F15Rules

Fascinating thread, Stu, thanks for all the interesting details.

The AZ100 is a super looking altaz mount, really solid looking and with amazing load capacity.

A couple of quick questions if I may..

- how heavy is the basic manual mount?

- forgive my ignorance, there seem to be various optional add-on accessories.. do the encoders mentioned give the mount sidereal tracking capability? I've always favoured a driven equatorial mount, as I like to be able to hold an object in the centre of the FOV for 10-15 minutes..would this be possible on this altaz mount using any of the listed accessories, perhaps as a later retro-fit option? If so, that would greatly add to the attraction of this mount for me.

Thanks for any light you (or any other users of this mount) can shed for me!) 😊👍.

Dave

1 hour ago, RodAstro said:

Hi all

Yep as you say Rusted f15 is a big operation I have a crane stored away for working on mine.

Yes it is folded and has the bonus of fixed eyepieces. Orientation is not a big problem, you just let the object drift then you know where you are.

As you say Rusted mounts are the biggest problem for large refractors another plus for the folded design is you end up with a correct size mount, not very portable though. The RA axis of my mount is the basis for the 36" Zeiss cassegrain so I have no problem piggy baking other scopes. 

Out of interest I would like to hear views of others with long focal length refractors on eyepieces they use. 

 

Cheers Rod 

Hi Rod,

I used a lot of (much smaller) F15-F16 refractors in the past, and found them all pretty good with most eyepieces, due to the sheer focal length of the scopes: the joke used to be that a decent long frac would deliver up great images through the bottom of a Coke bottle!

With my D&G 5" F15 I found this to be largely true, but because of the relatively narrow field such a focal length delivers, I preferred eyepieces with a wider field of view, such as Pentax XW and XL ranges (70deg and 65deg respectively), Vixen LVW (65), and Explore Scientific 24/28 and 34mms..the 34mm in particular, gave superb lower power views of clusters such as the Double Cluster in Perseus.. I say lower power, because the D&G, with a focal length of 1920mm still magnified the 34mm to about 57x.

I also loved using traditional high quality orthos on Lunar, Planets and double stars..the long frac's depth of focus meant that dual speed focusers were really not essential, and the simple design and great transmission of orthos such as the Baader Genuine Ortho (BGO) range could yield some breathtaking images under steady skies. Sadly, my aging eyes now prefer a bit more eye relief, and I find binoviewers much more comfortable for many types of observations.

In more modern designs I find the Baader Morpheus range offer a great combination of wide field (76 deg), contrast and sharpness and value for money. I think they would be outstanding in a good long focus refractor.

Nowadays, it seems that most people seem to want shorter and shorter scopes and wider and wider fields, requirements that only the newer, more exotic designs of eyepiece can satisfy, such as Ethos and others of 100 degree fields or more. My own Tak FS128 at F8 is seen nowadays as a fairly slow focal ratio scope, but when I was a young man any refractor of under F10 was seen as pretty fast! 

I will always admire long achromats with a well figured lens as delivering some of the purest, most contrasty and sharpest images you can get.

Dave

Rusted,

Ok, you've convinced me..

Giant refractors are actually malevolent mechanical monsters bent on the destruction of the puny mortals that drool over them!😱

I'm sticking with my tame little FS128 5" F8!! 😄

Dave

8 hours ago, RodAstro said:

 

Deleted (double post)

8 hours ago, RodAstro said:

Yep F15 rules

Here is a picture of what I own and use day and night over the past 15 years. Mine is one of three that is in private hands, only two are working.

The 6" lens is in the class of apochromatics visually and is of steinheil design, flint first.

One of the great things of F15 refractors is they have wonderful flat fields and are very tolerant of eye position at the eyepiece, unlike modern short apos, even F8s.

This is the public observatory at Brisbane as it shows the size of the scope. The scope was designed to fit a six foot observatory, mine is in a seven foot observatory and hard to get a photo that shows its size.

Cheers Rod

Fascinating scope, Rod. I take it that's a folded design?

If that was in Brisbane and you're in Derbyshire, it sounds like there is a story there that deserves a thread of it's own! 

Thanks for posting 🙂

Dave

6 hours ago, Peter Drew said:

I made loads of telescopes for loads of people but never loads of money!.  A "labour of love".     🙂

Fancy building me a nice 6" F15 as a labour of love, Peter?? Pretty please???😊😋

Dave

Lovely looking setup!

Congratulations 👍

Dave

Hi Rusted,

Wow, wow wow!!

I am truly in awe of your creations, they look amazing and I can only imagine the views and satisfaction of having built them yourself.

I especially love the look of the first photo, on the wheeled dolly? 

I knew Peter was a wizard scope maker, both from his reputation and having been to Todmorden just once, he kindly helped me to collimate a Russian Mak I had at the time: he kindly showed me some of the amazing stuff he keeps in his domes, this was some 12 years or so ago, maybe more.

I take my hat off to you both, and thanks so much for sharing your insight and images, you've made my day✌️🤘👍😊😎

Dave

Hi Rusted,

Thanks for your fascinating insight into the challenges that building such a Behemoth presents: you clearly have extensive experience of these challenges!

All joking aside, and as a lifelong refractor fan, (including long focus achromats, on which I cut my teeth, so to speak, hence my F15RULES handle😁), I totally see that for anything much over 6"/150mm aperture, reflectors of whatever type are much more practical for amateurs to own and use regularly.

Given the practical issues, especially of mounting, associated with such large tubes, you can perhaps see why the owner of the 12" in this article sounded "muted" in his actual observing experience of using the scope!

I know from my own experience of owning a quite wonderful D&G USA 5" F15 achromat (see photo below of "Andromeda", of which I was the first owner, but which is now in the care of Steve (Saganite), and my thanks to him for the Pier photograph),  that secure, solid mounting is everything if you want to truly exploit the scope's optics to the maximum..and this scope was "only" c2 metres long..the second photograph shows Andromeda I believe on an EQ6..the Pier was much more suitable according to Steve, and I believe it!

Is there any chance of us seeing some pictures of your own collection? I'm sure I'm not the only one who would love to see and admire them?😊👍

Thanks again for your insight.

Dave

On 04/11/2020 at 21:20, Barry-W-Fenner said:

Have you had much chance to use your Morpheus range Jiggy? If so how are you finding them? Any particular favourite. I have the 6.5,9 and 14mm still debating which to get next 🤔

Hi Baz,

I have used 9, 12.5, 14, and 17.5mm. I felt the 12.5mm and 17.5mm to be the best and I currently have a pair of 17.5mm for binoviewing.

Other than for OCD reasons of getting a full set, I would t have both the 12.5mm and the 14mm, they are to close together..I like the gap between 12.5 and 17.5, personally.

I haven't tried the 4.5mm or 6.5mm as yet. Of course, YMMV, as our US friends would say..🤔😉😊.

Oh, and regarding Fireworks night, I personally wouldn't go out if there were bonfires burning, as I wouldn't want ash debris floating onto my objective or mirror! We are fortunate in our village that very few people have young kids, and most do have a pet dog or cat, so very limited appetite for wretched Fireworks..

HTH,

Dave

1 hour ago, Mr Spock said:

Amazing scope. A proper scope at that. But you have to admit a Newt is far more practical.

..and there was I thinking that you Newt guys would like a Refractor that looked like a ships' funnel!!😊

Dave

2 minutes ago, JeremyS said:

Is that a pair of skis under the pier?
I suppose it would help getting  the instrument from storage in the dining room out to the field.

No Jeremy, the wooden posts were meant to be for a handle, but he couldn't lift them high enough..🤔

Dave

Thanks, John. Exactly my thoughts too! It just looks amazing, and I'd love to have looked through it. I wonder where it is now?

Dave

I've recently acquired some old (1969) copies of Sky & Telescope magazine, and this scope was on the front cover of the March 1969 issue.

As it's such an old issue, I hope I'm not infringing any copyright rules by copying the accompanying article here, for our members interest, with full acknowledgement to Sky and Telescope as the original source over 50 years ago. If I have that wrong, my apologies and Mods please delete this post.

The scope  just made my jaw drop, being a home built (apart from the objective) 12" F16 achromat. 

You have to admire the owner's vision and determination to build such a huge scope and then use it!.

I hope you enjoy the article🙂.

Dave

They are are Russian Zomz or Tento or similar 8x30s.

Based on an old Zeiss Jena Jenoptem design made on machinery taken from East Germany after the war.

Built like a tank, good optics, sometimes with a yellowish rings to the view, but very sharp in the field centre and with good contrast.

Lots about on the 2nd hand market so not valuable moneywise, but as an heirloom worth keeping and using whether by day or by night.

Enjoy 😉👍

Dave

I doubt the WO nosepiece is to blame..mine gives pretty much equal performance to my Baader Hyperion Zoom Barlow unit.

Dave

Great thread, Rob and well done on getting some great views at last!👍😊.

A good prism diagonal will definitely give you more in focus  leeway.

I use the Baader T2 prism with my FS128 and Revelation bvs. I can just get sharp focus with NO ocs or Barlow with my pair of Morpheus 17.5mms, so about 55x in my setup. 

I actually prefer to add in a Baader 2.25x zoom Barlow or WO 1.6x nosepiece for Mars and other planets as you need more magnification to extract maximum detail..I've also found Mars to be just too bright at low power.

The Tak 1.25" prism is also very good, but IMO the Baader T2 prism with either the 1.25" T2 nosepiece or a low profile 2" barrel one is better able to handle the heft of a bv loaded with two heavy-ish/largish Morpheus eyepieces - I wouldn't trust that lot hanging off the lightweight plastic collet of the Tak prism!

Using Binoviewers can be very frustrating until you get it right, and takes thought, preparation and experimentation..but boy, when it comes good, it delivers an outstanding and satisfying observing experience!😎😁

Dave

Orion for me, every time.

There are just so many interesting objects to see, with naked eye, big scopes, small scopes, for everyone, however experienced or new to the hobby, whether visual only like me, or imaging enthusiasts.

Dave

Great links John, thanks for sharing!

Orion has been my favourite constellation since I was 15 and used to just gaze for ages at M42 through my little Prinz 550 60mm F15 Refractor (Circle T optics and rather good actually).

Even now, 50 years later, I get inwardly excited at the prospect of cold, clear nights wondering if I will see both e and f stars of the Trap! 😊👍

Dave

Lovely, Fozzie. You can't beat a white Refractor IMHO!

Looks like you should get a decent moonless clear night later this week, fingers crossed for you!

Dave

58 minutes ago, johninderby said:

Getting towards winter when FLO will change the labels. 🙂

Got this one last winter. 🙀

I dearly wish we could get some snow this year... followed by some crisp, dry dark skies for viewing Orion..luvly jubbly!👍😁

Dave

12 minutes ago, JeremyS said:

Nope, I did read it all Old boy 🤣

...and yet you still persisted, what??😋😁

Lovely read, thanks Bob..

You are tempting me to get another copy of TLAO to replace my long gone one!

Got up the other night to answer a call of nature, and looked out of the hall window to see Orion rising higher to the south east, Procyon in Canis Minor now visible, with Sirius south of that yet to clear our horizon.

I am really looking forward to getting out with my favourite constellation before much longer!

Dave

Thanks Jeremy!

1. As I'm slowly shrinking as I get older, F10 probably better represents my physical reality than F15...

2. I prefer to clean off other people's lick marks than to add my own..

And finally...

"Oh, and have you thought about a handle?"

2 hours ago, F15Rules said:

PS: I'm not planning to get a handle for this scope, before anyone asks!!😋

Do please a chap's entire post before replying, old chap   😋  😁

Dave