Andrew_B

1 hour ago, John said:

I'm expecting the lens elements of my Tak to melt, explode or disintegrate any day now, according to comments made in another thread on another forum

Clearly I've taken a big risk unpacking the scope when it arrived and then using it regularly since then

The hilarious thing is that people genuinely believe that the companies which have been making and using these lenses for decades would risk using materials that apparently break at the slightest touch, dissolve in normal atmospheric moisture, or shatter if you so much as look at them funny.

2 hours ago, johnturley said:

Sometimes the coatings can be quite delicate, I managed to damage the coating on an early (pre Starfire) Astro Physics Refractor than I used to own, probably through not being as careful as I should have been when it came to cleaning, although I think that the coating was a lot more delicate than that on a Vixen Refractor that I used to own at the same time. 

Nowadays I think the coatings on most lenses are a lot tougher than they used to be. 

John 

Anti-reflection coatings made of magnesium fluoride are very soft so perhaps that's what you experienced. I think these days it's usual to add a hard coating of something else like silica to provide extra protection and scratch resistance which might have been what your Vixen had.

24 minutes ago, Louis D said:

Which two are you referring to?  It could be simple matter that the FPL-53 version is old stock bought at a lower price in the past while the FPL-55 version is new stock bought at higher, pandemic pricing.

It can also be related to different grades of glass. Apparently there is a wide variation in cost of a blank of any given glass type so it's possible that TS-Optics have specified a better quality of FPL-55 for their scopes to ensure better performance and fewer duds in the finished lenses.

I think your explanation is the most likely one though.

4 hours ago, markse68 said:

Aren’t Lomo still going? Telescope express used to list lomo newt mirror (can’t find it now) and APM list some RC mirror sets- rather at the professional end of the price spectrum though 😳

https://www.apm-telescopes.de/en/lomo-optics

Maybe they just can’t produce consumer grade products at a price point that’d sell?

For all that high end consumer scopes can seem expensive, I gather the prices are a fraction of what scientific and military optics sell for so companies that cater to the upper end of the consumer market usually do it as a sideline to other things. LZOS are a good example; they make incredible optics for the amateur astronomer but it's only a very small part of their business and the real work is in things like military and space optics and they couldn't run their massive facilities on the income from selling lenses to APM. I can only imagine how expensive one of their space-qualified 650mm aperture lenses would be!

Definitely give it a go because it's a superb lens that you've already got!

Turn off autofocus because it won't work except maybe on a bright subject like the Moon, and turn off IS as well. You don't need to worry about dew other than to try and prevent it forming while you're shooting; these L series pro telephotos are designed to be used in the pouring rain so a bit of dew won't harm it in the slightest.

A good teleconverter shouldn't significantly degrade the image quality but I'd hold off buying one until you work out whether you really need it.

The vulnerability of fluorite lenses is rather overstated. I found this quote about the material:

"CaF2 is used as an optical component because of its chemical stability under adverse conditions. Exposure to 100% relative humidity at room temperature does not fog polished surfaces even after 1 month. In normal working conditions, polished surfaces will not degrade. For temperatures exceeding 600 °C, calcium fluoride surfaces will degrade in the presence of moisture. In dry environments, calcium fluoride can be used up to 1000 °C, and it does not begin to soften at 800 °C. Calcium fluoride is inert to organic chemicals and many acids, including HF. It will slowly dissolve in nitric acid."

I know some of you will be tempted to use your scope inside a furnace or wash it in nitric acid but don't do it!

Another article on the stuff talked about uncoated fluorite lenses lasting years with normal exposure to environmental conditions such as moisture and temperature changes and it's worth remembering that modern lenses are coated anyway with much harder and moisture-resistant materials (might be silica or other oxides of zirconium, titanium, etc) that protect the fluorite underneath.

1 hour ago, JeremyS said:

My Tak FS102 is 20 years old and still in good condition. One or two minor chipsonthe tube but you have to look close. Optics as bright as new. Just as well fluorite, glass and metal don’t deteriorate if well looked after 🤣

You won't be laughing when that clamshell fails and your beautiful scope crashes to the ground, delicate fluorite element first!

These things need to be protected and if you can still see the tube, you haven't got enough tube rings!

1 hour ago, HollyHound said:

You should be ok with that FT. The WO comes with a 1.6x Barlow, which also provides additional “in focus”. Try with and without 👍

By the time the FT turns up I might well be in the market for a binoviewer and I'm sure I'll get one at some point. The 3D view of looking through the Baby Tak with a long FL eyepiece is already impressive with one eye so using both should be spectacular.

The prism and clamp turned up today and work perfectly with the usual Baader build quality. Not had a chance to look at the night sky yet with the current weather but tried out the microfocuser on some distant ground targets and found it did the job well. The only combination that's a bit of a struggle to use is with Baader's own Hyperion Zoom eyepiece which was a bit of a surprise - the base of the main eyepiece body butts up against the focusing ring and makes turning it a bit awkward. Adding the 2.25x matching Barlow to the eyepiece solves the problem completely by giving it more standoff distance.

1 hour ago, ScouseSpaceCadet said:

I've managed the Cassini Division in all my scopes, from the first 130p newtonian to the current Skymax 102 and 102mm ED refractor. Although 102mm is the lowest aperture I've owned. I'd guess in your case it's a combination of poor seeing, just barely enough aperture and old eyes! 😉

I imagine local light pollution would also be a factor. If a street lamp is in the direction you're looking through the scopes that won't help. Likewise viewing over buildings. However I'm sure you already know that.

Also remember since 2017 Saturn's full tilt of 27° seen from Earth is decreasing until 2025 when they gradually return to full tilt in 2032. We all just need to stay alive until then!

 

 

From what I've read, light pollution is relatively unimportant for planetary viewing provided a nearby lamp isn't close enough to your FoV to cause glare.

Viewing over buildings or things like dark asphalt surfaces can mean looking through very turbulent heat plumes that can severely degrade local seeing even if the sky itself is relatively steady and transparent.

I think Tiny Clanger is on the money with her points about ease of use and intuitiveness when it comes to the choice of a refractor or a dob. I found it was a lot easier to get used to navigating the sky with only left-right reversal of the image rather than having it upside down as well and it's a lot easier to line the tube of a refractor up to a target than most other types of scopes. Obviously a finder largely takes away the need for that, but finders can also need to be aligned in the first place.

Another factor is that a moderately sized refractor can make an excellent spotting scope for watching birds and wildlife even with just a regular diagonal without having to spend the extra for an amici prism. This greatly increases the opportunities for using the scope, especially when the weather makes stargazing impossible.

2 hours ago, HollyHound said:

I do use a WO binoviewer hence why I prefer the shorter light path of a prism.

it is indeed threaded onto the scope, for extra rigidity 👍

Do you need to use a Barlow lens or glasspath corrector to reach focus with that combo.

I like the idea of using one of those to make viewing more comfortable and natural but some of the arrangements I've seen have an awful lot of gear hanging off the focuser. That's partly why I spent the money on the FT for the FC-76 to give me the option of binoviewing without worrying that I'll overstress the Tak focuser.

8 hours ago, RobertI said:

I’ve not tried shorter FL  eyepieces to be honest - I happened to have the barlow already and it worked perfectly and gives just the right magnification in the 100ED. I imagine that the eye relief is better than using short FL eyepieces too. It’s possible I’m missing out I guess! 

If you're already getting up to 175x magnification then you're probably not missing much by not having shorter FL eyepieces except on nights of very good seeing.

8 hours ago, BobInYorkshire said:

Thanks, I bought a Skywatcher Adventurer 2i a couple of weeks ago and managed to use it for half an hour last night in between cloud cover.

The results weren’t brilliant but at least I got a bit of practice in and learnt a few things.

I would like a telescope too so that I can do visual observations and later do some astro photography with it as well.

Good luck with your attempts.

 

You can do an awful lot with a tracking mount and a few camera lenses from wide angle to short telephoto and even get into things like narrowband imaging which can deliver spectacular results.

The learning curve with astrophotography can be very steep and it's important to find a workflow that you get along with using software that you find a pleasure to use rather than a confusing irritation. I think it's also important to get some good images when you're starting out because it gives you a real boost and it's exciting to show them to friends and family, and that's a lot more likely if you keep things as simple as possible to begin with.

It's nice to have a scope because it gives you something to do while you're sitting out with your camera during an imaging session! To start with though I'd stick to using the camera and lenses to get the hang of astrophotography and maybe just use the scope to take some shots of the Moon.

Things like the accuracy of your polar alignment and tracking errors in the drive itself become much more of an issue with a telescope due to its long focal length and I found that I couldn't quite get round stars with my scope until I'd added an autoguider to my setup which is obviously more money and complexity.

Starting with a simple approach is way more fun that attempting too much too soon. My first go at imaging through my scope was done out in the field (big mistake, do it at home first), using a narrowband filter for the first time (what was I thinking?), in the middle of a gale on the North York Moors in January (I couldn't feel my fingers). That was not an enjoyable experience or particularly successful 🤣

1 hour ago, Deadlake said:

Just seen a review of this scope in bbc sky at night. Gets the thumbs up, however the interesting part is the TOA like design.

This ask’s the question what’s the difference with the FLO version.

Made in the same factory but do they have the same lens cell? 

 

 

Would be interesting to know what the lens spacing is like. The TOA uses large air gaps between its elements in what looks like a modern take on a Cooke Triplet but that kind of arrangement is more prone to losing collimation so you need a very substantial cell to keep everything in the right place and collimation screws to adjust things if there was a problem.

3 hours ago, RobertI said:

I have the William Optics binoviewers - they work really well in all my scopes. To get the magnification required for planetary I use the Baader 2.25x barlow* which actually results in roughly 5x when used with the binoviewers, so gives around 100x in the 66mm and 175x in the 102ED. Another advantage of binoviewers is that the image seems so much bigger - it's an illusion created by the brain, but a huge difference to the observing experience. Also reduces effects of floaters in the eye. Can't recommend them enough.  

*You will need to unscrew the lens of the barlow and screw it directly into the nosepiece of the binoviewers to get best results. I have it permanently attached.

That looks like a pretty decent setup for the money. Do you use the 20mm eyepieces or are other focal lengths better for planetary observing? 

4 hours ago, HollyHound said:

That’s just a Baader T2 extension ring (15mm).

Nice, this will be perfect for your scope 👍

It looks very securely fixed, presumably threaded onto the scope rather than using the eyepiece clamp.

Do you use a binoviewer at all? It's something I might get in due course and I'd imagine I'd need a more secure attachment than a compression fitting.

3 hours ago, RobertI said:

I second that! Binoviewing is just amazing for solar sytem observing. I usually use it in my 102ED but a couple of nights ago I tried it in the C8 and my little 66mm APO. The 66mm was a revelation, with a lot of detail evident in Jupiter, more than I thought a mere 66mm could do. And it's comfortable which really ecourages more crticial observing for longer periods.  👍

Which model of binoviewer do you have that's suitable for use with smaller scopes?

3 hours ago, HollyHound said:

In answer to your original question, I have both the small and larger Baader T2 prisms on all my Taks and they work superbly 👍

There isn’t too much difference in light path length between them I don’t think, but yes the smaller are much cheaper… unfortunately I haven’t seen them in stock anywhere for a good while… I think I might have bought the last one FLO had😬

That's a very neat setup. What's the connector between the prism and the rearmost Takahashi adapter?

I managed to find one of the little prisms in stock at RVO so I've ordered that plus the ClickLock T-2 eyepiece clamp with the built in helical focuser. I've already got a T-2 nosepiece so I should be all set when it arrives.

I found this manual for the telescope which talks about replacing the 0.965" eyepiece holder with a 1.25" version.

From what you've described it sounds like your adapter is adding to the length of the existing 0.965" eyepiece holder which results in there being too little in-focus distance to be able to bring objects at infinity into focus. You'd need to remove the existing eyepiece holder as you tried already and then replace it with the 1.25" version.

Is the outside diameter of the drawtube 38mm? If so I saw an item mentioned on this forum thread in post #9 that might do the job.

1 hour ago, JeremyS said:

Sound like you need to consider a Tak FOA 60 Q at some stage 🤣👍🏻

Get thee behind me satan! 🤣

I don't need anymore temptation and that FOA 60 Q looks like a very nice bit of kit, both optically and mechanically. You should get one and let us know what it's like!

17 minutes ago, jadcx said:

They are phenomenal little scopes  Although not quite so little by the time you've constructed the 76Q variety, but still, I'm very happy with it.

I can feel my bank balance slumping as my Feathertouch envy grows.  

The 76Q is like a proper old school long refractor but even in that mode it's not at all heavy.

I don't want to think how much I've spent 🤣. I'd budgeted a certain amount for a scope plus some accessories like a good diagonal and a widefield eyepiece but I've definitely gone over that amount. Scopes like these are the kind of things you can own for a lifetime and they're small enough that no matter where I end up living I won't have a problem storing or using them.

I've also used my Z61 as a spotting scope quite a few times and I'm eager to do some birdwatching with the FS-60Q once I've got a suitable diagonal.

4 minutes ago, JeremyS said:

Great plan, ending up with two scopes. Well 4 actually: FS 60, FS 60 Q, FC 76 and FC 76 Q. The FC is actually quite a capable planetary scope as you have found 👍🏻

When you put it like that it's an absolute bargain!

I was surprised at how good the view was through the FS-60Q as well and it seems that the longer focal ratios do a better job of cutting through bad seeing. I've tried it in FC-76Q mode as well but not really had the seeing to take advantage of magnifications over about 150x so I'm looking forward to taking it out under dark skies as well as viewing the Moon when it's higher in the sky.

The standard FC is incredibly good and so lightweight. I'm not an experienced observer and conditions haven't been great but I was still able to see colour and detail in the GRS. There's a lot to be said for a small scope - last night I was viewing the Moon from out of my kitchen window because it was too windy to take the scope outside. I wouldn't have been able to do that with a big dob!

25 minutes ago, JeremyS said:

I use the Tak prism diagonal for my smaller Taks: FS 60 Q and FC 76 DCU. Great performer. It’s also light and compact.

Note that eyepieces with the dreaded undercuts are slightly tricky as harder to grip and to extract. But I still struggle on with my TV Naglers. The Baader twist lock would be better (which I use with my larger Taks). Non undercuts (and Baader eyepieces with safety smurfs) are fine

I've ended up with the same two telescopes so I'm really looking forward to exploring their capabilities!

My plan was originally to follow @DirkSteele's example and put together an FC-76DCU(Q) from parts including a Feather Touch focuser so I ordered everything from FLO and it duly arrived apart from the focuser which is on quite a long lead time for orders. I then had 90% of a telescope sitting in boxes and was itching to use it so in the end I gave in and bought an ex-demo FS-60CB from FLO so that I could use its focuser and try out the various combinations of both scopes in normal and Q-modes. The Feather Touch is still on order so when it does arrive I'll have two scopes to play with.

Seeing hasn't been great here and the wind has been non-stop but I still managed to see the GRS and a shadow transit on Jupiter for the first time ever on Thursday night with the FC-76DCU. Even without being able to really push their capabilities I can tell that these scopes are punching well above their weight.

I encountered that eyepiece issue but fortunately I was anticipating it and none of my eyepieces currently have particularly big undercuts so it's not been a big problem. I think I'd be happy with either prism diagonal but I am leaning towards the Baader one for its flexibility and better compatibility with eyepieces, even if they're designed by lunatics who love undercuts! 🤣

20 minutes ago, jadcx said:

No there's definitely a bit left, but I can see the appeal of the micro focuser anyway as the FS-60 stock focuser is quite course for such a narrow focus plane.  I'm considering upgrading it somehow, maybe a 10:1 unit, maybe splashing on a Featherlite, not sure yet.

Thanks again, that's good to know. I got used to having a microfocuser with my ZenithStar61 that's mainly going to be used for imaging from now on. The Tak focuser is fine at lower magnifications, if not better than the WO focuser but when I push the magnification I could do with being able to adjust the focus point with more precision.

The Baader helical focuser in the eyepiece clamp is a fraction of the cost of any of the other options from Tak, More Blue, or Starlight Instruments so I figured it's got to be worth a go, especially if other much more experienced observers rate it highly.

6 hours ago, jadcx said:

I have the Tak prism with the same scope setup and it's very nice.  Small, short, and with excellent optics.  I went with this because I was focussing on portability, so the compactness was the deciding factor.

That's good to know and the Tak prism is definitely an option. I was leaning towards the Baader setup because I could have the microfocuser which I do miss when using higher magnifications.

Do you have much in-focus left when using the Tak prism or is the focuser pretty much racked all the way in when you're focused at infinity?