Louis D

I find my 3.5mm XW to be every bit as sharp and easy to use across the field as my 5.2mm XL. I'm not as fond of my 7mm XW which exhibits a bit of edge issues on bright stars. I also really liked my 14mm XL for years until my aging eyes could no longer accommodate its field curvature. I ended up swapping it for a 14mm Morpheus. Similar field curvature, but quite a bit wider (78 vs. 65 degrees), so the field curvature tends to start further out. However, I find myself using my 12mm ES-92 more often than either 14mm. It is phenomenal in every respect. Enjoy using your new to you 3.5mm XW.

Like anything, it depends on what you're comparing it to. Is the BHZ better than Pentax XWs and Delos or Ethos eyepieces, no. Is it better than Kellners and Huygens, yes. Is it better than Plossls? That depends on which Plossl you're comparing to. A lot of folks like their Leica ASPH zooms enough to sell their XWs and Delos eyepieces making the economics work out. And no fixed focal length eyepiece can be nearly instantly adjusted to match its focal length to the current seeing conditions like a zoom can.

I use the nose piece of a 1990s vintage, Meade Series 4000 140 APO 2x Barlow screwed into the nose piece of my Arcturus binoviewer (same as the Revelation) to reach focus in my Newt. It works out to yield 3x magnification, which isn't bad considering the Barlow alone yields 2.4x rather than 2x. The field of view is sharp and color free from edge to edge, but wide fields of view are not possible with this setup. These Barlows come up used for $40 or so on this side of the pond quite regularly. Not all Barlow nose pieces are removable, and not all that do are 1.25" filter threaded. For example, the Tele Vue 1.25" 2x Barlow is threaded smaller and thus won't grab 1.25" female filter threads. To achieve wide fields of view, I added a 0.5x 1.25" focal reducer and 45mm of 1.25" spacer tubes between the binoviewer and the Barlow nose piece to reduce the magnification of the Barlow and make a home brew OCS/OCA/GPC since I had all the parts anyway. However, this results in massive field curvature, so it's not at all a perfect solution. However, scanning rich star fields with two eyes with such a setup is still gratifying if you focus your attention strictly on the center of the field. It's just not useful for critical observing edge to edge.

APM Ultra Flat Field 30mm if 72 degrees is wide enough for you. I find it sharper and color free edge to edge than the ES-82 30mm.

Have you removed the polarizer when viewing the moon? The beam splitter and the polarized light from the polarizer are not going to play nice together because the beam splitter will probably partially polarize the light as well. I find I don't need to dim the moon when using both eyes. It's no different than looking up at the moon with both eyes.

I'm guessing you don't have little kids and pets that tend to accidentally knock things over or otherwise damage things. All of my astro gear sheltered in the backs of a couple of coat closets to protect them during my child rearing years. Even though I'm an empty nester now, I continue to store them there out of habit.

Not just A forum, this forum. Exactly what forum does this other retailer support? If it was an argument between FLO and Astronomics (CN sponsor), I'd have to agree with you. Do you know for a fact that @Harry85 has been helping SGL's sponsor recently? This is exactly how manufacturing moved to China, to save a few bucks per item.

Why not support FLO, our sponsor, by buying from them? They give a 10% discount on 2, 15% discount on 4, and 20% discount on 7. How is skies_unlimited's 5% discount better?

What about an observatory with remote sensing so you can program it up to do an imaging run if the sky conditions warrant it and close up automatically if they deteriorate?

Interesting. In the US, Sky-Watcher founded Sky-Watcher USA to be their importer/distributor rather than rely on a third party. Since Orion USA also imports some Synta products branded as Orion, I wonder how they interact here in the US.

Being the brightest nebula in the sky from our perspective, it's pretty easy to see in just about anything. However, late May is not the right time of the year to view it. If anything, adding an OIII nebula filter can help bring out the fainter details in light polluted skies once winter rolls around again.

Definitely by 200x M13 starts to resolve in an 8", not sure about a 6", in Texas seeing conditions.

You may have the more desirable Japanese made version. Check the eyepiece and/or box. If so, they go for $100+ on the used market in the US, so price accordingly if you ever plan to sell it. The Japanese one looks like the following, note the step in the eye cup: The newer Chinese one has a straight sided eyecup; the same diameter as the upper barrel:

Which ones? The Meade 8-24 is $64 at OPT while the Starguiders are $60 at Agena Astro. Pretty much the same price.

Cost and level of correction. Since there are no regulations on minimum acceptable levels of optical correction and mechanical refinement for astronomical telescopes and mounts, manufacturers make everything from $25 toy telescopes with terrible optics and mechanics to multi-hundred thousand dollar scopes with excellent correction and superb mechanics. Imagine if there were no street regulations on cars. Manufacturers would be putting out dune-buggy type kits for street use powered by lawn mower engines side by side with luxury cars: vs. Just as you can't make a Bugatti for the cost of a go kart, you can't make a 12" APO for the cost of a 50mm department store telescope.

Pretty much validates what I said about negative-positive designs not matching a purely positive design. Of that list, only the 40mm ES-68 is a purely positive design. I have the 40mm Meade 5000 SWA version of it, and it's not as sharp in the center as the even simpler 40mm Meade 5000 Plossl which is very sharp only in the inner 30 degrees. Another example is my 30mm Agena UWA 80 degree Wide Scan clone that is sharper in the center than my 30mm ES-82. However, it has field curvature and astigmatism outside the inner 40 degrees.

Besides a solar filter, the only other filter I use regularly is a 90s vintage Lumicon OIII filter. It can make all but invisible nebula obvious by blocking all light except a narrow notch around the OIII emission lines. Even though this image compares two OIII filters, one with a four times wider passband than the other, it demonstrates the difference I see between unfiltered and filtered views visually:

You could also get a diagonal with a helical focuser for fine focus.

Yes, you've basically derived why fast-ish ED and APO refractors are popular, and why big Dobs have gotten progressively faster and thus squatter. It also accounts for the popularity of specialty, short focal length eyepieces like the Vixen HRs and Tak TOEs to achieve high magnifications and small exit pupils while maintaining ease of use and high image quality.

There's plenty to be seen in a 6" telescope such as yours. As @Dr Strange suggests above, there's the Messier catalog for starters. There's also the Caldwell catalog which was compiled by Sir Patrick Alfred Caldwell-Moore for amateur astronomers to highlight many showpiece objects not listed in the Messier catalog.

I was thinking more in terms of 80+ degree designs that seem to sacrifice central sharpness for overall correction. There are simple UWA eyepieces out there without a negative group that appear sharper in the center than negative/positive designs such as Naglers and ES-92s. Their downfall is outside that central 30 to 40 degrees of ultra-crispness. The Delites are generally judged to be slightly behind the simpler, positive only designs like the ZAOs, TOEs, XOs, HRs, etc. in terms of contrast, but perhaps not in sharpness. I would love for a negative/positive design to match those specialist eyepieces for sharpness, contrast, stray light control, etc. and still yield an 80 degree, 20mm eye relief design, but it hasn't happened yet. The designs are getting closer, that's for certain, but there is still a slight gap. My hat's off to Tele Vue for their work toward eyepiece perfection, pushing the industry forward and out of the eyepiece stagnation of the 1970s and earlier. I'm just saying we haven't achieved eyepiece nirvana just yet, despite marketing claims to the contrary (think Nirvana branded eyepieces).

Here's a pretty similar thread from 5 years ago covering your question:

Since you're talking about a 2000mm telescope, you would probably want the longest practical focal length possible to limit magnification to something a bit more manageable. As such, I would probably recommend a 30mm APM Ultra Flat field since it has an M43 thread under the eye cup that can be used to attach a camera to for afocal digiscoping. It would yield 2000/30=67x and project a 70+ degree image into the lens. Obviously, the taking lens must then be a wide angle lens. I have no idea if it would work for eyepiece projection because few visual-only eyepieces project a flat enough field for photography. Afocal projection avoids this because the taking lens of the camera does the flattening for the system. May I ask why you would want to put an eyepiece into the system instead of just using prime focus photography? If you add a focal reducer/corrector, the focal length will drop to about 1260mm, which is much more manageable. Are you planning on doing high frame rate planetary photography at high powers?

I think the appeal of these Masuyamas is that they are ultra fine polished, positive only designs. I've yet to find a negative-positive design that's as sharp in the center as a purely positive only design. Some come close, but they always seem to give up a little bit to a fine positive only design. I guess if you're happy with a very sharp 42° image surrounded by another 21° of lesser sharpness on all sides for context, then these eyepieces might be for you. I would think that a tracking mount would be essential to enjoy these so you wouldn't have to watch your object distort as it made its way across the field of view.

Possibly an aspheric 3 element.