Louis D

14 hours ago, cajen2 said:

It's worth noting that several of the other GSO labelled brands don't necessarily offer all the good accessories like the RACI, though I believe the Orion one is identical.

You are correct.  There are several non-US versions that include a straight through finder instead of the RACI.  However, I have yet to see this version sold in the US.  The Zhumell, Apertura, and Orion Skyline versions are/were all identical to the StellaLyra.  My 6" f/5 GSO Newtonian came with a straight through finder, so it is possible the US may yet see a version of this Dob without the RACI, so buyers should definitely pay attention to the details.

1 hour ago, Artik said:

Generally I suggest to go for a Dob but drop SSE - take other dob without it, keep extra $200 they charge extra for better eyepieces and/or filters or on better scope in first place (better focuser, finder etc)

There is an alternative to SSE that helps you finding objects - but it is free and open-source : AstroHopper - it solves the same problem but little bit differently - instead of plate solving you align on a star or planet close to target you are looking for.Unlike SSE it does require to learn the night sky a little bit. But finally it solves the same problems with almost the same ease.

It is highly popular in my local community so you can see sometimes 1/2 to 1/3 of dob users navigate with AstroHopper.

Disclaimer: I'm the author of this app

How does it differ from SkEye?  Is it possible to tilt the phone for easier reading and still align on objects?  Any plans to add plate solving with the selfie camera to improve accuracy?

If weight is critical, harmonic drives are hard to beat because you can often get away without using counterweights.

37 minutes ago, LaurenceT said:

"trippy view".....love it🤣

No joke.  I'll try to remember to snap a pic through it of Jupiter sometime.

1 hour ago, Don Pensack said:

More of concern is that though they give a 20mm eye relief from the glass, they are stating only a 12mm eye relief from the rubber eyecup, ruling out glasses use.

Missed that.  I'm out unless screwing off the upper ring restores most of that eye relief.  Despite my 40mm XW's eye lens being recessed 7.5mm, I still measure 17mm of usable eye relief rather than the 15mm quoted in the chart up above.  There is a threaded ~6mm tall metal lip above the glass.  I suppose you could machine it off if you didn't want to be able to thread on the eyecup any longer and get to about 22mm of eye relief.  Perhaps something like this could be done with the new XW85s.

1 hour ago, Don Pensack said:

ES told me several years ago that 22mm was the maximum possible focal length for the 92° series, but that they were a bit scared to make it because it would be well over 3 lbs and physically larger than the 17mm.

That seems odd.  They make a 25mm ES-100 (with a touch of vignetting).  It seems like 23mm to 26mm at 92 degree should be doable.

1 hour ago, Highburymark said:

Interesting - I see some colour with the 5mm too, the only XW I own, but not that it would diminish my enjoyment of the eyepiece.

So does my 7mm XW at the edge.  My old 5.2mm XL does not.  I've never detected any aberrations edge to edge in it.

If you need long eye relief, I would steer you toward the 30mm APM UFF or one of its other brandings.  As you say, the 32mm is little better than an Erfle from what what I've read over the years, which is to say pretty bad at f/5.  It boggles the mind retailers ask more than $120 for them based on performance when there are $200 28mm UWAs that trounce it AFOV and correction-wise.

At 22mm, I can highly recommend the Omegon Redline since I've had the Astro-Tech AF70 version for years.  It is nearly perfect to the edge at f/6.  Only the last 5% shows mild astigmatism.  Eye relief is very comfortable, no vignetting, and no SAEP/CAEP.

Wow, that is a loaded, open-ended question.  How much money do you have?  I can point you to many excellent eyepieces ranging from $300 to well over $1000 each.

15 hours ago, Astro_Dad said:

Quite a lot has been written about the relatively new to market Stellalyra series of Dobsonian ‘scopes

New branding perhaps, but these GSO scopes have been available under multiple other brands for years.  I recall the Zhumell ones coming out well over a decade ago.  Here's a 2009 review.

Otherwise, very nice write-up.  I agree about the collimation knobs protruding being a concern.  I have a GSO 6" f/5 OTA with the same issue.  I guess since I've never had a Dob with a navigation knob, I've never missed having one.  I just curl my fingertip around the end of the tube.  Handles, especially two on the base, make moving an assembled solid tube much easier.  I just hug mine to my body, straighten my knees, and off I go with it.

Hopefully edge correction is better than in the 30mm and 40mm XWs.  The 30mm suffers from edge chromatic aberrations and the 40mm from edge astigmatism and field curvature, and they're only 70 degrees.  The 23mm appears to be almost identical in size to the 30mm while the 16.5mm will be a bit taller.

With MSRPs of $479.95 for the 16.5mm and $499.95 for the 23mm, I'd have to think long and hard about buying them since I already have the 17mm ES-92 and 17mm and 22mm Nagler T4s.  What I really want is for ES to release a 23mm to 26mm ES-92.

I'll take a wait and see attitude toward these new XWs for now.

Press release image:

Here's a couple of press releases I found about them.

If that is a 127mm Mak, you could adapt it to use 2" eyepieces to get to a wider field of view.  I did it with mine.  However, why would you want to use a 2x Barlow with a 127 Mak?  It is slow (f/12) and has a long focal length (1500mm).  8mm is about the shortest eyepiece I use with mine.

Probably should just return to seller as "Item misrepresented" or work directly with them on an exchange with possible credit, making them swallow the additional shipping costs.  Was it this ad?  If so, it was definitely misleading.  It can accept a 1.25" eyepiece with the included adapter, but it is always listed as a 2" Barlow by every dealer I've ever seen.  Here's the same GSO-made Barlow under the Altair brand on the ENS website properly labelled as a 2" Barlow.

You could use it to achieve critical focus visually, I suppose.  You would then remove it to observe and resist the temptation to tweak the focus.

There is an apodizing mask you can make from window screen material and crafting foam board to supposedly improve planetary views.  I made one back in the late 90s and get it out sometimes to see if it helps.  My impression of it is that it makes very little difference in contrast or sharpness.  However, it makes for a really trippy view with lots of diffraction effects going on everywhere outside of the center.

On 26/10/2022 at 11:12, Jimbo64 said:

I'm thinking similarly of what to get to replace my wonky 8" dob (see: https://stargazerslounge.com/topic/401726-what-eaa-set-up-would-you-choose-if-you-had-to-start-again-from-scratch/), but when I think of opting for the EQ5 the difference in price/ payload to the HEQ5 makes me think that's a better value and future-proof option. 

But then again, reviewing the HEQ5 and EQ6-R-pro takes me down the spiral of justifying ever increasing spend. I blame the hobby!

The sheer weight of these EQ mounts puts me off immediately.  My wonky back makes dealing with the heavy head, legs, and counterweights a literal pain in the back.

9 hours ago, oriswinter said:

If its too small when properly in focus then you may need a 2x barlow, or an eyepiece with higher magnification, if you cant see the rings with your eyes then you definiently wont be able to see it in a photo using a phone

If you can see the rings of Jupiter from Earth with any telescope, you'll be miles ahead of pretty much any ground based scopes.  They weren't even discovered until 1979 when the Voyager 1 spacecraft passed by Jupiter.

25 minutes ago, Sirbananad said:

Is there a way to fix optical train or?

Sure, buy a bigger scope and observe from more stable skies if you want to get more magnification and thus more detail.  A short f-ratio 102mm achromat is never going to show you Jupiter in lots of detail.  Even a with a 102mm APO, it takes time to pick out subtle details in the bands.

With a suitable eyepiece though, you should be able to see at least one band on Jupiter with that scope.  I've done it with both one of those 76mm f/4 Newtonians with a spherical primary mirror and a Plossl eyepiece (though I don't recall the focal length of it) and with a short tube 80mm achromat with a Plossl eyepiece, so your 102mm achromat should be able to manage it.  I suspect your 10mm eyepiece is the weakest link and needs upgraded.

A quick fix your scope's chromatic aberration would be to get a 1.25" Yellow #8 filter to cut out the violet-blue fringing.  If that doesn't help, try a 1.25" light green #56 filter to cut out both the blue and red ends of the spectrum.

The TS-Optics version of the AT72EDII, the TS-Optics Doublet SD Apo 72 mm f/6 - FPL53, recommends the TSFLAT72.

Toric lenses work for some folks, but not others, for astronomy observing.  They are weighted at the bottom by making them thicker so they will rotate to the correct position for astigmatism correction when looking horizontally.  The problem arises when looking mostly downward into an eyepiece.  The contact lens will then start to rotate out of best correction position for some people because gravity is acting on the lens as a whole to pull it off of the eye.

I haven't tried contacts at all, myself.  I get pinkeye infections far too easily without them whenever I get a head cold.

I generally don't insert Barlows all the way into the focuser to avoid racking the focuser out so much.  Of course, this assumes the Barlow is long enough to allow this to work.

Focal extenders are just the opposite.  They need lots of in-focus to work.  As such, many focusers can't be racked in far enough to reach focus with them.

3 hours ago, JeremyS said:

I’ve always found my Pentax XL 5.2 a super eyepiece with my FS 102, @Louis D. But I rarely use it these days. I should do.
Maybe we could generate a cult following of the XL 5.2 🤔

I know 25585 (Richard?) really likes his as well.  He's only active over on CN now.

I finally compared my new 2.5mm TMB Planetary clone to my 3.5mm Pentax XW and 2x Barlowed 5.2mm Pentax XL on the moon last weekend.  I used my sharpest Barlow, a 1990s 1.25" Orion Deluxe 2x from Japan in my 6" f/5 Newtonian.  It's about 6 inches long, so it very gently diverges the light cone limiting aberrations.  That, and it has at least one baffle to limit stray light.

Sorry, I forgot to mention I was using a new to me GSO 6" f/5 Newtonian with their dual speed focuser.  It was mounted on my DSV-2B.  I kept the coma corrector out of the optical train to limit introduced spherical aberration on axis.

The views were probably best with the 5.2mm XL by itself, followed by the 3.5mm XW just due to the ever tinier exit pupils involved.  However, at about 2.5mm, the Barlowed Pentax XL was a bit sharper and contrastier, but not by much.  The bigger difference was the 5.2mm XL's wider AFOV and much longer eye relief that made using it even without eyeglasses much more enjoyable and relaxing than using the TMB clone.  Of course, the Barlowed XL was way fatter, longer, heavier, and more expensive than the TMB clone.

For the money, the 2.5mm TMB is a really good deal for a rarely used focal length.  I seriously doubt I'll use it much going forward, but it made for an interesting learning experience.  It reinforced my view that 1mm is about the smallest exit pupil I can comfortably use for any significant length of time.

Tried it out this weekend splayed out almost to the max so I could sit in a stackable patio chair while viewing through the eyepiece of my GSO 6" f/5 Newtonian on my DSV-2B mount.  It worked great.  I did have to put vibration suppression pads under each foot; but once I did, it was rock solid with no vibrations at all.

If you look for used Bogen 3051/3251 or 3033/3036 tripods, you can save a bundle.  I picked up a used 3033 for my daughter's camping kit off of ebay for $75 in absolutely new condition 3 years ago.  It had been used to shoot a corporate video years ago, and then was stored and forgotten for over a couple of decades.

1 hour ago, Ricochet said:

The downside of the lightness is that there's not a lot of weight in the objective to counterbalance the eyepiece/diagonal and so it tends to be quite back heavy.

Same thing with the AT72ED.  I mounted an 8" dovetail bar to the mounting foot.  To reach balance with 2" eyepieces requires clamping the bar just about even with the focuser knobs.

1 hour ago, Stu1smartcookie said:

But the Evo  72ED is very well priced and gives very clear views ,  and sits very well on a photo tripod or star tracker . For a quick G&G its a great buy . 

Not so much in the US.  Without sales tax, the SW 72ED ranges in price from $400 to $540 while the Astro-Tech AT72EDII FPL-53 is $489.

For comparison, the Astro-Tech AT70ED is $329.  It is the closest successor to my AT72ED.  The TS-Optics 70 mm F6 ED is identical and priced at €318.49 excluding VAT.  Both brandings have an R&P focuser.