Highburymark

20 hours ago, Nakedgun said:

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14 pages on this one eyepiece? 

Brother!

 

 

 

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Probably a symptom of almost no new eyepieces for the past 4/5 years, combined with the unique popularity of the 3-8. 
What other launches have we seen? 
Tak TPL. Two new Pentax XWs. APM zoom. Maybe a couple of others I can’t think of.
Think this is the new normal. It’s a completely saturated market. SVB did well to exploit a rare remaining niche, where the only alternative is 4x the price. APM to a lesser extent with its zoom. 
 

Very nice indeed Dave - thanks for posting

9 hours ago, Don Pensack said:

It is when curvatures match that you see a flat field.  When curvatures are opposite, the edge is far out of focus when the center is focused.

FC is always more of a problem with larger field stops, too, so FC will be less visible at the 3.5mm end than at the 8.1mm end.

Yes indeed Don - but this has always made me wonder why we don’t see more people having field curvature issues with the many brands of flat field eyepieces (APM, Altair, Lunt, SVBony etc)? As there’s field curvature inherent in many telescopes. I haven’t used any of that range myself, and I don’t doubt they are excellent, but why buy flat field eyepieces unless your scope has a perfectly flat field?

I notice there’s a Sky Rover version online for around £275 new. Obviously it’s the same basic scope and an excellent price, but they don’t specify FPL-53, which the other brands do. Just say ‘super ED glass’ or something similar - might be worth checking.

I’m not picking up much field curvature at all - maybe it complements the opposite field curvature in my scopes? The 3-8 works well in all three of my refractors in this respect. In the F/6 60ED for example, just a tiny shift of the focus is needed at 3.5mm to make edge stars sharp. 
On the issue of parfocality, it’s very close to parfocal through the range. I don’t need to refocus between 8mm and 5mm, but below that, a small tweak required.

On 17/04/2024 at 12:56, AlcorAlly said:

@Highburymark How much does it weigh please, without the diagonal/eyepiece? 

It’s advertised as 1.52KG for the OTA out of the box - that must include the built-in mounting ring and dovetail. Sorry I don’t have any scales at the moment.

14 minutes ago, Mr Spock said:

I haven't started my review yet. I still have to give it a full workout on the 4" Tak. On the 12" I was able to use it at the 5mm, 4mm and 3mm settings on the moon a couple of nights ago. Field curvature wasn't as evident as longer focal lengths and not intrusive. The eyepiece was sharp at all settings against the 4mm Nirvana, 7mm, 6mm and 4mm Circle-T orthos, 6mm SLV, 3.5mm and 5mm LVWs, with some variation - it wasn't a match for the 8mm LVW and the orthos looked 'cleaner'. It couldn't match the 4mm and 3.3mm TOEs in any area; the TOEs were sharper, clearer and had better contrast; they were able to pick up the tiniest of craters - I won't be selling them!

I did note the magnification looked the same as the 3.3mm TOE at the 3mm setting - objective rather than scientific. I also had to fold down the eyecup to feel comfortable. My tiny 4mm ortho was easier to look though!

Yep - the lower setting of the 3-8 is closer to 3.5mm I reckon.
 

The various branded versions of this F/6 60ED refractor are all excellent. I paid £300 for mine a couple of years ago, but you’d be looking at a good secondhand deal now for £250. Clean, sharp optics with FPL-53 glass, a silky smooth and strong focuser, and sliding dewshield all add up to a very compact and capable package - and a proper telescope for visual or imaging.

Definitely go for the 60mm DS, even though it’s painfully expensive. The resolution and contrast increase are worth it. Personally, I’ve never thought proms suffered with a double stack system - they always look similar to single stack. And I wouldn’t read too much into the sweet spot point either - every etalon is different, and it’s impossible to know how two filters will combine until you try them out. Just my 2p worth on all the issues raised.

I’ve only had a couple of night sessions with the zoom so far, both with average seeing (on Moon and double stars), so still too early to form detailed impressions. Ergonomically no problems at all - mine is pretty easy to operate, not too stiff at all. The zoom action doesn’t feel quite as smooth and robust as the Nagler 3-6, but that’s a minor quibble. The optics are - as others have suggested - right up there with far more expensive eyepieces. I feel it’s at the two extremes of the range where other (I used Delite 3mm, XW 5mm and Baader zoom at 8mm for comparisons) eyepieces are marginally crisper. But I need to do more testing before making any definitive impression, particularly on planets. It’s bright and has good contrast. The biggest issue for me is lack of eye relief at 3-4mm. I can’t comfortably see the field stop at high magnifications without eyelash/lens contact. This might seem irrelevant when I have a Pentax XO 5.1 in my arsenal, which has even less ER (a ‘sporty’ 3mm, compared with around 6-7mm for the SV Bony), but with that eyepiece, I know I have to hang back, and therefore use it for short, critical detail views only. I couldn’t use the SV 3-8 at 3mm for long observations. But otherwise it’s clearly a really excellent little eyepiece. I don’t think it will beat existing class leaders, but for 95% of astronomers who don’t have problems with eye relief, it’s a single solution for planets, the Moon and double stars. Mine even came with a free T-shirt. 

I bought the SV zoom for £80. The Nagler is over £400! 

Fantastic! I love TeleVue scopes too - so any chance of a pic or two?

The SVBony zoom is very close to the Nagler, except really short eye relief at 3mm and 4mm (at least to my eyes), so I can’t see the field stop without touching the lens with my eye lashes. And it is sharpest in the middle of the range 4-7mm or so. So just a touch less sharp at 8mm (where my Baader zoom is slightly sharper, I was surprised by that), and at 3mm. 
It’s an incredibly good deal for the price. The main issue for me as a good all round planetary zoom is its lack of high-mag eye relief.

I’ll second an X-class solar flare. I was lucky enough to see one in detail, at around 120x, which clearly showed plasma moving in real time. I’d been solar observing regularly for eight years before I finally had the privilege though. 

On the subject of observing lists, I can strongly recommend the Springer book, Stargazing under Suburban Skies, which suggests 100 deep sky objects (and separate Moon and planet guides) for anyone suffering from varying degrees of light pollution. Written by members of the Loughton Astro Society, it’s a wonderful resource - one of Springer’s best astronomy books.

Sad to hear this news. I’m particularly fond of Prof Ian’s book Observing and Imaging the Heavens. He had an accessible writing style which makes him seem like a fried providing advice, and I particularly appreciated his interest in hydrogen alpha solar astronomy. For an overall introduction to serious astronomy, I don’t think there’s a better book.  

Just had a quick squint through the little 60ED with the 22mm T4, eye relief set to maximum. I hate observing with specs, mostly because I can never get comfortable or see the field stop - and here I could capture no more than about 80% of the AFOV. Am I doing something wrong? Even with the eyeguard down and my glasses laying flat against the eyepiece, it’s impossible to see 82 degrees. In the F6 Tecnosky, there’s also considerable field curvature, requiring quite a readjustment of the focuser to sharpen up details at the edge. This may all be irrelevant to you Alan - all I can say is I love the Nagler in my slower scopes, without glasses!

15 minutes ago, Alan White said:

Thanks Mark, do you use glasses with this one?
 

No I don’t Alan, but I can test it out with glasses later and report back

I love the Nagler too. It’s a big chunk of glass though, a consideration with light mounts. Too expensive new. But a gorgeous eyepiece.

The biggest difference I saw between diagonals was when I first traded up from the basic Celestron that came with the C6 to a WO dielectric. Noticeably brighter and sharper - in my experience at least. The difference between more expensive diagonals - be they mirror or prism - is pretty small tbh. They’re a bit like binoviewers - very close in quality - trying to distinguish them optically can be a challenge. But they’re all excellent, as long as they’re well collimated.

2 hours ago, LondonNeil said:

I've read good comments on the baader diagonal before,  but wouldn't a  mirror be better than a prism diagonal? 

Prisms are not advised for fast scopes below F/7 or thereabouts, but they’re great for slow scopes. 

Price in the States - around $1500 I believe. 

Here’s my bizarre solution, which works surprisingly well. I can’t remember how I sourced the parts to adapt it to a normal finder shoe, but I’m sure they are still available.

I don’t think there is anything out there that’s better value. The Tecnosky version is very nice but £100 more at Astrograph. The Skywatcher 100ED might have a small optical advantage at F/9, but I’d want to replace the focuser for binoviewing, hiking the price well above £1k. So the only decision is whether to go for the Starfield or Altair version, which is also £899. 
 

It’s visible at the end of totality - the top prominence - that prom has ‘lifted off’ from the solar chromosphere 

There is actually a lift-off prom on the Sun at the moment but can’t pick it up from the eclipse coverage

I can unreservedly recommend the Simpsons’ episode: ‘Bart of Darkness’, for lots of telescope-derived entertainment. ‘Bart Discovers a Comet’ too, though it’s not quite up to the peak of the former.