Louis D

If you're content with a 72 to 76 degree field, the TV Delos and Baader Morpheus might suit you better.  They all have ample eye relief and an easy to take in view.

In my experience, viewing comfort equates to eye relief.  If you have to cram your eye into a recessed eye cup to take in the view, how can you relax?

The Ethos all advertise 15mm of eye relief, but due to ergonomic factors, it's probably closer to 12mm to 13mm.  Most folks find them comfortable to use without eyeglasses, but the view isn't as readily accessible as longer eye relief eyepieces.

The ES-92 eyepieces have 20mm of advertised eye relief, but I've measured them at 17mm of usable eye relief.  This is just enough to use them comfortably with eyeglasses.  Many folks find it too much without eyeglasses, but others find the view more accessible and immersive without eyeglasses than the Ethos due to the longer eye relief.  For me, with eyeglasses, I can take in the whole field at once without having to crane my head to the side.  I've overhead folks who look into them exclaim "My God, it's full of stars!", and so it is.  The flat, aberration free field also helps to contribute to this experience.

Stick with 8x42 or thereabouts for handheld use.

It will also increase the focal length of your SCT by 3mm for each 1mm of increased optical path length.  This might amount to 150mm or so moving from a 1.25" to 2" diagonal and visual back.  It will also slightly increase spherical aberration by moving the focal point off the design focal length.

Given the large increases in Skywatcher prices for equipment that does come in, that's a great deal.

The SARD Mark 43 6x42mm binoculars are well regarded for long eye relief and wide field views.

8 hours ago, Spile said:

I did consider a good budget zoom eyepiece like the Celestron 8-24mm eyepiece. At twice the cost, the Baader Hyperion IV zoom and Barlow combo is not a budget option

The Celestron zoom is $90 in the US while the BHZ is $290 and the matching Barlow is $120.  I see they are sold as a combo for $389 here.  That's roughly 4x as expensive in the US.

9 minutes ago, michael.h.f.wilkinson said:

The Vixen Ascot 10x50 ZCF Super Wide sport an even more impressive 8.5° true FOV or 85° AFOV, but with just 7 mm eye relief.

https://global.vixen.co.jp/en/product/1552_00/

These seem to be discontinued.

Spin it as far as possible in each direction and note when the star spots are at minimum size.  That is the point of best focus even if the stars are not pinpoints.

Seagull shapes are generally indicative of astigmatism rather than being out of focus.  If you have astigmatism in your eyes, you may also be seeing it if you're not wearing eyeglasses while focusing.  Try focusing with and without eyeglasses in that case.

It can also massively improve image quality by masking off the objective's edges where figuring errors most often occur.

For cheap, get a 15x70 with 65 degree apparent field and about 17mm of eye relief.  They yield about a 4 degree TFOV.  They're fairly light and handy for grabbing quick higher powered views.  I use them both for astronomy and terrestrial targets.

I've got a few vintage 10 and 11 degree AFOV 7x35mm binoculars.  Amazing views, but almost negative eye relief.  They used aspheric lensed eyepieces to achieve really decent edge performance.

Why ultrawide binoculars in the first place?  You could try binoviewers on a refractor or even a binoscope as alternatives.

Merging images in higher powered eyepieces can be problematic for some people, so keep that in mind.

If 1.25" eyepieces fit, Agena Astro has GSO Plossls in stock which are of very good quality.  A 32mm and a 9mm would be a good start.

8 hours ago, Deadlake said:

Given the cost of TeleVue, which ones would you buy and which ones would you buy another brand as you don't use them enough?

My 22mm Nagler T4 is the only Tele Vue I've kept in my A-team case because there's no good alternative to it for 82+ degree field and long eye relief at the focal length.

My father was disabled, but we bonded just fine in Iowa over the years gardening on our acreage, tending to our orchard, maintaining power equipment, and attending county and state fairs, antique tractor shows, etc.  Just include your son in all of your interests.  As he matures, treat him as your partner in maintaining your home.  I did a lot of the heavy lifting for my dad as I matured.

You would definitely see an improvement in resolution for planetary observing and a slight improvement for extended objects.  This would be especially true for Synta 127 Maks which only have 118mm of clear aperture while the revised Synta 150 Maks have properly sized primary mirrors to yield a true 150mm of clear aperture.

1 hour ago, starboy71 said:

just what is a safe weight a 2inch ep can reach without upsetting the balance of a dob?

It really depends on the design of the Dob.  It makes a difference how balanced the moment arm is in front of and behind the pivot point.  The more equal they are, the more resistant the design is to imbalance.  It also makes a difference what materials are used for the bearing surface and the load bearing pads.  The more stiction between the two, the more resistant it is to imbalance.

7 hours ago, jetstream said:

The 30mm Pentax XW has a very high reputation.

However, practically every report comparing it side by side with the 30mm APM UFF has declared the latter to be the clear winner.  It's a nearly 20 year newer design with two more lens elements and employs a novel telecompressor stage at the field lens end instead of a telenegative stage.

Here are images capture in daylight clearly showing the better edge correction of the latter:

30mm Pentax XW:

30mm APM UFF:

I bought into the hype of the greatness of the 40mm XW versus the 40mm Meade 5000 SWA and was "gifted" one for Christmas, but I found the latter to be slightly better corrected across the field despite costing me 1/3 as much.  The 2" Pentax XW designs are not the best corrected designs at their respective focal lengths.

59 minutes ago, Deadlake said:

What about the 24 mm ES-82? Avoiding Televue means I could get 3 premium EPs for the price of a Nagler or ethos.

I don't have one and have never looked through one due to the limited eye relief.  The 24mm APM UFF that I do have does have enough eye relief for eyeglass wearers and is reportedly just as well corrected.  Neither is as sharp edge to edge as the 24mm Panoptic reportedly.

Here's a 9 year old article that might be of interest to you, 24-26 mm Eyepiece Comparison, done by Bill Paolini before the existence of the 24mm APM UFF, 25mm BST Starguider, or 25mm Meade HD-60 (all three of which I do have).  Edge to edge sharpness isn't the only metric for determining which eyepiece is best for each object.

I do have the 27mm Panoptic.  It is also tight on usable eye relief for eyeglass wearers, but it is extremely sharp in the central 85% of the field, suffering a tiny bit of field curvature and astigmatism at the edge.  I retired mine in favor of the 30mm APM UFF without regrets.

55 minutes ago, Deadlake said:

Would it make a difference with a 40 mm 1.25” vs a 2” ep?

Definitely.  A 40mm in a 1.25" has about a 43° AFOV vs 70° in a 2" eyepiece.  This equates to an enormous difference in TFOV.  Both will have the same exit pupil, so extended objects and the background sky will appear the same contrast-wise.

30 minutes ago, jetstream said:

ES 30 82mm...

I have one, but I think if buying again it would be the XW30 or 30mmUFF. Just sayin'

I have the 30mm ES-82 and the 30mm APM UFF.  The former has more of a wow factor, but has some issues toward the edge (ring of fire, aka CAEP).  The latter is narrower, but easier to use with eyeglasses, and is basically flawless across the field.

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1 hour ago, johninderby said:

An if I win the lottery scope. 😁😁😁

https://www.widescreen-centre.co.uk/LZOS-304-3600-T.html

But why stop there?

On 12/02/2021 at 18:17, johninderby said:

From what I have read the doublet has advantages such as quicker cool down than the triplet and visually very close in performance but would expect the triplet to have the edge for AP. The triplet would require a stronger  mount.

Think it comes down to how much AP ypu would use it for.

My 90mm FPL-53 triplet takes about 30 minutes to warm up 10 to 20 degrees F when I take it out of my air conditioned house during our hot, Texas summers.  Until then, the star images at high power are all spiky.

I had looked at that 125mm, but decided it would be too heavy for my DSV-2B mount.  It's only rated up to about a 102mm f/7 refractor.  I saw the used 90mm triplet for a good price and jumped on it.