F15Rules

My newly cobbled together eyepiece set after selling most of my hi end eyepieces to help fund my Tak FS128.

All Japanese glass ?..

From left to right:

Vixen LV4mm

Tak LE 7.5mm

Celestron 10mm plossl with reticule

Pentax XL 10.5mm

Meade 4000 swa 13.8mm

Meade 4000 15mm plossl

Tak LE 18mm

Meade 4000 26mm plossl

Vixen LV 40mm

Older designs all, but all very sharp across the field?.

Dave

On 2017-5-16 at 21:17, John said:

I think the DL has a slightly tighter spot diagram, whatever that means. Probably more to do with the different focal ratio rather than differnt figuring quality though.

The official blurb at the launch said this (Google translated from the original Japanese, so blame that !):

"In recent years of refraction telescope, but Photo visual system short focus apochromat has become the mainstream, it is the emergence of these and differing length personality focus two ball fluorite apochromatic telescope FC-100DL.
FC-100DL in the FC type which arranged the street flow light lens of the name behind, worthy of long focal refraction of f / 9.0, chromatic aberration, you get high spherical aberration less contrast image. Specifically, halo is approximately 40% reduction of the g-line against FC-100D of f / 7.3 (purple), and has realized the 97.5 percent of about 4% increase in the Strehl ratio that indicates the high magnification performance. (Data calculated)
This aberration data is almost the same number as the three pieces ball apochromat, coma is coupled with stable image plane of the zero, I think that you understand that it is a telescope that has a high-eye viewing performance."

 

 

John, that does sound as though the DL is claimed to be optically "better"....as a long time fan of good long focus achros, I grew up reading that the shallower curves on longer FL objectives were/are easier to polish and figure to a high standard? Also, even on an ED "apo", longer focal lengths reduce CA even further, maybe light scatter too?

I'd LOVE to see an F11 or F12 115-125mm ED Fluorite doublet tested ?..

Two other things I still like about long achromats...you get more depth of focus, ie more range of "sweet spot", within which you can get perfect focus. This is such a boon at high powers: on my D&G 5" F15 I had a moonlight dual speed focuser, but even with the original 2.7" AP focuser I could always get a snap to focus, even up to x300 on good nights. On my FS128 the snap to focus range is much less.

The second noticeable property is that Airy disks are larger with a long focus achro, really tight, but larger, you really get the "twin bullseye's in black" effect on doubles like epsilon Lyrae.

But long, big fracs are a real pain to handle sometimes, especially when viewing near the zenith, and as you get older.. Gavin, if you find the Tec140 more of a handful than the AP130, imagine the fun and games you'd have with a 2 metre long tube!??

Dave

On 2017-5-15 at 00:29, John said:

It's funny with scopes. Last year I bought 2 "dream" scopes, the Tak FC-100DL and the TMB / LZOS 130 F/9. They are both superb instruments and undoubtely the best scopes of their respective apertures that I've ever viewed though and arguably in the top few ever made at those apertures for amateur use.

You would have thought that the old, slightly scruffy gold tubed ED120 Skywatcher would have had it's marching orders ?. But no, I keep coming back to the Skywatcher of all things. I guess that it's the whole package that is "right" with that one which includes size, weight, ease of mounting, cool down, ruggedness as well as optical ability way above it's price band. Still trying to figure it out .....

 

 

Hi John,

The few reviews I've read of the first (gold) SW Ed scopes (both 100 and 120mm) seem to really rave about them. I wonder if that is because, as a crucial new product for Synta at the time they were so important and they really really tried to make them to an outstanding quality? 

Having said that, I know many with the newer versions love theirs just as much. I do think there is something quite classy about the older gold tubes though..I personally prefer them to the black diamond of the Pro Series or gloss black of the Equinox. 

Now, if they offered them in classic white with black trim, I might even become a convert! ????

Getting back to Gavsters original post, that Starfire must be a complete cracker if it is doing even slightly better than the TEC.. 

Not a bad "problem" to have, comparing two of the best fracs on the planet???.

Dave

Hi Dave,

Good to hear from you, I hope you are keeping better lately?

For those who don't know, Dave built the tripod I now have the FS128 on, i must have had it over 6 years now and it's solid as a rock.

Dave also got me into bigger fracs originally, with his great reviews of Helios 6" F8 achromats. If they are still on the archives here, they are a cracking good read!

I've at long last had a look at the sky with the scope. I'll put a few thoughts on the observing forum, but it's no kind of proper first light, I suspect that will have to wait until the autumn at the current rate of clear skies where I live..

Dave

As we've had wall to wall cloud since Friday evening, I decided to put the FS128 and EM2 mount on my fixed height hardwood tripod to see if it is more rigid than the original EM2 tripod.

I've used this tripod for about 6 or 7 years and it has coped really well with some heavy scopes, including a Celestron 150mm F8 achromat.

As I suspected, it is significantly more rigid than the EM2 tripod, being made from thicker timber and being braced by a very good Berlebach accessory tray. The damping time is now between 1 and 2 seconds, so I will use this configuration for first light (if it ever comes!).

I've also set up the RA drive now?.

A few pics of the scope on the above tripod..

Dave

Thanks, David, very interesting.

I also like targeting double stars and have got Sissy Haas' catalogue to start ploughing through, ideal for a 5"?.

Dave

2 hours ago, DRT said:

Congratulations, Dave, what a fantastic set-up

Having personally witnessed your legendary ability to resist buying and selling astro equipment I am sure you will comply with all the pleas above to make this one a keeper    

I hope you get lots of enjoyment with it - the views should be superb!

Thanks Derek..I think!? Anyone would think I bought and sold lots of stuff?????

I do sincerely intend for this scope to be my all rounder..I've said before that I think for a refractor lover, a good 5 incher offers the best of most world's as an all rounder: a real step up from 4",  but more manageable than most 6" and a lot cheaper than hi end 6 inchers too.

I loved my excellent D&G 5" F15, (now happily looked after by Steve (Saganite), but at 2m long, the tube and it's mounting requirements defeated me: the Tak is only about half that length though, so I hope I'll be able to handle it in the longer term.

Just want that first light!! - but Scotland is having all the best weather at the moment!?

Dave

2 hours ago, dweller25 said:

Hello Dave,

Only just found this thread....

Welcome to the FS128 club

MIne was made a year before yours and has given me 9 years of great views. I have replaced the original focuser with a Feathertouch which is a perfect match for the quality of the OTA.

Have fun with it - and never sell it.

Here is mine in action......

 

Hi David

Thanks?. I hope mine will be with me for as long as yours has been with you. I just can't wait to have a proper session with it.

I plan to keep the original focuser but will probably get a baader helical micro focuser to give that extra precision at very high powers.. I've used one before and they are very good. How high do you go with yours on very steady nights?

Dave

Chris and John are right, Vixen collaborated/collaborate with Synta on scopes and also have eyepieces made there, I think NPL and SSWs..

I think they made things worse for themselves by doing this, they effectively devalued their brand in my opinion.

I think part of the attraction of Vixens has always been their "Japanese-ness", and by allowing some of their products to be made in China, they cheapened the whole brand. And for what gain? You don't find many Vixen China ED80s about compared to the Synta ED80s..partly because the SWED80s are so good, but also the Vixen China models are so much more expensive, with not that much better optics. But the all-Japanese built scopes such as the ED103s I owned just "feel" so much better... better mechanics, components, machining etc, and definite worth a significant price premium, but surely not 2 or 2.5 times the Chinese equivalent?

Takahashi, by contrast, did not partner with the Chinese, and their products have much higher resale values. 

I do have some sympathy regarding the currency though. It must be very frustrating for businesses which crave stability for the currency, to keep having fluctuations from non-business causes. That said, it doesn't seem to affect other Japanese firms to the same extent?

I just hope Vixen can survive outside of Japan (where I believe they have c 60% market share) in the long term.

Dave

I have used a number of Vixen products and have nothing but praise for them. I had an ED103s apo refractor- excellent..2 Vixen Great Polaris  mounts - excellent..numerous old and newer Vixen eyepieces - excellent.

I do think Vixen new prices in the UK are much too high. However, if you are buying just once, you have to look at it over the life of the product.. I recently sold my trusty GP mount with MT1 motors and new DD3 handset (which now costs £199!) for £185 or so. It was around 17 years old but still in excellent condition and A1 working order.

Many of the used GPs that come up for sale will be a similar age.  I very much doubt that ANY Skywatcher EQ5 mounts will be around after 17 years. They are built to a (very good) price, but something has to give at the price they go for. I think that something is longevity and precision of engineering.

Please don't think I'm knocking SW mounts, they have been the door into using proper mounts for many amateurs (me included), but it does surprise me sometimes that people will spend a fortune on top notch optics but put it only on a mass produced cheap mount? That said, I have done that myself..in my case, I had limited funds overall and chose to spend most of those funds on the optics of the system, "making do" with a cheap, but perfectly usable mount that could be replaced just as cheaply if and when it needed to be.

Personally, I wouldn't blame anyone for buying a top class mount especially if they intend to keep it for a long time.

The only watch out is that at the new price quoted, the Vixen will suffer very high depreciation, much higher than Takahashi for example.

Hope that's of some help?.

Dave

25 minutes ago, Alan White said:

Those added pictures, wow what a nice pair of scopes.

The new house looks nice too.

Thanks Alan, we love the new house and hope to stay here for a long time?. Skies are dark, with just a couple of wretched sodium lamps in the lane, but I'm going to ask the council to put up a screen behind them..wish me luck on that!?.

Dave

Thanks John, the pictures don't really show the true difference in size of the two scopes but I thought they make a nice pair?.

I've added some more photos now onto the original thread, hope you like them..

Dave

Here are a couple of my new (to me) Takahashi FS128 just acquired 4 days ago. We had visitors all weekend til early afternoon so only just had a chance to set her up.

I haven't fitted the RA motor as yet, the EM2 mount has just an RA drive but also slow motions on each axis, ideal for my visual only needs.

The other scope for comparison is my 80mm F15 Moonrakered refractor with Kenko Japan 1980s lens on a CG4 mount: the Tak EM2 is much more robust- as it needs to be to handle the big Tak tube?..

Dave

On 2017-3-24 at 15:31, deejay said:

Here's my vintage £58 GBP ebay buy TOWA 80mm, stripped of its scratched worn paint job and the red vinyl covering I put on it as a temporary measure. I have taken it down to the metal on the tube and polished it, as I did with my Tasco 550 featured earlier in this thread. I may have it professionally Chromed on the main tube and finder tube and possibly brass finished on the Dew shield and finder dew shield. It looks great in the corner of my living room as it is  even my wife approves!!

That looks great, and good optics too boot! It'll look like a Skylight F15 by the time you're finished?..

Dave

Hi all,

I'd just like to thank everyone so much for their kind words and for joining me in celebrating what for me is definitely the scope of a lifetime. 

At the moment the scope is in boxes as we have visitors over for the Bank Holiday and I don't want to be rude by disappearing off into my mancave with a long metal tube...but as soon as decently possible I will be getting up close and personal with it!

A few early observations (sorry) on the scope itself.

The overall condition can only be described as "mint". It is virtually unmarked, even though it is 18 years old. Serial number 99008, so built in 1999, the 8th of it's type of that year to be built. The mount was built in 1998, and is, I believe, the model before the EM10 which morphed into the EM11. I think the main difference between them is that my earlier EM2 only has RA electric drive, with slow motion controls to both axes (I think the EM10/11 came with GOTO). That is absolutely fine by me as I am visual only, although I do like to track with the mount at high powers. The manual states clearly that on good nights magnifications of x100 per inch of aperture are readiliy possible. The  Tak finder is 7x50mm and beautifully built, with helical focuser and I believe it has an illuminated reticule with it...certainly, one can be retro fitted to it if not.

The scope also came with Tak LE 7.5mm and 18mm eyepieces, (I have used 18mm LE's before and was very impressed with them), a Tak 1.25" diagonal prism, and a very interesting Tak Vari-Extender, which apparently can give a range of barlow type increased magnifications from 1.6x to up to at least 3x, perhaps more.

The mount itself is of lovely build, with polar illuminated scope and flawless finish. It's definitely "beefier" than my recently sold Vixen GP mount, I would say closer to the GPDX in size. It seems overengineered for the official 7kg capacity, and I believe the true capacity to be nearer to 10kg. We will see. The scope tube weighs 7.5kg, remarkably light for such a large tube. For those of you that are familiar with the Skywatcher/Helios Evostar/Celestron CR 150mm achro F8, the Tak is of similar diameter tube, but shorter and much lighter. It's an impressive looking tube, with flawless finish. The large 2.7" focuser (R&P) is buttery smooth. This is the first Tak I have ever seen in the flesh, and, nice though they look in photos, I honestly think they look so much better in real life.

The optics on the lens are like new, clearly never touched or cleaned, in a beautifully engineered oversized cell which is fully collimatable , (I will NOT be touching that though!). The single cradle for mounting the tube on the eq mount is very heavy duty and feels rock solid.

The tripod is fully extendable, made of hardwood and looks ideally suited to supporting the mount and scope, again in as new condition.

I think I am going to have some fun with this setup!

I'll post more in the equipment review section when I've had a proper chance to set it up and have first light. And pictures of course...

Thanks again for all your kind posts everyone

Dave

1 hour ago, Chris Lock said:

You must be climbing the walls, Dave, fingers crossed for first light very soon....and please don't delay in telling us about it  

I won't Chris..the scope also came with Tak prism diagonal, Vari-Extender and 7.5mm and 18mm LE EP's:-)...

Dave

16 hours ago, John said:

Jupiter is ruling here right now

GRS is showing really well !

Hope you have some clear skies with you Dave

 

Hi John

Typically we had cloud and weekend visitors last night so no first light or even assembly of the scope yet

Hopefully soon though :-)

Dave

11 minutes ago, estwing said:

I disagree....455mm rules..

How about "Steam Funnels Rules"?? ????

9 minutes ago, Chris Lock said:

No I didn't dream it, Dave definitely has an FS128!  

Thanks so much for all your kind comments!?. They are so appreciated..

Just got home with the scope (the photo was taken on my phone at the sellers house) and am tired out but exhilarated.

I'll post more photos and info in the next few days.

Thanks again to all.

Dave

10 hours ago, Rainmaker said:

My "Final" setup, after years of testing various Taks, is pictured here:

 

TOA130NFB with Baader BBHS 2" Sitall Mirror Diagonal and Baader SkySurferV Finder and TSA102S with Baader Zeiss T2 Prism, Televue Binovue and a few eyepieces on AZ-EQ6 GT

Beautiful setup Rainmaker, with quality accessories to match:-).

I could certainly be happy with that as my "Final setup"??

Dave

My lovely Foxy the Vixen ED103s has made way for Lady Diamond, aka Skywatcher Black Diamond ED120 DS Pro..

Awaiting first light (maybe later tonight?:-)), and Lady D has a hard optical act to follow!

I've upgraded her with a lovely gold Moonlite dual crayford and Altair 60mm RACI finder.

Seen here on my trusty Vixen GP and heavy duty wooden tripod?

Dave

This looks very like a Towa made scope. Towa (series known as Circle T as their logo was a circle with a letter T inside it) were a Japanese mass producer/seller of various types of scope in the 60s/70s/80s mainly. Their refractor optics were good, sometimes excellent. I don't know about their reflectors, but they should be ok, however the fancy lens-inside-the focuser arrangement worries me a little. 

If you have all the parts though it should be fine to get you going, as Peter says..when you're ready to go to the next stage, ask for some advice on this forum and you will be sure to get some great advice.

Good luck and let us know how you get on:-)

Dave

On 16/11/2016 at 14:43, Saganite said:

Thanks Chris, I knew you would like it !

It certainly was worth the effort, as I can now get the best out of it. 

Apart from the groundwork , I need to connect it permanently to the power supply transformer.

On 16/11/2016 at 11:51, Saganite said:

Many of you will have seen this telescope , a 5" F15 D&G Optical, on this forum , very early in the thread. I have owned it for just over one year, and it is a long held wish, come true.

My EQ6 and tripod has been fine, but I knew from the start that I would have to mount it on a pier, to reduce the damping time from 4 seconds plus.

A tap on the OTA would cause the " tail to wag the dog " so to speak. I tried loading the tripod with weight,and anti vibration pads, all to no avail.At high magnification the movement of the image, even using the fine focus was just a complete irritation.

The pier is constructed with 6" dia steel tube with .25" wall, 15mm thick steel baseplate, and 12mm thick webs. On the top is  the "owls nest" thatI purchased some months ago on AB&S, which again is very thick steel construction. Bolted to a concrete block with 16mm resin anchored bolts, it has exceeded all my hopes and expectations. It is so heavy and solid that, as the picture shows, it handled the OTA just fine, before I bolted it down. My "grab N go" Tal RS gives some idea of scale.

I have had a single 4 hour session since reaching this stage, and the damping time is under 2 seconds ! A nudge on the tube produces no discernable vibration in the pier, and the " icing on the cake" is that I can now focus without any movement of the image. It has been properly polar aligned, so tracking is accurate for the first time ever, which is another bonus.The eyepiece is one metre from the ground when it is pointed to the zenith, so I can sit comfortably on my chair instead of crawling on the floor. The downside of course is that it is pretty high when observing at 30 deg above the horizon, but fortunately I do very little of that. The groundwork around the site is yet to be finished, and I will probably devize a two level system to  help with this.

I did not get an observatory through planning, but my winter clothing set up for observing is very good and I am quite happy with this minimal arrangement, besides I prefer to know that the OTA is locked in the garage when not in use, and set up time is now  just minutes. 

Note the hedge in first picture has been removed by my neighbour, in the week or so between shots, which rather blew my attempts at disguise right out of the water.

A thinly veiled acceptance of this " thing" in the garden, will have to do, but if anyone knows the secret of the Klingon Cloaking Device, please drop me a line, else I may be too busy trying to hide it, to observe with it.

Hope you like it.............I LOVE IT

Hi Steve,

She looks MAGNIFICENT!??

When I owned this scope I always knew that a heavy duty mount like this would be needed to get the best out of what is a superb 5" F15 objective..this D&G beauty is one of the 3 optically best scopes I have owned, along with the Vixen ED103s and a Ylena (Lomo) 6" Mak. And, on this mounting I think it could well be top of the pile. On a good night she just eats magnification and the contrast is superb.

Many congratulations on having the vision of how you could pair this wonderful scope up with a worthy mount!??

Dave