Louis D

You'll get vignetting trying to use a 6.3 FR and a widest field 2" eyepiece at the same time. TANSTAAFL. You can either maximize your TFOV with the 6.3 and a 32mm 1.25" Plossl or via a 40mm SWA like the Pentax XW-R 40mm in a 2" diagonal without FR. If you really want to try combining the FR with a 30mm, 70° eyepiece, I would recommend the 30mm APM UFF or one of the other 5 or 6 rebrandings of it. It has better correction, a flatter field, and is more compact, lighter, and less expensive than the 30mm XW-R. However, you are likely to see some vignetting. You're never going to get decent wide field views even with the 1500mm focal length using the FR. A 72mm ED refractor or similar would nicely complement the 9.25 SCT. You might even be able to mount it as a super finder with the SCT.

There are both variable length extension tubes and tilt adjusters to fine tune each.

The 40XW is nice thanks to its relatively light weight in comparison to the decloaked Meade 40mm 5000 SWA (same optics and weight as 40mm ES-68) or, presumably, the 41mm Panoptic which I haven't had a chance to use. I'm not sure it's quite as sharp as the Meade, but it definitely isn't as flat of field. There is a bit of field curvature in the XW, but nothing too distracting. SAEP (kidney beaning) is less in the XW than the Meade, so it is easier to take in the entire FOV, but there is still a bit of blackout here and there. The ergonomic conical top of the XW is very much appreciated compared to the slab top of the Meade which forces me to tilt my head to the side to use it. Eye relief is significantly longer on the Meade, though. I have to touch the top of the XW with my eyeglasses to take in the entire FOV while I can simply hover above the Meade. All in all, it's hard to pick a winner between the two.

Can't you use an EQ mount as an alt-az mount by setting it to 0 or 90 degrees latitude?

I would think if you don't have it exactly level, this top mounted and counterbalanced design would be much more immune to swinging around in azimuth than a side mounted design if unclutched unless it is also counterbalanced.

Swapping out a 40XW isn't much of a challenge at 1.5 pounds to keep a mount from diving in my experience. My 17mm ES-92 at 2.6 pounds is much more of a challenge even for my Dob. Another problem is that tall eyepieces make a mount want to tip backward at high altitudes. I'd be interested in how well this new mount resists turning turtle under such conditions. So this mount doesn't have tension knobs, only locking clutches? I like separate tension and locking controls. Usually, one can't do a good job of both unless it were to have a push-pull locking feature so as not to disturb the tension setting.

Have you tried adding a field flattener to the front of you diagonal? I use a TSFLAT2 with 15mm of spacing in front of my 2" diagonal in my short refractors to do a good job of flattening the curved field. You can tell if field curvature is the issue by focusing a star in the center, and then moving it to the edge, and seeing if it focuses to a tighter pinpoint by refocusing. Most inexpensive short tube refractors have field curvature. The Tele Vue NP101 does not thanks to its Petzval design, though.

Only at high powers on the planets will you notice a purple fringe around an object based my experience with a 72mm f/6 FPL-51 doublet. The rest of time, the additional aperture of the 100 will easily rule the day. I will say the fringing was annoying enough that I popped for a used 90mm f/7 FPL-53 triplet which has little to no discernible color at high powers on planets or the moon. However, my 8" Dob blows it away when it comes to planetary detail. Aperture rules.

I always bring a couple changes of clothing and toiletries in my carry-on because I've had the airlines lose my checked bags for days several times.

Then how about starting with a true carry-on sized rolling case and then adding the foam or dividers to it? It's much less likely to receive unwanted attention in an airport terminal, and it comes with wheels and a handle to make transport easier. Check thrift stores for used ones for cheap. If it's just a small scope, you can probably pack it with your clothes in a regular carry-on since most airlines only allow one per passenger.

I've read of imagers trying get the spacing correct to the 1/2 millimeter. You might also run into tilt issues where different corners are flattened at slightly different distances.

You need to decide up front if you are going to store your eyepieces vertically or horizontally, as that determines how deep of a case you'll need. Check you local big box stores, discount warehouses, and discount tool stores to see what they might have locally. Pistol cases are also handy, but might be more difficult to find outside the US. 😉

I just ordered another 20mm Svbony 68° for $20 to pair up with the one I already have in my binoviewer. I'm curious if they will work better than the 19mm Konig pair I have that appear to be from binoculars. If Svbony stopped them down to 50° as with a Plossl, they'd be really good to the edge. Compare the generic reversed Kellner below which has a measured 50° AFOV with the same inner 50° AFOV of the Svbony directly below it. It's pretty sharp at f/6 over that inner 50°. That, and eye relief would be fantastic for eyeglass wearers compared to a 20mm Plossl. I have no trouble seeing the inner 60° of the Svbony with eyeglasses when just touching the folded down eye cup to my eyeglasses. I can hover and still see the inner 50° with ease.

I'll definitely look into getting some anti-seize compound. I didn't even know it existed. Thread lock, yes. Anti-seize, no. My step rings are always getting locked on each other when attaching auxiliary lenses to camera lenses, and this could be just the thing to make disassembling them when done easier.

Yes, reflections off of glass are polarized. This can be used to the viewer's advantage when using a Herschel wedge for solar viewing. A single polarizer on the end of the eyepiece can provide a good amount of variable dimming just by rotating the eyepiece. With my wedge, I have a variable polarizer that I set to fairly dim for unpolarized light and then rotate the eyepiece with the filter attached to adjust the dimming even further.

You might also want to try an 82A as well for higher powers when the image gets dimmer. It has 73% transmission versus 29% for the 80A. The 82A won't significantly knock down brightness, though.

I would try an 80a filter to knock down the brightness a bit and bring out red features better. It generally makes the GRS pop if in view. Once I switched to binoviewing planets and the full moon, this whole issue went away because both eyes are seeing the same intensity. It's also way more comfortable for extended viewing to pick out find details. Filters don't really help with BVing in my experience.

Yep, field curvature. Put the flattener back in and adjust the spacing if needed to get the best star pinpoints in the corners once focused for the center.

That new OIII doesn't look good. What is meant by Baader when they say "improvement"? Did they ever define what that means in a quantifiable way? Did we ever figure out if these are Chinese made or not?

😱 Rich winter star fields like those found in Orion and Perseus as well as the Pleiades benefit from a wider FoV. There also some along the summer Milky Way to be enjoyed, but they don't pop as well for me because of our continual summer haze due to humidity, forest fire smoke, and Saharan dust. That, and the lack of regular, strong fronts to clear the air. Our summer air stagnates for weeks at a time due to a stationary high pressure dome right over Texas.

A lot of it will depend on the shape of your face. I have deep set eyes with a prominent nose bridge such that I can't fit it between Morpheus width eyepieces (55mm). The 19mm Panoptic would probably not be an issue for me due to its narrower width (43mm) and conical top.

Yes, all the LV, NLV, and SLV eyepieces below 9mm were and still are 45°. The original LV line also had 7mm and 18mm 1.25" versions that were dropped. The 30mm LV 2" was dropped in favor of the 30mm NLVW. The 50mm LV 2" was dropped without a replacement. The 40mm 1.25" carried on into the NLV line but was dropped with the SLV line. The 8-24mm zoom was also dropped with the NLV line. The 9mm LV was my first eyepiece. It is still quite good, right up there with the Pentax XL/XW and Delos lines, just narrower (48° measured via both projection and photography). I just don't get on with its stiff, roll down eye cup. However, it does allow for a full 18mm of measured, usable eye relief that the NLV and SLV eye cups do not. Today, though, I tend to prefer the 9mm Morpheus at this focal due to its much wider field (78°/79° measured via projection/photography), slightly longer usable eye relief (20mm), and just as sharp images for most of my viewing. I'll have to have a shootout between the 9mm Morpheus and LV someday just to confirm. However, all that being said, I find I see more detail on the planets and the moon using binoviewers with adapted microscope eyepieces than monoviewing with any eyepiece. It reduces the appearance of floaters and keeps my eyes from being overwhelmed by the brightness differential between my two eyes in monovision at the opposition of Mars, Jupiter, and Luna. Brightness is not such a big deal on Saturn, Neptune, or Uranus because they are considerably dimmer.

The 19mm Panoptic was designed with BVing in mind. They are compact and light weight. However, eye relief is too short for eyeglass wearers.

I found the BHZ too tight on eye relief for an astigmatic eyeglass user like me. I use a Celestron Regal zoom eyepiece with the adjustable eye cup screwed all the way off to maximize eye relief. They also work well as a pair in a binoviewer. Since I picked them up for $60 apiece, I've been quite happy with them. Since the top doesn't rotate, batwing eye cups are also possible with BVs.

The 20mm APM XWA would probably work well for you except that it isn't in stock anywhere. The 22mm NT4 won't correct for coma. Al is simply stating it is well corrected in an f/5 scope for things such as astigmatism and chromatic aberrations near the edge. The APM XWA won't be too much different. The 24mm APM UFF and 24mm Panoptic wouldn't come close to your goal of (nearly) maximizing true field of view. The 13mm would probably get used the most since it provides a nice (high) mid-power. Instead of a Paracorr II, you could start with a GSO coma corrector (Revelation, Omegon, TPO, Astro Tech, Apertura, etc.) and a 25mm M48 spacer ring between the optical element and the eyepiece holder if your budget is tight. It will correct 90%+ of the coma in that configuration for eyepieces that focus within 5mm of their shoulder.