Andrew_B

4 hours ago, JeremyS said:

Interesting, Gary. My Tak “vixen” dovetails are also 40mm, but my non brand Vixen style dovetails are 43mm. 
 

This is why my Tak dovetail is too narrow for my ADM clamp that I bought 2 or 3 years ago,

BUT I happen to have a second ADM clamp purchased last summer, but not yet installed. That grips the Tak dovetail perfectly. So they must have made adjustments to the ADM clamp.

I had the exact same problem as you Jeremy, in that the Tak dovetail was too narrow for the ADM clamp fitted to my AZ GTi that I bought during the summer.

Sounds like it's an issue with that one particular model of ADM clamp.

The Tak dovetail is great quality and surprisingly lightweight but is a little bit narrower than some other dovetails on the market which can be an issue getting it properly secured if your saddle doesn't have much inward travel on its locking bolt. That wouldn't be a problem with the saddle that comes with the Scopetech Zero (I have one myself) but anyone needing a wider dovetail might want to look at ADM's 7" Vixen-type dovetail or the smaller and cheaper 10cm long model from Lacerta, both of which are drilled and tapped with a pair of holes 35mm apart to match those in a Tak clamshell although the latter is only available from a couple of European sellers.

2 hours ago, johninderby said:

There are many fine scopes that you never seem to hear much about in the UK. Has anybody actually used a Planewave? One of the unaffordable scopes I would like to own. 😢

https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Categories/Shop/"Telescopes %26 Binoculars"/Corrected_Dall_Kirkham

Planewave, Officina Stellare and various others seem to make a lot of scopes aimed at the professional end of the market such as tracking objects in orbit or for defence applications where spending $50k+ each on a few scopes is pocket change. I suspect that's where most of their business comes from because there surely can't be that many wealthy amateurs who can afford to spend that kind of money.

3 hours ago, ollypenrice said:

It would be interesting to come back to this thread in 25 years because, if we look back 25 years, I don't think the premium scopes would have such a hard time distinguishing themselves. That's because the budget scopes have improved so spectacularly.  Digital imaging has raised the bar in terms of expectation, imagers wanting faster F ratios, wider corrected fields, better and more extended colour correction and load-bearing focusers. But, for a visual observer, how much better than a Skywatcher ED100 is it possible for any 4 inch refractor to be? There is, quite simply, not much room for improvement. A little, yes.

Similarly, by how much can a Takahashi six inch be better than an Esprit 6 inch? £5K versus £13K.  

25 years from now, will the Tak-equivalent products be reduced to the product-for-product's-sake end of the market now occupied by Questar?  Questar don't make telescopes, they make 'collectibles.'

Olly

The expensive stuff has generally come down in price. A Tak is about half the cost it was in 1990 in real terms but standards across the board seem to have improved over thus time to give more consistently good optics and mechanicals. Quality control is still expensive though even if automated manufacturing reduces much of the variation so there's still likely to be a place for higher end products that are uniformly that bit better.

Visual observers don't drive the market very much these days so it probably doesn't matter whether the differences between mid and high-end scopes are minimal to the human eye. An extra £8K for the Tak is a lot of money but when you add the cost of cameras, filters, mounts, computers, and possibly an observatory, the difference in cost of the total setup might not be that large and it becomes far easier to spend extra on a better version of a component. I've got a few Baader filters and can't imaging paying 10x as much for the likes of Chroma but if I had a really fancy imaging rig, the cost of a filter upgrade wouldn't seem quite so bad when I'd already shelled out a fortune on the rest of the kit and wanted to get the best out of my investment.

While the focus is on optical performance, what's often forgotten is that higher end gear will often have better mechanicals, nicer fit and finish, and be built with a higher standard of quality control (although that doesn't mean the odd lemon never gets produced). The latter, in particular costs a lot more to implement than many people realise and is a major part of where the higher manufacturing cost of premium optics comes from. While high-end telescopes for the amateur market might seem expensive, they're dirt cheap compared to specialist optics for the aerospace and defence sectors and much of their high price tag comes from the stringent testing they have to go through to ensure they work perfectly - I bet if you got L3Harris to build you a telescope it would make the likes of Tak and A-P seem like the bargains of the century!

I've got a small refractor which is very much an indulgence with its superb optics and addition of a Feather Touch focuser. The latter seemed like a crazily expensive upgrade but I'e found it to be worth the money to have such an incredibly precise and solid piece of engineering performing the vital task of finding and keeping objects in perfect focus. I ended up with a scope that works exactly as I want so while it's undoubtedly expensive for what it is and I could have got something far bigger and more capable for the money, I should get years of enjoyment from it for less than the price of a cup of coffee per week. The huge Dob that I could have bought instead would actually have been a poor investment since I have nowhere to keep it, don't want that type of telescope and the practicalities of transporting, setting up, and observing with such an instrument mean that even if I did want one it would never get used.

Value for money is always an interesting argument. Small to mid-sized refractors are probably the best example due to the huge range of models at every level of price and performance and it can be hard to see the value in buying a top end scope instead of a midrange Chinese apo that would be almost as good for half the money or less. Equally though, does that Chinese apo really offer good value when compared to a cheap achromat? Many people would say no but if you like high magnification views and you're bothered by false colour then you won't be satisfied with the achro even if you do get a lot more scope for the money.

23 minutes ago, paulastro said:

Yes Malcolm, Takahashi owners do like to talk about the experiences they have had with their telescopes.

I remember a post about Takahashi telescopes a little while ago which was about the merits of licking the lense of their Takahashi!  I kid you not.  I remember who posted it, but I'm not saying 😇.

I think being a bit barmy helps if you're an astronomer, but Takahashi owners do seem to take barmyness to a new level 🤪.

 

 

I've noticed the same thing with other brands like TEC, A-P, TeleVue, LZOS and probably a few others but the relative scarcity of their scopes on the used market (especially in the UK), the fact that many of them are not available to buy off the shelf at the best of times (or available at all in the case of A-P), and their much higher cost of entry relative to Tak means there are far fewer people talking about them.

People love to eulogise about an expensive purchase they really enjoy, although I've sometimes wondered whether they're trying to convince themselves that spending all that money was a good idea! Then again I've seen a similar tendency in others to heap praise on very cheap telescopes, sometimes accompanied by remarks that anyone buying something more expensive must have more money than sense.

3 hours ago, vlaiv said:

If it is down to lanthanum - we would need to wait some time to detect it

only 0.1% of lanthanum is that radioactive isotope and it has half life of about 10 ages of universe - so we would need quite some time for one to decay, even if there is substantial amount of the stuff in the glass.

It would be more likely to be the chemically toxic effects of lanthanum that would cause problems. Uranium is similar - the stuff would poison you chemically well before the radiation level was enough to harm you.

Prop 65 is one of those idiotic laws that labels pretty much everything because just about every product will contain something that causes or is suspected to cause cancer. There was a similar flap a few years ago in the UK when a bunch of food products like ready meals were removed from sale in the UK with great fanfare because they contained a cancer-causing additive. When you read the details it turned out that the chemical in question had never been shown to cause cancer in humans in any circumstances or when ingested by animals and it was only when lab rats were injected with absurd quantities of the stuff that it was observed to have an effect. A person would die from overeating or from ingesting a lethal amount of salt long before they could get a similar concentration of the chemical in their body but nevertheless it was considered 'dangerous'.

Unfortunately, when safety labelling is overused people just tune it out and it makes them much less likely in future to pay attention to genuinely important warnings.

Part of the reason is probably that at least with modest sized scopes, it's not actually that expensive to own the very best so why not have it?

A high-end model could be several times the cost of a midrange alternative that would get pretty close in terms of performance but it's still likely to a bargain compared to what a similar optic would have cost 30 years ago (if it was even available), and much less than many people would pay for a car that might get replaced every few years or a new kitchen.

On Svbony's website the 10mm is a bit cheaper still (€47.35 / £40.11) while the 18mm isn't quite so competitive (€77.49/ £65.64).

19 minutes ago, John said:

Yes, I was surprised that it occurred myself. I wonder if it is because my T2 prism barrel is smooth - no undercut

The 1.25" nosepiece I use with Baader 32mm prism is also smooth and hasn't caused problems so I'd be surprised if it was that. The only time I've been conscious of having to make an effort to undo the clamp is when I've attached a diagonal or eyepiece that's had an undercut or taper and in those cases it was't stuck, it just needed a lot more undoing.

10 hours ago, John said:

I use the Tak twist lock / visual back to hold the Baader Zeiss T2 prism but on the other side of the prism I have a Baader click lock T2-1.25 inch adapter. One of these:

https://www.firstlightoptics.com/adapters/baader-click-lock-125-inch-eyepiece-adapter-with-t-2-thread.html

The Tak silver ring clamp is where I have had issues. I guess having it sometimes hard to loosen is better than having uncertainly about it being tight enough though !

 

That's an odd problem to have. I normally use the Tak 1.25" twist lock visual back on my FS-60CB/Q, together with the basic 32mm Baader T2 prism in a similar arrangement to yours but I don't recall ever having issues with the diagonal nosepiece getting stuck in the clamp.

28 minutes ago, UKDiver said:

A combination of heat and, I wince to say it, direct use of mole grips, did the trick. Some scuff to the silvered wheel though. No grip with something between. No idea how it got so tight.

It's weird how adapters can get so tightly stuck when you know for sure you didn't fix them that strongly but at least you got it sorted in the end and any damage was only cosmetic.

If you ever want an adapter to stay in place no matter what you can use the same trick. Heat the adapter so it expands then screw it onto whatever you're fixing it to and when it cools it will shrink tight onto the thread, a bit like how they attach metal tyres to train wheels.

If you can, try and heat the adaptor by itself and keep the prism as cool as possible 

You could try heating it up which should expand the metal and allow you to separate them. Even sitting it on to of a radiator for a bit should get it hot enough. 

14 minutes ago, 12green said:

How will these compare to BST Starguiders in F10 SCT ?

 

I'd expect them to be a bit better and when my 10mm eyepieces arrive I'll do a side by side with my 8mm Starguider.

The nice thing about having an f/10 SCT is that the long focal ratio and relatively flat field should enable most eyepieces to perform at their best.

5 hours ago, UKDiver said:

A lot of the Svbony kit on their Amazon site is 20% off for Prime members/Black Friday deals. Including the scopes.

I just ordered the 10mm and 18mm UFF for £120 the pair. Should be here tomorrow, far quicker than Aliexpress can do and just slightly cheaper.

So it might be worth joining Prime for a year a £79 just to save £100 on a scope. If you think the scope is worth the price (I've no idea).

Be interesting to know how you get on with them and that's a good price for both.

I've pulled the trigger on a pair of 10mm Svbony UFFs for my binoviewer but they're coming from China so it'll be a while before I get to try them out.

23 minutes ago, Louis D said:

I'm thinking early adopters like myself helped reimburse Marcus for his UFF R&D expenses.  After that initial period of higher prices, it appears that the line will be offered at lower prices by others.

A similar thing happens in the pharmaceutical industry.  It can cost billions to bring a single new treatment to market when accounting for all of the dead end ones that get shelved.  As a result, these R&D companies have to make that money back while their patents are still valid.  After they expire, the generic manufacturers jump in, manufacture them, and sell them at slim margins since they don't have very much R&D expenses to recover.

Have APM reduced their prices since those early days? I notice that while there are bargains to be had in the shorter focal length eyepieces if you shop around for less well known brands, the APM 24mm and 30mm models are no more expensive than the competition and in some cases are quite a bit cheaper.

1 hour ago, bomberbaz said:

I stand corrected and apologise for my wrong assumptions. I would have thought there is some illicit copying going on but obviously not as widespread as I may have presumed. 

No apology necessary. You made a good point about the issue of cloned products or poor quality kit that masquerades as better quality gear. It's not an issue in this case but people should be aware that it can happen and they shouldn't support the practice even if it would mean getting a bargain.

5 hours ago, Louis D said:

According to this CN post, Mark Ackermann of the US designed the 30mm (and I believe the rest of the APM UFF line) at Markus's request.

Thanks for the info. I read that APM had the exclusive rights for two years then KunMing United Optics were free to manufacture the same design for other brands.

Brands currently offering some or all of the range (10mm, 15mm, 18mm, 24mm, 30mm) are Altair, APM, Celestron, Meade, Orion, Svbony, Sky Rover, and Tecnosky.

1 hour ago, bomberbaz said:

Somebody made a good point on the CN thread about buying from the reduced cost suppliers who are simply copying the designs of others then under cutting them.

The designers, in this case APM have spent a lot of cash producing this line and need to have a higher price to recoup that cost and then hopefully use some of that profit to design new glass.

Svbony for all their quality are apparently copying others designs and although their quality and after service is good, should we really be supporting this plagiarism at the expense of innovators?

Maybe this should be a separate thread!

If Svbony are copying APM then so are Celestron, Orion, Tecnosky, Altair Astro, and probably a few others. They're not knockoffs or copies because they're coming out of the same factory and are optically identical although external cosmetic appearance may differ. It would be interesting to know whether Marcus bought in a set of off the shelf eyepiece designs to sell as the APM UFF range or whether they were his own design (I'm sure I read that he reverse engineered someone else's design but I may be mistaken) and he didn't sign an exclusivity agreement in order to secure a lower price from the factory.

You see this with astro gear all the time with the same product being sold under a variety of names but there's nothing underhand going on or anybody getting ripped off. FLO fo example have their in-house Astro Essentials, StellaMira, and StellaLyra brands which feature products that are the same as those offered by name brands but cost a lot less (Astro Essentials Plössls are the same as Celestron Omni Plössls but at half the price). 

The only thing buyers need to be careful of is when buying from anywhere overseas they may have less protection than they would under UK consumer law, and even if a vendor is happy to repair, replace, or refund faulty products you can still incur significant costs if you send items back. You may also find that help and support is far less forthcoming than it would be from a UK seller which should be borne in mind when thinking about the potential to save money.

38 minutes ago, bomberbaz said:

try this

https://www.aliexpress.com/item/1005002314488490.html?spm=2114.12057483.detail.3.c5ab407634Vnhm

Svbony also sell direct https://www.svbony.com/sv190-ultra-flat-field-18mm-eyepiece/ although there are some Svbony branded items I've seen elsewhere that they don't currently offer on their own website.

45 minutes ago, Zermelo said:

This one? £44.99

This is what CN has to say:

https://www.cloudynights.com/topic/781526-are-these-eyepieces-clonescopies/

That's the one I saw.

Normal caveats apply if you're thinking of buying from an overseas supplier. Make sure to check what guarantee is in place and also consider whether it's practical to return an item if there was a problem given the cost of sending it back.

On the whole I've found buying from the Far East to be fairly problem-free and the customer service has generally been first rate.

10 minutes ago, bosun21 said:

Which SVbony eyepiece?

Sorry, should have put a bit more info in there. The 10mm is the one I've seen at that price and the 15mm and 18mm I've seen going for around £65-70.

They sell them on places like eBay and Aliexpress - if you're buying from the latter make sure to check delivery times because some of the real bargains are obviously sent over on the slow boat so you could be waiting a while!

6 hours ago, bosun21 said:

Thanks for your feedback on your experience using the eyepiece. I’ll pass on them as for the price they are asking for them in some of the sizes i could buy three BST’s

The generic versions are quite a bit cheaper at around 45 quid for the 10mm and around 70 quid for the 15mm and 18mm, although I've seen a lot of different prices for the same things so it's worth doing a bit of bargain hunting.

They're also sold under brand names such as Orion, Svbony, and Sky Rover, and are usually labelled as Ultra-Flat or Ultra-Flat Field with a FOV of 60 to 70 degrees depending on model.