his summary chart, the measured field of view is 66 degrees for the 30mm, so just slightly less than the claimed 69 degrees (the top row of the table needs shifted one column right): FL AFOV F4 F4 F4 F10 F10 F10 List of Eyepiece mm °/deg. centre zone edge centre zone edge rest aberrations United Optics, ED 40 64 5 18 25 <5 12 20 Ast.,FC United Optics, ED 35 70 5 20 35 <4 12 20 Ast.,FC United Optics, ED 30 66 5 20 40 <4 11 22 Ast.,FC

There is that I'll agree; but on the upside, it dampens vibrations from your finger touching the focus knob.

Since the OP didn't really specify cost, I took the topic's debate to be between wide field and narrow field eyepieces in general. At the high end, narrow field eyepieces like the ZAOs, TMB monos, TAK TOEs, and Vixen HRs still outperform their similarly or lower priced wide field competitors.

OMG! 😲 32mm of in-focus will be required??? I've only got about 15mm of in-focus left on my Dob with a CC in place. It would be fine in my fracs and Maks, though.

I can't think of any recent US leaders who might fit that definition. 😁

Hot cuppa tea, coffee, hot cocoa, mixed drink???