Tak FC-100 - a few questions :)

[Piero]

I am considering this telescope as a step up from my TV60.   The dilemma is DC or DF, and so this thread.

Briefly, I want the option to use my 2" equipment (in particular filters). This would make the choice rather easy: DF version.  

As often happens we then have doubts... can we get better for a life-time scope?     

The DC is noticeably lighter than the DF (~0.7kg less).  

 

Strategy 1 - DC with adaptor:

1a. Is it convenient to get the DC model and separately buy the adaptor for 2" equipment? (if I am not wrong, this is the same of the 76DC).

2b. What is the clear aperture for this adaptor?

 

Strategy 2 - DC and replace the standard focuser with a FeatherTouch:  

2a. What are the weights for the DC standard focuser and the FT focuser? or in another way, what is the weight of the DC with the FT focuser installed?

2b. Is this (https://www.firstlightoptics.com/starlight-instruments-feather-touch-2inch-crayford-focusers/2-crayford-focuser-for-takahashi-fs60-and-fc76.html ) the compatible FT focuser ? 

2c. What are the draw-tube lengths for the FC-100 DC and FC-100 DF ?  

 

Strategy 3 - DF

3a. Do these eyepieces reach focus without 2" extension tube? (Ethos 21mm, 31mm Nagler, ES30mm 82)

3b. Does the TV 24mm Panoptic reach focus using a 1.25" diagonal? 

 

 

More general questions:

a. Apart from aesthetic tastes, what are the pros and cons of getting a cradle or tube rings? 

b. Where did you buy your Tak in the UK? 

 

Any suggestion / consideration / experience is welcome of course! 

Thanks a lot,

Piero

Edited July 22, 2017 by Piero

[Cjg]

I'm watching his thread with interest Piero!

My Tak 76 is two years young, and I've often wondered what the 100 would be like. 

Came from Ian King, who was excellent to deal with, if i do buy the 100 (probably next year), I'd use Ian again without hesitation.

Chris

[John]

I bought my FC-100DL from Ian King and met him in person at a show a few months later. Seemed a top chap

 

[Alien 13]

I am a bit shocked, are TAKs that bad that you have to upgrade/modify them?

Alan

[Piero]

9 minutes ago, Alien 13 said:

I am a bit shocked, are TAKs that bad that you have to upgrade/modify them?

Alan

I don't think so.  

The reason why I thought about upgrading the focuser is due to weight essentially. If the FT weighs 0.5kg less than the DF focuser, I'd be interested. The move would cost about £200 on top of the DF model. 

[GavStar]

I started with strategy 3 and bought an FC100DF but have now replaced the focuser with a feathertouch crayford (I ordered it from flo and you need to specify that you want the adapter for the FC100 since I think it is different from the fc76). So starting from scratch I would now go for Strategy 2.

I tried the mef-3 Tak fine focuser but prefer the feathertouches on my other telescopes and hence in the end changed to a full feathertouch and have not regretted it.

i haven't weighed my scope with the feathertouch installed but seems pretty light to me, lighter than when it was a DF!

Drawtube lengths for DF and feathertouch are similar at 2.5 inches but I have needed to buy a 2 inch extender (I chose a Televue one but can use any I guess) to get enough back focus for my diagonal.

My DF did reach focus with ethos eyepiece since it has a bit more extension built into it than the feathertouch.

i have used Ian king and trutek to buy Tak telescopes and both have been excellent.

i prefer the parallax 95mm tube rings to the Tak cradle since it just feels a bit more secure to me but I think it's just personal preference.

Fantastic scope!!

[GavStar]

37 minutes ago, Alien 13 said:

I am a bit shocked, are TAKs that bad that you have to upgrade/modify them?

Alan

No but they don't tend to come with fine focusers and I find that I need one for high magnification viewing. Also Tak focusers do have a bit of a marmite reputation. In fact a few years ago Tak offered the tsa102 and tsa120 with a feathertouch focuser rather than a Tak focuser which potentially indicates even Tak recognise for some people a feathertouch makes sense.

[Piero]

Thanks for very informative feedback GavStar!

When you have a chance, could you let me know the weight of your Tak with FT and without accessories (rings, finder, etc), please? 

[Piero]

Just for completeness.

According to this http://starlightinstruments.com/store/index.php?route=product/product&product_id=405 the FT focuser is FTF2025BCR and the adapter is A20-304 (Scope specific tube adapter for TAKAHASHI FS78/ and all versions of the FC100 Telescopes). 

FTF2025BCR Focuser specs: 
Draw Tube Travel    2.5"/63.5MM
Lifting Capacity    8-10 pounds
Reduction Ratio    10:1
Draw Tube Drive Mechanism    Crayford
Weight of focuser    1.218 pounds
Racked In from Mounting Face    1.405"/35.687MM
Racked Out from Mounting Face    4.005"/101.727MM

(source: http://starlightinstruments.com/store/index.php?route=product/product&product_id=53)

Edited July 22, 2017 by Piero

[Stu]

I went for the DC version as I have never really rated Tak focusers and always intended to fit a FeatherTouch. I have the FT2025-BCR, same as you are considering. There is a lightweight LW version which saves a little weight but on balance I would stick with the full version for the 100. The LW suits the 60 and 76 scopes well.

I chose tube rings rather than the clamshell because I found the clamshell a little more bulky and perhaps heavier (need to check that out). I felt that they would also hold the scope more solidly being spread out more but this is perception rather than any hard fact.

I can probably weigh the scope tomorrow if that helps.

I too need an extension tube to get focus if not using binoviewers but I quite like the flexibility.

It's a lovely scope, very portable and I think you might just notice the difference vs the TV60  

[paulastro]

Piero, I have the DL (as you can probably see ) and have used mikeDnight's DC.  Mike, I'm sure, will probably post some useful info on the DC when he reads your post .

Just a few points.  Mike's  DC has the 2inch adapter, which does what it's supposed to.  I'm not sure if you'll have focusing difficulties with it and the different eyepieces you mention, but the focus travel of the DC is very short and I would choose the DF over the DC for that reason alone.

Re the choice between the tube clamp and rings, personally I'd go for the clamp anytime.  I think it wonderful, and it's very easy to rotate it within the clamp, and re-balance the scope by sliding it through the ring. It can be done quickly and easily and it is very easy to tighten the bolt which is large and easy to grip. In my view the Tak clamp is FAR superior to any tube rings I have ever used. 

Mike has the micro focuser and it works well, but I wouldn't buy it!!  The reason is, there is an alternative that is far cheaper.  I was looking for a good prism diagonal and bought the Baader T2 prism diagonal which comes packaged with a 1.25 nose piece (2 inch available as an extra for versatily).  At the other end it comes with a 1.25 eyepiece holder with compression fitting with three screws AND a helical focuser built in as well!  I didn't buy it for the helical focuser but it really is excellent in use as is the diagonal as well - with the added advantage of the T2 fitting and the versatility it brings.  I actually prefer the helical to the Tak micro focuser and the price for the whole thing - £106.  A bargain which ever way you look at it in my view!

http://www.rothervalleyoptics.co.uk/baader-prism-diagonal-t-2-90-with-focusing-eyepiece-holder-and-125-nosepiece.html

I'm sure you'll be really delighted with any of these two scopes Piero, so it's a win-win situation in my view.  Regards, Paul

 

[Piero]

Thanks @Stu and @paulastro !   Very helpful comments! 

[Piero]

9 hours ago, paulastro said:

I'm not sure if you'll have focusing difficulties with it and the different eyepieces you mention, but the focus travel of the DC is very short and I would choose the DF over the DC for that reason alone.

Thanks for sharing your opinion on this. That's my concern too. As far as I understand the DC has approx 25-30mm travel, whereas the DF has 68.6mm (2.7").
The Zeiss zoom is the eyepiece of my set that require more inward focus when used in 1.25" mode. It still reaches focus in my TV60 though. 

The 1.25" eyepiece requiring more outward travel in my 1.25" set is the 24 Pan.

Does anyone know if the 24 Pan reaches focus with the DC using a 1.25" diagonal?

Edited July 23, 2017 by Piero

[Stu]

6 hours ago, Piero said:

Thanks for sharing your opinion on this. That's my concern too. As far as I understand the DC has approx 25-30mm travel, whereas the DF has 68.6mm (2.7").
The Zeiss zoom is the eyepiece of my set that require more inward focus when used in 1.25" mode. It still reaches focus in my TV60 though. 

The 1.25" eyepiece requiring more outward travel in my 1.25" set is the 24 Pan.

Does anyone know if the 24 Pan reaches focus with the DC using a 1.25" diagonal?

I can check some of this soon Piero, should be using mine in the next night or so. I'm currently using a T2 BBHS diagonal which will have a longer optical path than 1.25" but still it needs extensions in the FT.

It depends upon your requirements though. For me what is most important alongside weight is minimum length for travel. I'm not bothered about needing to use an extension, it just becomes part of the drawtube and causes no issues. Of course more travel is always nice and makes life easier  but all these things are compromises and you pick the one that matches your criteria best. The FT just has such a lovely feel and control to it which really improves my enjoyment of the scope.

[jabeoo1]

11 hours ago, Piero said:

..............

2c. What are the draw-tube lengths for the FC-100 DF ?  

 

Strategy 3 - DF

3a. Do these eyepieces reach focus without 2" extension tube? (Ethos 21mm)

 

I can help you with the DF questions Piero.  I will set it up tomorrow and see what the situation is.  I now use a 2" mirror diagonal with a 17mm Ethos which is parfocal with the 21 mm according to Televue. 

[jabeoo1]

10 hours ago, Alien 13 said:

I am a bit shocked, are TAKs that bad that you have to upgrade/modify them?

Alan

I personally really love the stock focuser even at high power.   

[mikeDnight]

8 hours ago, Piero said:

 

The 1.25" eyepiece requiring more outward travel in my 1.25" set is the 24 Pan.

Does anyone know if the 24 Pan reaches focus with the DC using a 1.25" diagonal?

Yes it does! ☺

[mikeDnight]

9 hours ago, paulastro said:

Piero, I have the DL (as you can probably see ) and have used mikeDnight's DC.  Mike, I'm sure, will probably post some useful info on the DC when he reads your post .

Just a few points.  Mike's  DC has the 2inch adapter, which does what it's supposed to.  I'm not sure if you'll have focusing difficulties with it and the different eyepieces you mention, but the focus travel of the DC is very short and I would choose the DF over the DC for that reason alone.

Re the choice between the tube clamp and rings, personally I'd go for the clamp anytime.  I think it wonderful, and it's very easy to rotate it within the clamp, and re-balance the scope by sliding it through the ring. It can be done quickly and easily and it is very easy to tighten the bolt which is large and easy to grip. In my view the Tak clamp is FAR superior to any tube rings I have ever used. 

Mike has the micro focuser and it works well, but I wouldn't buy it!!  The reason is, there is an alternative that is far cheaper.  I was looking for a good prism diagonal and bought the Baader T2 prism diagonal which comes packaged with a 1.25 nose piece (2 inch available as an extra for versatily).  At the other end it comes with a 1.25 eyepiece holder with compression fitting with three screws AND a helical focuser built in as well!  I didn't buy it for the helical focuser but it really is excellent in use as is the diagonal as well - with the added advantage of the T2 fitting and the versatility it brings.  I actually prefer the helical to the Tak micro focuser and the price for the whole thing - £106.  A bargain which ever way you look at it in my view!

http://www.rothervalleyoptics.co.uk/baader-prism-diagonal-t-2-90-with-focusing-eyepiece-holder-and-125-nosepiece.html

I'm sure you'll be really delighted with any of these two scopes Piero, so it's a win-win situation in my view.  Regards, Paul

 

I can't really add much to what Paul says above, except that if you decide to use a 2" diagonal, you might consider getting one with a low profile 2" to 1.25" adapter giving more in-focus. As regards the Tak micro focuser, it is a very nice piece of kit but its expensive. The Baader prism with helical focuser is cheaper to buy but is superb both in quality and as a precision micro focuser. 

 

[Piero]

@mikeDnight 

Thanks a lot Mike!  really useful information. I will keep this in mind for the future.

 

@jabeoo1 

Thank you very much for your help! If this doesn't take too much time, would it be possible for you to measure the travel distance to reach focus with a 1.25" diagonal and a 24 Panoptic (or any other 1.25" TV eyepiece - I can then calculate for the 24Pan using the TV website), please?

Edited July 23, 2017 by Piero

[Piero]

2 hours ago, Stu said:

I can check some of this soon Piero, should be using mine in the next night or so. I'm currently using a T2 BBHS diagonal which will have a longer optical path than 1.25" but still it needs extensions in the FT.

It depends upon your requirements though. For me what is most important alongside weight is minimum length for travel. I'm not bothered about needing to use an extension, it just becomes part of the drawtube and causes no issues. Of course more travel is always nice and makes life easier  but all these things are compromises and you pick the one that matches your criteria best. The FT just has such a lovely feel and control to it which really improves my enjoyment of the scope.

@Stu

Thank you a lot!

Out of curiosity, do you need to minimise the length for travel because of binoviewer and Baader Solar wedge?

[Stu]

11 minutes ago, Piero said:

@Stu

Thank you a lot!

Out of curiosity, do you need to minimise the length for travel because of binoviewer and Baader Solar wedge?

It's mainly a practical thing, just trying to keep everything as light and short as possible for travelling.

The Herschel Wedge works no problem without an extension despite the huge barlowing I do with it!

I do need to try to see if I can reach focus with the BVs natively for DSO observing. I can connect via a short T2 adaptor to my diagonal so might be able to.

EDIT I will try to show the FT next to the Tak focuser (which I took off and never used!)

[jabeoo1]

6 hours ago, Piero said:

Thank you very much for your help! If this doesn't take too much time, would it be possible for you to measure the travel distance to reach focus with a 1.25" diagonal and a 24 Panoptic (or any other 1.25" TV eyepiece - I can then calculate for the 24Pan using the TV website), please?

Sorry no longer have a 1.25 " diagonal & the only 1.25" EP I have is the Nagler Zoom (probably not a useful comparison).  I previously used 1.25" mirror diagonals with Televue Plossls in the DF & they worked very well within the range of the draw tubes travel without the extension.  A 1.25" prism diagonal needed a small extension to gain back focus if I remember rightly.  

I don't like using the extension tube but instead use of a 2" Baader clicklock 47mm extension in the 2" diagonal to both gain back focus & improve the locking mechanism for the heavy 2" EP's.   

[Piero]

6 minutes ago, jabeoo1 said:

Sorry no longer have a 1.25 " diagonal & the only 1.25" EP I have is the Nagler Zoom (probably not a useful comparison).  I previously used 1.25" mirror diagonals with Televue Plossls in the DF & they worked very well within the range of the draw tubes travel without the extension.  A 1.25" prism diagonal needed a small extension to gain back focus if I remember rightly.  

I don't like using the extension tube but instead use of a 2" Baader clicklock 47mm extension in the 2" diagonal to both gain back focus & improve the locking mechanism for the heavy 2" EP's.   

Thank you!  You provided me with great information!

The TV Nagler zoom, 1.25" TV plossls (8-32), and 24 Pan are nearly parfocal. They all belong to the group B (http://www.televue.com/engine/TV3b_page.asp?return=Advice&id=81). I will use the 1.25" TV everbrite diagonal in the short term. The 24 Pan on this should come to focus without extension tubes then.  

[jabeoo1]

1 minute ago, Piero said:

Thank you!  You provided me with great information!

The TV Nagler zoom, 1.25" TV plossls (8-32), and 24 Pan are nearly parfocal. They all belong to the group B (http://www.televue.com/engine/TV3b_page.asp?return=Advice&id=81).

Thats handy, well I will double check the zoom in the 2" diagonal for you anyway to see where in the travel range it comes into focus.  I will post my findings tomorrow.   Thinking about it, the light path in a 2" diagonal is no different to the light path in a 1.25" diagonal?  Just the free aperture?  I may be wrong!

1 minute ago, Piero said:

Thank you!  You provided me with great information!

I will use the 1.25" TV everbrite diagonal in the short term. The 24 Pan on this should come to focus without extension tubes then.  

It should do with no issue. 

[ollypenrice]

For visual use I rather like the clamshells. They are quick to open and close and give lots of fast and easy fore-and-aft travel for balancing. (They might come up second hand because some imagers have found them not to hold the tube in perfectly constant alignment, which can spoil the guiding. This is not an issue in visual observing.)

I have also found Ian King to be an excellent retailer.

Olly