Takahashi FC100 f7.4 vs f9

[Stu]

1 minute ago, F15Rules said:

Nah, its the extra 2mm that does it! :-)

Dave

??

I was tempted by a TSA102, but recent views with my scope are giving me all I want, plus the convenience of lightweight/fast cool down. I'm sure the TSA102 is lovely, but doubt it gives dramatically different views under most normal conditions. I actually prefer the slightly shorter focal length, in fact one scope on my wish list is an APM LZOS 105 f6.2....

[mikeDnight]

2 hours ago, dweller25 said:

 

I can honestly say the FS128 is not top of my wish list

 

 

It is beautiful though Dave. I really wish I could turn the clock back and not exchange my 128 for the 152. Just one of my many mistakes! I loved the 128 but never felt the same way about the 152. I tried to buy it back a few months later but was told it had been sold to someone in Germany. I then decided I'd buy a TOA 130 but was told by the supplier, a trustworthy friend, that they are not as good as the FS 128. the 128 really is a keeper!

Mike ?

[Stu]

39 minutes ago, F15Rules said:

Er..since when has THAT ever stopped us Stu??:-)

Dave

Very true Dave. If one came up I would probably do my best to get hold of it, even though it would mean selling plenty of other kit. How much do they go for?

[F15Rules]

Well, just looking at UKABS archives, there aren't many in the past 7 or 8 years as you might expect. But apart from one with damaged coatings that was on at £1500, most seem to have been between c £2k and £3k..not so bad if you can get good provenance and test it out first? ( I understand that Fluorite is a brittle, somewhat unstable material that can damage easily if not handled with great care).

By all accounts just a wonderful scope:-)

Dave

[GavStar]

This discussion has helped me to work out what are the key requirements for me. In that regard I should have something arriving next month! 

Regarding binoviewers, I've just started using them this year and have been very impressed - best views ever of Jupiter for me. They are a bit fiddly and add weight to the set up but with the right eyepieces give a very comfortable and detailed view. Getting the right magnification is not always straightforward but other than that it's been a great success. And has also meant I'm no longer interested in giant binoculars.

[Stu]

20 minutes ago, Gavster said:

This discussion has helped me to work out what are the key requirements for me. In that regard I should have something arriving next month! 

Regarding binoviewers, I've just started using them this year and have been very impressed - best views ever of Jupiter for me. They are a bit fiddly and add weight to the set up but with the right eyepieces give a very comfortable and detailed view. Getting the right magnification is not always straightforward but other than that it's been a great success. And has also meant I'm no longer interested in giant binoculars.

Don't keep us in suspense Gav!! ?

[GavStar]

Fair point Stu! I was being a bit cryptic since it's not completely sorted but I hope to receive one of the last new FC100DLs. Your comments made me realise that lightweight and quick cool down are important to me hence I went for this rather than the TSA120. I like planets a lot and also have read that prism diagonals and binoviewers are better in higher focal lengths, hence the F9 spec has swayed me. Also if I wait I don't think I will have another opportunity to get a new DL - if I don't like it (unlikely I hope) I should be able to sell it relatively easily. 

Hopefully I can report on a side by side in May - it will probably be marginal as you said earlier.

[John]

Thanks for sharing your decision process - sounds a great choice

 

[Stu]

52 minutes ago, Gavster said:

Fair point Stu! I was being a bit cryptic since it's not completely sorted but I hope to receive one of the last new FC100DLs. Your comments made me realise that lightweight and quick cool down are important to me hence I went for this rather than the TSA120. I like planets a lot and also have read that prism diagonals and binoviewers are better in higher focal lengths, hence the F9 spec has swayed me. Also if I wait I don't think I will have another opportunity to get a new DL - if I don't like it (unlikely I hope) I should be able to sell it relatively easily. 

Hopefully I can report on a side by side in May - it will probably be marginal as you said earlier.

Nice one Gav. I'm sure it won't disappoint but I look forward to hearing about it assuming all goes to plan. A side by side would be very interesting, we all have to make assumptions alot of the time but they may well be wrong!

[mikeDnight]

5 hours ago, F15Rules said:

Well, just looking at UKABS archives, there aren't many in the past 7 or 8 years as you might expect. But apart from one with damaged coatings that was on at £1500, most seem to have been between c £2k and £3k..not so bad if you can get good provenance and test it out first? ( I understand that Fluorite is a brittle, somewhat unstable material that can damage easily if not handled with great care).

By all accounts just a wonderful scope:-)

Dave

I think I remember the one with allegedly damaged coatings being for sale. It would be really difficult  to damage the coatings on a FS refractor as they are seriously tough. Tak  used a special hard coating on the FS as it was a Fraunhofer  design and had the fluorite element at the front. I'm sure Takahashi wouldn't risk their reputation by placing an easily damaged fluorite lens in harm's way, unless it was tough enough to handle it. I think much of the talk regarding the fragility of fluorite is little more than scaremongering  by those having a vested interest in alternative  designs. I cleaned my FS 128 many times using isopropil alcohol  and it remained in immaculate  condition until I sold it years later. The only reason I cleaned it was to remove the inevitable  dew stains. I wouldnt be surprised  if the FS with the damaged lens had nothing more than dew stains on it. If dew forms on the lens its best just to leave the lens cap off and allow the moisture to evaporate  naturally at room temperature. If its capped wet then stains will build up and fungal growth may also occur in time.

The new FC100D must NEVER be cleaned using alcohol as it WILL damage the coatings. It won't damage the fluorite element though as that is situated behind the first element in a Steinheil design.

Mike 

 

[John]

Anyone know if the FS128 SV (short version) is OK to use in "cyclops" mode with a suitable extension tube ?

[Stu]

43 minutes ago, John said:

Anyone know if the FS128 SV (short version) is OK to use in "cyclops" mode with a suitable extension tube ?

Did you find one John? ??

[mikeDnight]

22 hours ago, Gavster said:

Fair point Stu! I was being a bit cryptic since it's not completely sorted but I hope to receive one of the last new FC100DLs. Your comments made me realise that lightweight and quick cool down are important to me hence I went for this rather than the TSA120. I like planets a lot and also have read that prism diagonals and binoviewers are better in higher focal lengths, hence the F9 spec has swayed me. Also if I wait I don't think I will have another opportunity to get a new DL - if I don't like it (unlikely I hope) I should be able to sell it relatively easily. 

Hopefully I can report on a side by side in May - it will probably be marginal as you said earlier.

There was a DL on sale at AstroFest and the guy who bought it said, after first light, that it gave him the best view if Jupiter he'd ever had in any scope regardless of aperture. That's high praise from a man who owns several other top end apo's, including a TOA  130 and a Tec 140, and is an experienced visual observer for several decades. The chances of you not liking it are pretty slim I think! 

Mike

[t0nedude]

On 4/19/2016 at 09:20, dweller25 said:

 

I can honestly say the FS128 is not top of my wish list

 

 

It's posts like this that make me glad I kept hold of my (mint condition) FS128 (bought new from Nick Hudson - True Technology) from 1999.

 

Tony.

[AstroSylv1]

Interesting read that I have just discovered... now, has anyone compared the DF/DC to a DL ? And ? :-)

[John]

9 hours ago, disciplus55 said:

Interesting read that I have just discovered... now, has anyone compared the DF/DC to a DL ? And ? :-)

This is a bad google translation from Japanese to English but it may contain some data that is of interest. The data is from Takahashi:

https://translate.google.co.uk/translate?hl=en&sl=ja&u=http://www.takahashijapan.com/ct-news/news_150904_fc-100dl.html&prev=search

[Stu]

I suspect it's a bit of a case of horses for courses. In my mind they are outwardly similar, but quite different in their aims.

I'm sure the DL is a lovely scope, and in an ideal world I would love to have one. I would think that under good to excellent conditions you will see the difference in high power planetary views, or on tight doubles.

The 100D is more of a compromise, and ironically that's the reason I'm happy with my mine. Much of my observing is 'mobile', and on a small Giro-WR mount so the shorter tube which is theoretically airline portable, but at least more convenient to 'chuck' in the car is appealing. Also, the wider field of view is nice to have. The planetary views are still lovely, and remarkable for the size of scope.

Hopefully I'll get the chance to look through Gavster's DL side by side with the D at some point this season.

[AstroSylv1]

It's funny to see that Tak just got such a wide offer on such a short time for 4" (TSA 102, FC100D and FC100DL) where on the 120mm, there is only the TSA 120... I wonder if they are going to make us some 120 mm FC scopes :-)

[John]

1 hour ago, disciplus55 said:

It's funny to see that Tak just got such a wide offer on such a short time for 4" (TSA 102, FC100D and FC100DL) where on the 120mm, there is only the TSA 120... I wonder if they are going to make us some 120 mm FC scopes :-)

I think many are hoping for an FC 125 DL

 

[GavStar]

On 19 July 2016 at 21:26, Stu said:

 

Hopefully I'll get the chance to look through Gavster's DL side by side with the D at some point this season.

You will Stu! ?

[AstroSylv1]

Last night, during 3h, I compared my TSA 102 to the brand new FC100-DF of a friend of mine. On Jupiter quickly (with GRS transit !) before it was too low, Mars, Saturn and some close doubles, plus after that some deep sky... We both do only visual... couldn't tell any difference at all when magnification was the same, BUT when we arrived on site, his refractor was on temperature 15 minutes before mine, and is 1.5 kg or so... a real traveler solution. But visually only, really, impossible to see any residual CA in the FC100 (and not on the TSA of course), even at 300x on planetary. The only CA was the atmosphere one, or from the eyepieces, but since we both used some orthos, CA was absent from the eyepiece side.

So, all in all, good luck to see a difference between a DF and DL in visual only !!! :-)

[John]

Interesting report Sylvian

I'd have probably been interested in a TSA102 if the FC100DL had not been available. The FC100 vistually no cool down time though wheras the triplet certainly would. My Vixen ED102SS needs a good 30mins or so to deliver it's best quality images.

 

[F15Rules]

On 19/04/2016 at 09:20, dweller25 said:

 

I can honestly say the FS128 is not top of my wish list

 

 

Hi David

Is that a Tal tripod with Berlebach tray? Which Vixen mount is it? How does it handle the size of the scope?

Is it steady for visual?

Dave

[seiko]

You'd definitely see a difference visually between the FC 100 and TSA 120. I could see more detail with the TSA 120 compared with my FSQ 106 with or without an extender. You'd definitely notice the bulk/weight increase in going up to 120mm too from a 100mm. In terms of going up to the 130mm class, well it's a completely different experience weight wise but similar experience visually to the 120. My FSQ 130 weighs a lot (lot) more than my TSA 120 and offers slightly nicer views.

Each step up in size simply increases bulk, weight and cool down.

For me the TSA 120 represents the goldilocks of the range as although expensive it's so similar to the 102 in size and weight but has a far larger aperture it's a clear choice. As the FC100 is lighter it falls into a separate category and offers a very nice light weight scope.

 

 

 

[dweller25]

4 hours ago, F15Rules said:

Hi David

Is that a Tal tripod with Berlebach tray? Which Vixen mount is it? How does it handle the size of the scope?

Is it steady for visual?

Dave

Hello Dave,

It's a Vixen GP-DX head on a Berlebach UNI-28 tripod.

It handles the FS128 perfectly and has excellent stability when focussing at high power since I fitted the 10-1 Feathertouch focuser - that was not true when the Tak focuser was on though.