John

48 minutes ago, Stu said:

I should do a comparison between the Leica and some of my BGOs to test that sort of thing John. I’ve done it for solar and the Leica won, so I would expect it to be pretty good on deep sky too but I haven’t actually done a side by side.

The Horsehead Nebula is a good comparison Stu. With the Baader zoom it was totally impossible to see but with the 10mm XW it was just plain invisible 🤣

I will have to try using my 2.25x Baader barlow with my XW 10mm and find out how it compares with my 5mm XW

I suspect the result will be pretty close as has been said.

I've been screwing the removable lens section of the barlow directly into the barrel of a 4mm HD ortho that I have which gives a 1.3x amplification (3.1mm effective FL approx) and the results have been rather impressive with the bonus of making the short ortho eye relief a bit longer. Good glass in the Baader 2.25x barlow.

13 hours ago, globular said:

Excuse my ignorance but how does poor transmission manifest?
Presumably a dimmer image when compared to another eyepiece at the same magnification?

Is the main cause of transmission loss the surface of lenses?
So the more lens elements an eyepiece has the more prone to transmission loss it is?
And the fight back against this is good quality coatings on the lens surfaces?
And these coatings push up the price?
So a cheaper zoom is more likely to suffer more transmission loss than a more expensive one?
Although this is not the only factor in the pricing of eyepieces so may not always be a reliable indicator of superior quality?

The way that I spotted this was observing galaxies and at that time notably Messier 82 because there was a bright supernova in it and therefore that galaxy got a lot of attention. The Baader zoom showed the galaxy nicely and using the zoom the dark rifts across it and knots within the galaxy became more obvious. All very nice I thought, until I compared the views with the Ethos 8mm and the Pentax XW 10mm. It was then that I noticed that the galaxy appeared both generally brighter and the contrast features more apparent when using the fixed focal length eyepieces. Granted, the Ethos and XW's are much more expensive than the Baader zoom so the zoom was doing quite well. But there was a difference and I found that repeated with other galaxies.

This may well be a feature in other zooms as well. I guess there are bound to be one or two compromises in return for the variable focal length ?

The Baader zoom is a good eyepiece generally and I would probably own one again for outreach and travel and be aware of it's strengths and weaknesses.

I have an excellent quality 5 inch apo refractor but I've not compared it with an 8 inch SCT directly having not owned one of those recently.

Given how the 5 inch compares with my 12 inch dobsonian I would say that the 8 inch SCT should show more resolution of the stars in globular clusters, fainter stars in open clusters, pick up fainter galaxies and show a little more extension in the brighter galaxies, similarly on nebulae. On double stars the overall performance is likely to be similar but the refractor will show tighter star images which may aid splitting close / uneven brightness pairs. On the moon and planets, assuming that the 8 inch SCT is well cooled and collimated, the performance could be quite similar. The refractor might show low contrast features a little more clearly and fine features possibly a little sharper but the conditions will also play a large part in that. With planets in unfavourable positions (ie: low in the sky) the refractor might have the edge.

Obviously these are not detailed descriptions but might give you some idea.

I have yet to use a Delite but the reports I'm reading here and elsewhere seem to be very encouraging indeed. 

I've not used a Morpheus either - I wonder what the 4.5mm is like ?

I've only owned and used one Tak LE and that was the 30mm. It was decent but not really outstanding. The shorter focal length ones might be better ?

5 minutes ago, jetstream said:

I have 3 very good zooms and all excel in sharpness. The one area where they don't compete is in transmission. Tested against some other good eyepieces such as the 10 BCO and Docter UWA, other orthos etc the zooms fall short in the transmission dept. Of course this is to my eyes.

The Nagler 3-6 zoom is a mainstay for the Heritage 130.

Transmission was exactly where the Baader 8-24 that I last owned was a little lacking for me too.

I had the Leica ASPH zoom and the Baader VIP barlow combination for a while. I was thinking that my Pentax and Tele Vue eyepieces would be soon made redundant but it didn't quite happen for me 

I've had 3 of the Baader zooms - a Mk II and a couple of Mk III's. Didn't really take to those either. The 7.2-21.5 zoom, especially used with the 2.25x Baader barlow has been the first zoom that I've really taken to.

I guess the answer to the OP's questions is, well it depends who you ask !

I've split Sirius fairly regularly now for the past few years with my 12 inch dob and occasionally with my 130mm refractor as well. I've only managed Antares a couple of times and that was with the 130mm refractor.

I think you are further south than many of us @Armand Popa so Sirius should be that much easier perhaps ?

I'm at 52 degrees latitude here.

1 hour ago, Adam J said:

I asked a simple genuine question would one of these be a good bet in a F12 scope or should I consider something else, what makes them not stand up against similar at this price. I considered it a throw away comment as I did not think he gave sufficient detail for me to understand his opinion as a none expert in eye peices especially in relative performance terms. I think Vlaiv expanded quite well on what John said for me.  I am not the type to just take what someone tells me as a given I need to know exactly why they have that opinion so I can decide if I should follow it. One way or another I was just asking for more detail.

Adam

After I read your view that my comment was a "sort of throw away comment" I lost interest in your post, hence no direct answer to your question.

Dave / F15Rules has now addressed that - thanks Dave

If stocks were available I would also suggest looking at a Panaview, 2 focal lengths of which are just £1 more than the Superviews. Again stocks allowing, the Aero ED's, particularly the 35mm and 40mm are much better eyepieces than the Superviews, in my humble opinion, and only slightly more expensive than the FLO pricing of the Stellalyra branded ones.

By better I am referring to the sharpness of the star image in the outer part of the field of view. Even at F/12 you may see some distortion with the Superviews,  but again that is only in my humble opinion.

Yours and others "mileage may vary".

Hope that is a more comprehensive answer to your question

1 minute ago, cloudsweeper said:

Well there's not much down for the rest of us then!  (Apart from Armand, that is!)

Doug.

I probably don't spend enough time trying Doug.

As I've posted elsewhere a few times, I don't really specialise in any particular type of target - I'm just a "sky tourist" really

I can split 52 Orionis with my 130mm triplet refractor which is about the toughest that I regularly observe.

Maybe I ought to spend more time on them with my 12 inch dob ?

I do enjoy trying for very uneven brightness doubles such as Sirius and Antares.

6 minutes ago, Armand Popa said:

John, thank you. I like that kind of challenge  It is really difficult to split, but the satisfaction is great

So do I but I just can't seem to split many of them !

What an impressive list of doubles to have resolved !

Personally I find sub-arc second splits very hard to achieve. I might have managed a couple of them but that's all.

Well done for having the skill and patience to tackle such challenging targets.

Meanwhile, back with one eyepiece and using one eye, having my 1st view of Mars for quite a few days just now. The clear gap won't last long but the details showing at 225x and 257x with my Tak FC100 are quite nicely defined. All the dark stuff is in the southern hemisphere with this side of Mars. Two clear bands of darker surface with a paler strand in between them. South polar cap tiny but visible. Paler areas close to the northern polar limb - probably clouds ?

The more northerly of the dark bands is the Mare Cimmerium I think and the more southerly one the Mare Chronium perhaps with the paler Eridania area separating them.

The angular diameter of the Martian disk is 17.5 arc seconds currently, which is about as large as it will get at the next opposition, 2 years from now.

Personally I find the Nagler zoom an outstanding eyepiece for double stars. Currently I use the 2mm-4mm with my refractors and the ability to instantly rack up or down the power is very, very useful when pushing the scope / conditions / observer on tight double stars.

The 3-6mm is still in production. Expensive when new but can be bought for somewhat less used.

If it's a 5mm fixed then the XW or SLV would be my suggestion.

I have used wide angle eyepieces which were nice to observe with in an F/10 scope but, in my opinion, were not nice at all at F/6.5 and awful at F/5. By "not nice at all" and "awful" I mean that I might as well be using a narrower field of view eyepiece and have saved some £'s and weight.

I don't expect lower cost wide angles to present pinpoint stars in the outer half of the field of view when the scope focal ratio is F/7 (ish) or faster but I would like them to be at least roughly looking like stars rather than the elongated "seagulls". Some manage this, some don't

I'll be blunt (sorry FLO !) and say that for £70 a throw, the GSO Superwides are over-priced IMHO.

Just my views though and others will undoubtedly vary

I find using more magnification rather than less more effective from where I observe. 31 mm is now my longest focal length eyepiece. Until recently I had a nice 40mm 68 degree but almost always got more satisfying views with short focal lengths. I've owned a few 50mm eyepieces but never for very long

These GSO made super wide eyepieces are fine as long as the buyer is aware of their limitations. Their pricing needs to reflect this as well IMHO.

vlaiv has made some excellent points regarding them so I don't need to add any more

M33 visually resembles an indistinct patch of light sitting between 4 stars in a rough rhomboid formation. This is the nearest image of what it looks like though a scope that I could find at short notice:

This would be under a pretty dark sky. As you can see the object is large and low power is used.

I have seen M33 with 7x35 binoculars and my 11x70's show it on a decent night here. A little away from the faint galactic haze is a slightly more condensed small spot of light close to a foreground star. That small patch is NGC 604 which is a vast star forming region within the galaxy M33. NGC 604 needs about a 130mm or larger aperture to detect.

Unless you are observing from very dark skies, M33 is very indistinct even with a 10 inch scope.

I've seen Mars occasionally for a few minutes between the clouds over the past few nights but other than that, no observing possibilities.

Going through a "lean patch" here, observing-wise

I've owned the 50mm and 42mm GSO branded versions of these eyepieces and can confirm what vlaiv has said above regarding performance and specs. The Stellalyra ones do look extremely like the GSO Superviews.

I enjoyed them in an F/10 refractor and SCT.

I strongly suspect that the Revelation Superview's are the same eyepieces ?

1 hour ago, Johan03 said:

Is the TV Nagler 3-6mm zoom compatible with the Dioptrx lens? Found no info on TV website but maybe that is because they are not compatible. Website only states Dioptrx fit on all focal length Type 6 Naglers. Do the 3-6mm zoom belong to the type 6 serie?

The Nagler zoom is a 5 element design with a 50 degree apparent field of view across it's zoom range. It is not related to the 82 degree Naglers apart from that it was designed by Al Nagler.

Not sure about Dioptrix compatibility

Sounds like a great project Michael

As well as the resources you have already mentioned, I find the Stelle Doppie database useful:

https://www.stelledoppie.it/index2.php?section=1

Plus Stellarium's info on binary stars seems quite accurate.

Quite a lot of the sights that visual astronomy provides could be thought of as unimpressive on the face of it. A faint smudge of light, a subtle darkening or brighter spot on a small planetary disk, a barely visible point of light.

But when a little understanding of what is being observed is added to the mix then the visible evidence takes on a lot more fascination.

The smudge of light is a galaxy whose light has taken millions or tens of millions of years to reach us or maybe a newly discovered comet that is soon to whisk off into the depths of the solar system never to return in our lifetimes. 

The contrast variation on a planetary disk is a massive storm system that has raged for over 300 years or maybe a canyon 4000 km long and 200 km across.

The pinpoint of light is a rocky, icy ball orbiting a distant gas giant millions of KM away or maybe a massive star reaching the end of it's life in a supernova explosion that outshines every other star it it's home galaxy.

This stuff can be seen with amateur telescopes and our own eyes if we put our minds to it. It's what keeps me in this crazy hobby

The Universe with end with a Gnab Gib according to the Hitchhikers Guide

38 minutes ago, Don Pensack said:

...I wonder how many of these are the same zoom in a different housing:

Agena	Zoom	7-21
Agena	Zoom	8-24
Altair Astro (UK)	Lightwave Zoom Premium	8-24
Apertura	Zoom	9-27
Astromania	Zoom	7-21
Astromania	Zoom	8-24
Baader Planetarium	Mark IV Zoom w/click-stops	8-24
Celestron	Zoom	8-24
Discovery	Zoom	7-23
Discovery	Zoom	8-24
Leica	Aspherical Zoom	8.9-17.8
Lunt	"Solar Eyepieces"	7.2-21.5
Meade	Series 4000 Zoom	8-24
Meopta	Zoom	7.3-14.6
Omegon	APO Zoom	7-21
Omegon	Cronus Zoom	7.2-21.5
Omegon	Flatfield Zoom	7.5-22.5
Omegon	Magnum Zoom	8-24
OpticStar (Opticstar Brand)	Zoom	7.2-21.5
OpticStar (Opticstar Brand)	Zoom	7.5-22.5
Orion	E-Series Zoom	7-21
Orion	Lanthanum Zoom	8-24
Orion	Zooom!	7.2-21.5
OVL (First Light Optics)	Hyperflex Zoom	9-27
OVL (First Light Optics)	Hyperflex Zoom	7.2-21.5
Pentax	XF ZOOM	6.5-19.5
Pentax	XL Zoom	8-24
Russell Optics	Zoom	8-16
Saxon Australia	Zoom	7-21
Saxon Australia	Zoom	8-24
Sky Mentor (Khan Scope, Canada)	Zoom	7-21
Sky Mentor (Khan Scope, Canada)	Zoom	8-24
Skywatcher	Hyperflex Zoom	9-27
Skywatcher	Hyperflex Zoom	7.2-21.5
Skywatcher	Zoom	7-21
Skywatcher	Zoom	8-24
Telescope Service	Planetary HR	7.2-21.5
Telescope Service	Zoom	7-21
TeleVue	Nagler	3-6
Vixen	Zoom	8-24

Lots I expect, but not the Nagler zoom

The Nagler zoom is one that I do think rivals good quality fixed focal length alternatives.