Louis D

Try a SVBONY 68° Ultra Wide Angle 20mm with a decent 3x Barlow to get ~7mm effectively.  It's wide field, great eye relief, and quite sharp in such a slow light cone.  I just completed a pair for binoviewing at 3x with a Meade 140 2x Barlow nosepiece and briefly wrote it up below:

It certainly wouldn't cost much to try out the combination.

On 07/10/2021 at 16:13, Basementboy said:

Any guesses what something like this would be worth today?

Pre-pandemic, they were fetching between $400 and $500 in good condition with everything included on CN classifieds.  I haven't seen too many come up for sale during the pandemic, though.  You could probably add $100 or so today thanks to inflation and lack of new SCT stock.  You could probably take those dollar signs and convert them straight into pound signs since everything US made seems higher in the UK.

About 6 years ago, I was tempted to buy a local 10" Meade LX200 for $400 off of Craigslist.  However, it being driven by ancient electronics put me off of it.  That, and it's sheer weight and bulk.  Your model uses a much simpler motor drive, so there is less to go wrong with it over the years.  They were packaged with pretty nice mounts by today's standards back in those days.

1 hour ago, Cosmic Geoff said:

If you just want to look at Jupiter you can simplify things by using the Solar System Align with Jupiter as the target aligning object. 

I could see that being useful for the OP based on living near NYC years ago.  You literally can't see most stars on most clear nights to align on if you wanted to.  The moon and brightest planets are about all that you can see without magnification.  When I moved to Texas nearly 30 years ago, I was amazed to see a plethora of stars again as from my childhood days growing up in the upper Midwest.  That's when I decided to get into amateur astronomy.

24 minutes ago, Roog said:

That looks nice Dave, is it stable enough to keep it sitting on its wheels when observing, or do you lift it off at its desination?

You could always add corner jacks to stabilize it:

Check with @Piero who uses a series of removable ramps to get his 16" Dob out the door with wheelbarrow handles on the rocker box:

As a practicing design engineer, the fact that it locks up at all with any customers says to me it has an unresolved design flaw.  I'll wait on getting one until Baader releases an official fix for them or announces a recall.

Before spending big bucks on a single 7mm eyepiece for cyclops viewing, consider spending a similar amount for entry level binoviewers and a pair of 15mm to 20mm plossls or simple wide fields.  Put a 2x Barlow or just the optics element ahead of the binoviewer to reach focus in most scopes, and you should be at about 3x.  This yields somewhere between 5mm and 7mm effective focal length for those low cost eyepieces.  I find I get much better views with two eyes and simple eyepieces than with one eye on the planets, and I've compared using XWs, Delos, and Morpheus eyepieces.

Keep working on your abstract photography technique, it might be worth millions in the NFT art market someday. 😉

For the amount it must cost to throw in that 20mm erecting eyepiece, you'd think they could throw in a decent Plossl or two instead.

But are the waterproof ES eyepieces dishwasher safe? 😁 I can't be bothered with wipes and little bottles of cleaning liquid.  I just want to toss them in with the dirty dishes when they get grimy.

Look!  No grime and no oils.  Never mind the etching, the important thing is, it's squeaky clean! 🤣

1 hour ago, Don Pensack said:

Regular 90° prisms, yes.  Amici prisms, no.

Which is what are found in prism based BVs that we are discussing.

1 minute ago, Don Pensack said:

The APM is a lot better eyepiece than any of the Pentax XLs

That's a pretty broad generalization there.  Do you mean relative to the 21mm, 28mm, and 40mm XLs or relative to all of them down to the 5.2mm XL?

The optical path length through prisms is shorter than through a series of mirrors.

1 hour ago, Don Pensack said:

Louis,

1) No 32mm Plössl has a 52° field--not one.  The average is somewhare in the 45-49.5° range, the latter with a bit more RD.  I've measured several different ones using the flashlight test.

I have seen 52° in shorter focal lengths, though, but a typical range of Plössls will vary from 47-52° across the series.

2) 27.0mm is the average field stop of a full-field 32mm Plössl, which, on a 750mm focal length, yields 2.06°.

 

Great, but I think you're still quibbling over details not particularly relevant to the OP's original question.

I have measured my 32mm Orion Sirius and GSO Super Plossls to have 52° AFOVs each by the flashlight method and 51° and 50° AFOVs by the photographic method, and 49° eAFOV based on measured 27.1mm field stop.  Again, my measurements might be off by about 0.1mm.

It seems folks have been asking about this eyepiece for at least 8 years on both here and on CN, and literally no one has chimed in to offer any sort of report on it.  Is the entire original stock of this eyepiece still sitting on dealer shelves?

The OP could also try @John's trick of using a 7.2mm-21.5mm zoom in a Baader Q-Turret 2.25x barlow to get a higher power range (9.55mm to 3.2mm) on the (relatively) cheap:

5 hours ago, Ian McCallum said:

The $64,000 question!😂 I was looking at the 12" Dob range, but haven't seen what I really want in stock, plus the thought of a really heavy behemoth puts me off, a bit. I know I could build a trolley of some sort to wheel it out, but I don't know if that's the route I want to go.

I can tell you I have a 15" truss Dob that I rarely use since an automotive back injury in 2000 made lifting the 65 pound mirror box a literal pain in the back.  I keep it in hopes I'll someday be able to park it in a garage on a wheeled cart with corner jacks at a dark sky vacation/retirement house.  That way, I only have to lift it once onto the cart.

I'll have to put a dovetail on my 2000-era ST80 and mount it opposite my 72ED on my DSV-2B mount and compare the views on various targets sometime.  The ST80 is limited to 1.25" eyepieces and thus can't accommodate a TSFLAT2 to flatten the field or provide extremely wide field views.  That aside, I'm curious how much purple fringing and spherical aberration intrudes into the view through the ST80 relative to the 72ED.

21 minutes ago, Andrew_B said:

Are the Vixen HR models no longer in production? I can't afford any at the moment, but I've often seen people singing their praises.

Correct.  Discontinued very recently, so you might still find new old stock at some retailers.

Remind us please what you're looking for?  Originally you were asking about refractors and now you've expanded to Maks and 12" Dobs in another thread.  Tell us what you want to see better, and what limits you have as far as budget, weight, storage, and transport.

41 minutes ago, Don Pensack said:

Maximum field of view with 1.25" eyepieces is 27/750 x 57.2958 = 2.06°, not the 2.2° people have mentioned.

Sorry, I just did a quick calculation using the typical 52 degree AFOV of a 32mm Plossl assuming no distortion to get to 2.2°.  However, this is a minor quibble because neither value comes close to matching the typical 5° to 10° TFOV of handheld, 6x to 10x binoculars which the OP was trying to match, assuming TFOV and not AFOV was meant by the OP's phrase "they give a similar field of view".

3 hours ago, Peter Drew said:

Which Dobsonians use MDF?  All my commercial Dobsonians, Orion USA and Skywatcher are chipboard covered with a sort of melamine coating.

When did this changeover from MDF to OSB occur?  20 years ago, MDF was the go-to wood product for Chinese made scope bases, at least as sold in the US.

13 minutes ago, Ian McCallum said:

Does that mean it get's cold quicker?🤔😂

Does Baltic plywood ever get dark enough to use in the summer? 😉

Since it has a 1.25" focuser, you're never going to be able to go wider than about 2.2 degrees when using a 32mm Plossl or similar.  To use either an 82 degree 32mm or a 62 degree 40mm would require a 2" focuser.

How does the Baader Maxbright compare with the Denkmeier Binotron-27?