80mm ED and 120mm ED or single 100mm APO?

[Moonshane]

Sounds like a date!

[Stu]

2 hours ago, swamp thing said:

 

Sadly I cannot afford one Stu  
TBH if I had that sort of money I'd buy a Nikon 300mm f2.8 prime lens instead. Now that is an APO I'd buy tomorrow.
 

Given your skills with a camera, that would be a worthy investment! ??

Apologies Shane, back on topic....

[Stu]

31 minutes ago, Mark at Beaufort said:

I have enjoyed reading this thread and to be honest I always wanted a high quality APO - Takahashi or TeleVue. At the moment I have a 102mm Astro Tech ED doublet with a Starlight Feathertouch focuser and I love it. I quite fancy comparing my Astro Tech with Stu's Takahashi or Shane's 120ED at SGLX1 but my worry is my scope will be blown out of water and I will get frustrated and end up buying a better frac.

Mark, at least you won't be nervously hoping your expensive Tak doesn't get mauled by these better value scopes ???

[Moonshane]

If the seeing is poor, it might be a result for all of us!

[paulastro]

16 hours ago, mikeDnight said:

I've had three Taks to date, the first a FS128, which was big for a 5" frac and it needed at least a GM8 to mount it well. I then bought a FS152, which was even more massive and required a G11. They were both superb instruments but the bigger they became, the less I used them. Eventually I sold the 152 after my back gave way as I was lifting it onto the G11, which was mounted on a pier in my garden, and stood about 7 feet off the ground. At the time I took planetary observing really seriously and preferred looking directly through the refractor.

I decided I wanted to get a scope that would be more of a pleasure than a chore to use, so foolishly I believed the advert in S&T that stated "It Is What You Want It To Be"! and bought a NP101. It was a beautiful rich field refractor but it wasn't pure like the Tak's, and its planetary performance was not in the same league. I sold it a year later!

Enter the ED120! I bought a 120ED Pro which was an excellent all round performer. I later part exchanged it for an Equinox 120ED, as paulastro assured me that the writing on the lens cell travelled all the way through the tube just like Blackpool Rock. I think he lied! However I used the ED120 for six years or more before Tak reintroduced fluorite into their scopes. Eventually I just had to have one.

On the first night I looked through the FC100D I knew I'd made the right decision. In side by side comparison with the120 ED the Tak was noticeably better at revealing planetary detail on Jupiter, so much so in fact that I actually exclaimed WOW! as I saw the intricacy of the belts in the Tak. Despite the greater theoretical resolution of the 120 ED, it didn't reveal the same level of detail. It wasn't that the 120 was a poor scope, it was superb, and had on many occasions whopped the socks of much larger scopes on the moon and planets; but the little Tak just had defining ability and a vibrance that, although subtle, was not evident in the ED.

Over the last year the FC100 has almost never failed to impress me with its planetary performance. It takes power well, so well in fact that I've been able to use X474 on Venus and the moon, and have razor sharp, colour free views. 

On DSO's, the fluorite lens seems to perform well beyond its aperture class, as I've been able to detect the subtle nebulosity around the Pleiades like I've never seen in any scope irrespective of aperture. The flame nebula and IC434 extending down from Alnitak could be detected without the use of a nebula filter. Binary stars are great to observe in the FC and somewhat difficult targets like the E and F stars in the trapezium become observable with careful study on a steady night.

The FC100D is a great scope that punches well above its weight, but it's not immune to bad seeing, and it is still subject to the laws of physics. With good eyepieces and good diagonal though it will revitalise your observing as it is so lightweight and easy to mount and makes for a great grab and go set up. For many it would be all the telescope they'd ever need.

Mike

Well said Mike.   However, I do disagree with you in one major area.  The writing on the end of the cell DOES go all the way through the tube!!!!!!!!!!!!!!! 

[John]

One thing I need to remember when reading these threads is that my Vixen ED102SS, in it's day, was a premium 4" refractor. It's list price was well over £1K for the optical tube.

It's easy to denegrate the equipment you already have, probably due to familliarity, and think the grass is bound to be greener elsewhere but thats not always the case

 

 

[Moonshane]

Agree totally John.  This is one reason I plan on being careful and hopefully having a compare with Stu or perhaps even Mike if he's willing at some point.I at lucky enough to have some options of what to sell but will be taking my time on this one. I reckon a doublet would suit me best as my triplet It's quite heavy even at 80mm. What's eating at me to some extent It's that I have not used my 16" since last year's sgl (preferring the lighter more convenient 12") and have been using the 120mm quite a bit. I'll be using the 6" more more as well with Jupiter added Mars back in town.

 

[nightfisher]

9 minutes ago, Moonshane said:

Agree totally John.  This is one reason I plan on being careful and hopefully having a compare with Stu or perhaps even Mike if he's willing at some point.I at lucky enough to have some options of what to sell but will be taking my time on this one. I reckon a doublet would suit me best as my triplet It's quite heavy even at 80mm. What's eating at me to some extent It's that I have not used my 16" since last year's sgl (preferring the lighter more convenient 12") and have been using the 120mm quite a bit. I'll be using the 6" more more as well with Jupiter added Mars back in town.

 

I have to wonder is it time to sell the 16", it would really help fund the Tak

[Moonshane]

It would but I want to be more certain before I jump.

[cotterless45]

Jump into my pond ! The wonderful world of achros. I'll be bringing the C6r and the 102 to SGL. I have never thought of getting anything exotic as I'm visual with a bit of sketching.I'm quite taken with this talk of exotica !

Study the reviews of Neil English well.

 You're very welcome to pop around to the pre-unloved and rescued fracs.

under those clear skies !

Nick.

[John]

39 minutes ago, cotterless45 said:

.....Study the reviews of Neil English well.

 

 

Neil seems to have moved over to an 8" dob now

I'm sure he still has a very soft spot for achromat refractors though.

[bomberbaz]

1 hour ago, Moonshane said:

Agree totally John.  This is one reason I plan on being careful and hopefully having a compare with Stu or perhaps even Mike if he's willing at some point.I at lucky enough to have some options of what to sell but will be taking my time on this one. I reckon a doublet would suit me best as my triplet It's quite heavy even at 80mm. What's eating at me to some extent It's that I have not used my 16" since last year's sgl (preferring the lighter more convenient 12") and have been using the 120mm quite a bit. I'll be using the 6" more more as well with Jupiter added Mars back in town.

 

I read this thread about masking up my Dob shane and I did notice your comments just above a halfway down.

 

How times change mate 

[ollypenrice]

There is a fundmental flaw running through this thread. What's all this guff about either/or ???????

I know you can sell a car or a kidney but has anyone here actually sold a wife or a telescope?

Olly

[Moonshane]

True comments above. I think one 'mistake' I made was getting the 12" as since I did I have hardly used the 16"! Maybe I should use it again for a bit. Then I might sell the 12"!

[John]

I made a mistake with a 12" as well (oohh matron !). 

The mistake was to take you up on your offer to make me a dob mount. It's my most used scope by quite a way now, whatever the dynamic qualities of my refractors are 

[nightfisher]

9 minutes ago, Moonshane said:

True comments above. I think one 'mistake' I made was getting the 12" as since I did I have hardly used the 16"! Maybe I should use it again for a bit. Then I might sell the 12"!

looking at it in a logical way, maybe the 12 is the weak link and if it were re-homed the 16 might get more use again

[Piero]

Well, gentlemen, I would like to make a mistake too by buying a 12"!

So, we could write down a deal that as soon as I can find a stable place to observe within the next 3 years, I can grab one of your beauties .. ehm normal telescopes and do a bit of observation!    

 

The real problem with the Tak 100, is that you will end up looking more at the telescope than through it.. Seriously, who can say it isn't simply gorgeous! http://www.trutek-uk.com/takahashi/fc100dc.html 

[mikeDnight]

8 hours ago, Moonshane said:

cheers guys. Great posts from Mike and Martin.

which begs the question......when did it not and why?    I presume seeing was the culprit?

Is the D bit important or is it just a larger format focuser? Personally I'd think I will only use 1.25" eyepieces with this scope but maybe it's worth having the option?

Looking forward to (I hope) a look through Stu's over the SGL weekend in comparison with my 120ED.

Yes, it was the seeing that ruined the view, mainly due to a front coming in. It's actually pretty good at seeing through the seeing on most nights, even when looking through holes in the clouds.

I hope you get some good seeing when you observe with Stu's scope. I think it would be better if he let you borrow it for a month or two, then you'd have a chance to really get a feel for it.  just joking Stu!

The scope I bought was the DC version as this was the one they had in stock at True Tech. I'm a bit impulsive! The focuser was a bit firm when it arrived, I think all Tak focusers are set that way in the factory, so I adjusted it and it glides like butter now. I have added a Tak micro focuser, just for high power double star observing, but really it doesn't need it for general use.

Mike

[John]

Would it be correct to say that the Tak FC 100 can resolve to the Dawes Limit for 100mm of (I think) 1.16 arc seconds or can the Tak do a little better than that even ?

 

[mikeDnight]

8 hours ago, Moonshane said:

cheers guys. Great posts from Mike and Martin.

which begs the question......when did it not and why?    I presume seeing was the culprit?

Is the D bit important or is it just a larger format focuser? Personally I'd think I will only use 1.25" eyepieces with this scope but maybe it's worth having the option?

Looking forward to (I hope) a look through Stu's over the SGL weekend in comparison with my 120ED.

Yes, it was the seeing that ruined the view, mainly due to a front coming in. It's actually pretty good at seeing through the seeing on most nights, even when looking through holes in the clouds.

I hope you get some good seeing when you observe with Stu's scope. I think it would be better if he let you borrow it for a month or two, then you'd have a chance to really get a feel for it.  just joking Stu!

The scope I bought was the DC version as this was the one they had in stock at True Tech. I'm a bit impulsive! The focuser was a bit firm when it arrived, I think all Tak focusers are set that way in the factory, so I adjusted it and it glides like butter now. I have added a Tak micro focuser, just for high power double star observing, but really it doesn't need it for general use.

Mike

[mikeDnight]

39 minutes ago, Piero said:

Well, gentlemen, I would like to make a mistake too by buying a 12"!

So, we could write down a deal that as soon as I can find a stable place to observe within the next 3 years, I can grab one of your beauties .. ehm normal telescopes and do a bit of observation!    

 

The real problem with the Tak 100, is that you will end up looking more at the telescope than through it.. Seriously, who can say it isn't simply gorgeous! http://www.trutek-uk.com/takahashi/fc100dc.html 

When living in a country where it rains for a third of the year, having a pretty scope to look at can can help keep you sane!   

Mike

[mikeDnight]

3 hours ago, John said:

One thing I need to remember when reading these threads is that my Vixen ED102SS, in it's day, was a premium 4" refractor. It's list price was well over £1K for the optical tube.

It's easy to denegrate the equipment you already have, probably due to familliarity, and think the grass is bound to be greener elsewhere but thats not always the case

 

 

I still consider it a premium scope John. A few years ago I witnessed to my horror, my NP101 get thoroughly thrashed while observing alongside a Vixen 102 EDSS. Both scopes were looking at Saturn and the £3000+ NP101 literally got its backside kicked in no uncertain terms by a scope costing a third its price. It's days were numbered! It's sobering to consider such moments.

When we're discussing the pro's and cons of high end scopes, and I'm including the SW ED's in this, the differences are subtle and unless the seeing conditions comply, the differences may not at first be apparent. For me, I'm happy to pay a little more for a scope that has an edge visually, others will reason the difference isn't worth the extra cost. At the end of the day anyone getting an duff apo today would have to be pretty unfortunate.

Mike

 

[mikeDnight]

4 hours ago, cotterless45 said:

Jump into my pond ! The wonderful world of achros. I'll be bringing the C6r and the 102 to SGL. I have never thought of getting anything exotic as I'm visual with a bit of sketching.I'm quite taken with this talk of exotica !

4 hours ago, cotterless45 said:

 

 Study the reviews of Neil English well.

Not everything that's in print should be taken as gospel!

I have Neil English book Choosing and Using a Refracting Telescope and its a thoroughly enjoyable, and a largely informative read. However, there is a totally misleading statement on page 71, which I will quote. Speaking of the SW 6" achromat the book states with regard to its "superior resolving power", that " At 150x, You can glimpse detail in the Jovian atmosphere that a 4-in, however good, could never unravel."

Rubbish!

Why? Because what the 6" gains in theoretical resolution it loses in its lack of definition and contrast.  The CA, coupled with the almost always relatively poor figure on the SW achro's can never match the definition and contrast produced by a top class 4" apochromat with its superior colour correction, light transmission, coatings and optical finish. It has little to do with 6" vs 4" but rather about optical quality. In the 6" F8 SW achro, the CA, though not objectionable for DSO work, is sufficiently bad, so that it smears the more intricate detail and delivers a false colour view of the planets. Saturn will appear whiter and sharper in a Vixen fluorite for example, its ring system will not only reveal their main components, A, B and C as well as Cassinis division, but far more intricate detail more akin to the grooves of a gramophone record viewed from an angle. Mars, when high in the sky will reveal such a wealth of detail  it would be impossible to sketch it all due to its complexity, and Jupiter is likewise mind blowingly detailed and way too complex in real terms to record accurately by sketching. The 6" SW achromat by comparison will always lose the battle in a planetary shootout against a good 4" apochromat.

Mike

 

[t0nedude]

On 3/1/2016 at 01:00, mikeDnight said:

I've had three Taks to date, the first a FS128, which was big for a 5" frac and it needed at least a GM8 to mount it well. I then bought a FS152, which was even more massive and required a G11. They were both superb instruments but the bigger they became, the less I used them. Eventually I sold the 152 after my back gave way as I was lifting it onto the G11, which was mounted on a pier in my garden, and stood about 7 feet off the ground. At the time I took planetary observing really seriously and preferred looking directly through the refractor.

I decided I wanted to get a scope that would be more of a pleasure than a chore to use, so foolishly I believed the advert in S&T that stated "It Is What You Want It To Be"! and bought a NP101. It was a beautiful rich field refractor but it wasn't pure like the Tak's, and its planetary performance was not in the same league. I sold it a year later!

Enter the ED120! I bought a 120ED Pro which was an excellent all round performer. I later part exchanged it for an Equinox 120ED, as paulastro assured me that the writing on the lens cell travelled all the way through the tube just like Blackpool Rock. I think he lied! However I used the ED120 for six years or more before Tak reintroduced fluorite into their scopes. Eventually I just had to have one.

On the first night I looked through the FC100D I knew I'd made the right decision. In side by side comparison with the120 ED the Tak was noticeably better at revealing planetary detail on Jupiter, so much so in fact that I actually exclaimed WOW! as I saw the intricacy of the belts in the Tak. Despite the greater theoretical resolution of the 120 ED, it didn't reveal the same level of detail. It wasn't that the 120 was a poor scope, it was superb, and had on many occasions whopped the socks of much larger scopes on the moon and planets; but the little Tak just had defining ability and a vibrance that, although subtle, was not evident in the ED.

Over the last year the FC100 has almost never failed to impress me with its planetary performance. It takes power well, so well in fact that I've been able to use X474 on Venus and the moon, and have razor sharp, colour free views. 

On DSO's, the fluorite lens seems to perform well beyond its aperture class, as I've been able to detect the subtle nebulosity around the Pleiades like I've never seen in any scope irrespective of aperture. The flame nebula and IC434 extending down from Alnitak could be detected without the use of a nebula filter. Binary stars are great to observe in the FC and somewhat difficult targets like the E and F stars in the trapezium become observable with careful study on a steady night.

The FC100D is a great scope that punches well above its weight, but it's not immune to bad seeing, and it is still subject to the laws of physics. With good eyepieces and good diagonal though it will revitalise your observing as it is so lightweight and easy to mount and makes for a great grab and go set up. For many it would be all the telescope they'd ever need.

Mike

My one and only post here, as this sort of topic really irks me for some reason, and I can't help but respond this once. You get all these refractor 'experts' or aperture snobs and wonder why refractors can frequently outperform telescopes of much larger apertures on all but the best nights on planets? And yet I very rarely see this mentioned, let alone it's value being noted especially being so important for certain observations. You want to know why the FC100D outperformed the larger 120ED? C.O.N.T.R.A.S.T.  Something the FS series (having one myself) are legendary for, and for good reason.  Contrast on the planets is more important that resolution limits for pulling out fine filamentary details.  It has been noted more than once that Fluorite doublets in field tests versus newer triplets (inc. but not limited to other Taks) show better contrast than said triplets.

[John]

Not many snobs or self appointed experts on this forum thank goodness. Just friendly folks who like to share their experiences