Takahashi FC-100 and FC-76 advice

[johnturley]

6 hours ago, Commanderfish said:

Has anyone got 1.5" travel on their Tak FC focuser drawtube, for instance from the shorter Feathertouch FTF 2015, and is it enough travel to bring your 2" Eyepieces to focus (Ethos, ES 82?) I know some of you have the FTF 2025 with 2.5" travel which seems ample. I gather the stock DC focuser is only 1" travel so the FTF 2015 would be a small improvement but not sure if it's enough?

To me 1" or even 1.5 " of travel is totally inadequate, I also find that the 45 mm of travel on my Explore Scientific Refractor to be inadequate, to me at least 3 " or 75 mm are needed. My Esprit 150 focuser has 85 mm of travel which provides sufficient in travel to reach focus with a 1.25" filter wheel, or an ADC, and sufficient out travel to reach focus with my longest focal length eyepiece, a Meade 56 mm Plossl eyepiece.

I had some thoughts of getting a Tak 100 DZ to provide a more portable instrument for holiday trips, does anyone know the amount of travel on the stock Tak focuser that comes with this model. 

John 

Edited April 2, 2021 by johnturley

[JeremyS]

10 hours ago, johnturley said:

 

I had some thoughts of getting a Tak 100 DZ to provide a more portable instrument for holiday trips, does anyone know the amount of travel on the stock Tak focuser that comes with this model. 

John 

You won’t like it John. Awful scopes those Taks with their poor focusers 

😊

[Commanderfish]

10 hours ago, johnturley said:

I had some thoughts of getting a Tak 100 DZ to provide a more portable instrument for holiday trips, does anyone know the amount of travel on the stock Tak focuser that comes with this model. 

John 

It's 1.2" for the DC and 2.5" for the DF and DZ with stock focusers

[JeremyS]

3 minutes ago, johnturley said:

Sorry should have said 100 DZ not DX, for some reason I appear to have lost the ability the edit posts, has anyone else got this problem, maybe an administrator can sort it for me.  

Click on the 3 dots at the top of your post you want to edit: same line as where it says Johnturly. You will get a drop down menu with an option “edit”

[johnturley]

12 minutes ago, Commanderfish said:

It's 1.2" for the DC and 2.5" for the DF and DZ with stock focusers

Thanks for the information 

[johnturley]

41 minutes ago, JeremyS said:

Click on the 3 dots at the top of your post you want to edit: same line as where it says Johnturly. You will get a drop down menu with an option “edit”

Thanks Jeremy, managed to do it ok, although can't delete my now superfluous post. 

I don't know when they changed the system, you used to get an edit and I think also a delete button until recently.

John 

Edited April 2, 2021 by johnturley

[HollyHound]

23 minutes ago, johnturley said:

To me 1" or even 1.5 " of travel is totally inadequate, I also find that the 45 mm of travel on my Explore Scientific Refractor to be inadequate, to me at least 3 " or 75 mm are needed.

I would agree that it’s nice to have tons of focuser travel... my own StellaMira 80mm f/10 has almost 100mm for example.

However, with the right combination of spacers/extensions, I’ve got my FC-76DCU setup now to use pretty much any of the eyepieces I have without having to change anything in a session. Of course I’m only doing visual and not using binoviewers or anything else in the system.

Ive also just received a 1.04x flattener and adaptors that should allow me to attach my EOS and do some basic photography, but that will require swapping the back end setup of course, but I’m fine with that 👍

[HollyHound]

15 minutes ago, johnturley said:

Thanks Jeremy, managed to do it ok, although can't delete my now superfluous post. 

I don't when they changed the system, you used to get an edit and I think also a delete button until recently.

John 

Modern user interface (UI)  design is trending towards “hiding” things away unfortunately, which looks lovely but is confusing too. They call it a “discoverable” UI 🤔😬

My ex boss (one of the co-founders of TomTom) always used to ask us to bring the UI to the minimum required to still be functional, but no further 👍

As Antoine De Saint-Exupery said... “Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away” 😃

Edited April 2, 2021 by HollyHound

[mikeDnight]

Don't forget that the FC100D's also have removable extension tubes on their focusers. Tak love to puzzle with their unnecessary engineering, but it does allow a potentially greater focuser/ eyepiece placement than the 2.5" draw tube movement would suggest. The greatest difficulty I found was with the DC focuser, the difficulty being not enough inward focus for some eyepieces with 2" diagonals. But there are ways around such problems.

[Commanderfish]

1 hour ago, mikeDnight said:

Don't forget that the FC100D's also have removable extension tubes on their focusers. Tak love to puzzle with their unnecessary engineering, but it does allow a potentially greater focuser/ eyepiece placement than the 2.5" draw tube movement would suggest. The greatest difficulty I found was with the DC focuser, the difficulty being not enough inward focus for some eyepieces with 2" diagonals. But there are ways around such problems.

Is one of the solutions to insufficient infocus on the DC with 2" diag to install a Feathertouch? Because that's the way I'm leaning...

Edited April 2, 2021 by Commanderfish

[Stu]

6 hours ago, Commanderfish said:

Is one of the solutions to insufficient infocus on the DC with 2" diag to install a Feathertouch? Because that's the way I'm leaning...

Yes, it does fix that problem. As Mike says, you can remove the front section of the Tak standard focuser and achieve the same thing, but the FTs are so nice, I’m sure you will want one 😀👍.

By the way, there are two FT adaptors which work on the DC. The A20-302 screws straight into the silver fitting at the back of the OTA and is the one Highburymark uses by the looks of it. This does allow the fitting of a finder by using a small OTA ring; that’s one disadvantage of the FTs, no finder shoe nor anywhere to fit them.

The other adaptor is the A20-304 which is the one I use. This requires the unscrewing of the silver fitting and it then screws directly onto the OTA. I believe it may be slightly shorter than the 302 but can’t remember. I think the 304 is officially the correct one for the scope but both do the same job, and some prefer retaining the silver fitting and the ability to fit the finder. I have a shoe mounted on one of the tube rings

[Commanderfish]

4 hours ago, Stu said:

Yes, it does fix that problem.

The other adaptor is the A20-304 which is the one I use. This requires the unscrewing of the silver fitting and it then screws directly onto the OTA. I believe it may be slightly shorter than the 302 but can’t remember. I think the 304 is officially the correct one for the scope but both do the same job, and some prefer retaining the silver fitting and the ability to fit the finder. I have a shoe mounted on one of the tube rings

That is marvelous info Stu! I like the silver ring and am going for silver OTA tube rings too. Sounds like the 304 adapter might give slightly more in focus than the 302 - does anyone know if using the 302 still gives enough in focus for most 2" EPs with a 2" diagonal?

[Stu]

1 minute ago, Commanderfish said:

That is marvelous info Stu! I like the silver ring and am going for silver OTA tube rings too. Sounds like the 304 adapter might give slightly more in focus than the 302 - does anyone know if using the 302 still gives enough in focus for most 2" EPs with a 2" diagonal?

Yes it does, I’ve had both and you have plenty of inwards focus with both, in fact you can end up needing extensions but that’s not a big problem. It makes binoviewing easy too.

[mikeDnight]

11 hours ago, Commanderfish said:

Is one of the solutions to insufficient infocus on the DC with 2" diag to install a Feathertouch? Because that's the way I'm leaning...

The feathertouch is a beautiful addition and no one would criticise you for fitting one to such a beautiful scope. But they aren't cheap, and so if cost is an issue, why not go for the DF with its better focuser over the DC? Still not as good as the feathertouch though, although a feathertouch can be added at any stage when finances allow.  To be honest, Takahashi have made an error by using the FC 60 focuser on the DC. It must be an issue they are aware of yet they haven't changed the design. With the DC focuser, if you use all Tak eyepieces you'll have no problems, and that's probably why they leave things as they are. But by shortening the tube and increasing the length of the draw tube, the " in travel" issue would be done away with.  As a purely visual observer though, I do find the DF/DZ focuser really quite good, and much nicer than any Crayford i've used.  

I use mainly 1.25" eyepieces and can attain focus across the entire range from 35mm down to 1.6 mm. Even when using my paired 35mm Eudiascopic/Ultima's in my binoviewer, without barlow or gpc, I can still reach focus. It's worth noting though that the Takahashi 1.25" prism has a significantly shorter light path than the 1.25" Baader prism, and so I'll sometimes need to change to the Tak prism to get the 35mm's to come to focus with my binoviewer. Hope this makes sense!

[Stu]

I found these pics which may be useful.

They show the original focuser vs FT. There is a removable section in the Tak focuser which gives more in focus (shown in image 2). Then there is the comparison between 304 and 302 adaptors (302 being the one which retains the silver ring). I needed a lot of extensions as I was using a 1.25” prism at the time, but you can see that a shorter on is needed for a 2” diagonal or nine for binoviewing. Hope that helps. These were Gavin and my FC100DCs when they ‘met’ at the pub 🤣

[Commanderfish]

20 minutes ago, Stu said:

I found these pics which may be useful.

They show the original focuser vs FT. There is a removable section in the Tak focuser which gives more in focus (shown in image 2). Then there is the comparison between 304 and 302 adaptors (302 being the one which retains the silver ring). I needed a lot of extensions as I was using a 1.25” prism at the time, but you can see that a shorter on is needed for a 2” diagonal or nine for binoviewing. Hope that helps. These were Gavin and my FC100DCs when they ‘met’ at the pub 🤣

 

 

That is super helpful Stu! 

So, the DC model will be available in a few weeks but the DF won't.be available til June. 

I am probably in the minority but I really don't like the Tak light green or even the new light blue, so a feathertouch is quite appealing. I do like the silver rings though. I can currently pick up a used FTF 2015 at a more reasonable price though that only has 1.5"/ 38mm travel. Still better than stock.

I've done some calculations using one of my exisiting fracs which shows I need 30mm travel to get all of my 2" EPs to focus (except one Kitakaru 45mm which I would be very unlikely to use with a 740mm FL scope anyway. This means that with 38mm travel and the right amount of extensions, I can get all of my 2" EPs to focus with an FTF2015.

The FTF 2025 is the recommended focuser for Taks but as far as I can tell the FTF 2015 should have the same fitment as it seems Starlight only have one range of adapters for all the FTF20xx focusers - does that make sense? Should work with an A20-302/304?

So the DF would be the most economical way to use all 2" EPs but I'd have to wait 3 months and I don't like the colours, the stock DC wouldn't quite have enough travel for all 2"EPs, the DC plus used FTF2015 would do the job but the DC with new FTF2025 would be most versatile at the highest price.

I'm tempted to get the DC and used FTF 2015. Thoughts?

[Stu]

Sounds good Dinesh. A DC with the used 2015 sounds like a very good solution. The FTF2015 will fit the same adaptors, that’s fine. I’m sure it will retain its value so if you find it’s a problem you could replace it with a 2025 in future with little loss. I’m sure it will just be a case of finding a suitable extension then the 1.5” travel will likely be sufficient.

[JeremyS]

If I were going for an FC 100, I’d go for the DZ. Further, for visual I’d save a few Bob and stick with the Tak focuser. Not sure how airline portable, but with the dew shield retracted and accessories removed the length is only 595 mm according to FLO website.

[Stu]

24 minutes ago, JeremyS said:

If I were going for an FC 100, I’d go for the DZ. Further, for visual I’d save a few Bob and stick with the Tak focuser. Not sure how airline portable, but with the dew shield retracted and accessories removed the length is only 595 mm according to FLO website.

That might be fine for more premium airlines Jeremy but I think 550mm is more realistic, plus it needs to fit inside the bag. All this comes down to personal preference really. I find the fine focuser invaluable for, well, fine focusing 😉. My 8” f8 has a decent single speed and I really would like to put a dual speed on it. I’m sure the DZ/DF focuser is better than the DC one though. I know you can add the Tak MEF but the FT end result is preferable in my eyes. That said, there is no NEED to change the focuser, it works perfectly well if looked after. I guess I’ve just come across a few that have been thrashed by imagers in the past and were pretty ropey.

[Highburymark]

Agreed Stu. The maximum cabin baggage size even with premium airlines like British Airways is 56cm length, so even 550mm will be touch and go - I think it probably needs to be 540mm or less. Takahashi are marketing the DZ as airline portable, but I’m not sure it is. It is however, a beautiful telescope! 

[HollyHound]

9 minutes ago, Highburymark said:

Agreed Stu. The maximum cabin baggage size even with premium airlines like British Airways is 56cm length, so even 550mm will be touch and go - I think it probably needs to be 540mm or less. Takahashi are marketing the DZ as airline portable, but I’m not sure it is. It is however, a beautiful telescope! 

This was part of my reasoning for getting the FC-76DCU now, as I can see a 100mm in the near future, and I'm thinking about the DZ when they become available again. So for now the 76 (and 60) give me travel options as well as being superb for grab and go around the farm here 🙂

However, I wasn't aware that a small extension could be removed on the 100DC, as that makes it usable for binoviewing too 🤔

Edited April 3, 2021 by HollyHound

[johnturley]

25 minutes ago, Highburymark said:

Agreed Stu. The maximum cabin baggage size even with premium airlines like British Airways is 56cm length, so even 550mm will be touch and go - I think it probably needs to be 540mm or less. Takahashi are marketing the DZ as airline portable, but I’m not sure it is. It is however, a beautiful telescope! 

I've also heard that the 100 DZ won't fit  within the cabin baggage requirements, despite Takahashi claiming that it does, and wonder whether I would risk putting one in hold luggage. I was thinking of getting one in time for the 2024 Mexico/USA total solar eclipse. 

John 

Edited April 3, 2021 by johnturley

[Highburymark]

2 minutes ago, johnturley said:

........wonder whether I would risk putting one in hold luggage.

Nooooooooooo!!

[mikeDnight]

I'm not a fan of retractable dew shields. If the shield is retracted over a cold wet tube, it can potentially introduce moisture into the lens cell if the shield is capped. So I'll often bring the fully extended DZ back into the house, allowing it to dry off naturally. Retractable shields aren't a game changer for me at least. And even the superb DZ, for me at least, isn't world's apart from any of the other FC's in the series. The best scope out of the bunch will be the one that's used most. They're all brilliant!

[mikeDnight]

I think if I needed to take an FC on a plane, I'd remove the focuser, and if a DC or DF, the dewshield too. It would just mean I'd need to find a suitable cap for the lens cell and open tube.