Takahashi FC-76DCU travel scope project.

[Mumia]

Hello, I would like to show off the recently completed "perfect" traveler scope project. About half a year ago I bought a super Tak 76dcu refractor, the main goal was to add to my stable of refractors, something that I can quickly grab under my arm and go out into the field or set up on the balcony. This small telescope really positively surprised me with the amount of detail it is able to show on the planets and the moon. Compared to the FS 102, which I also currently have, it produces much whiter images. His older brother has a tendency to drag the image slightly into yellow. Of course, not like ED scopes, but it is noticeable. However, in FC76dcu the moon looks so raw and super sharp as if it were made of concrete. The whites are as white as snow and the blacks are as dark as pitch. Tested on bright stars, it works almost perfectly. I wrote almost, because only with the cq 1.7 extender it's incredibly stunning. The diffraction disk is beautifully evenly distributed, showing virtually perfect levels of spherical correction.

In the project, I focused on ensuring that there were no bottlenecks, neither in the generated image nor in the mechanics.
The first purchase was Extender cq 1.7, which changes the F ratio from F/7.5 to F/12.5. I think I don't need to describe the obvious advantages in planetary/lunar observations that this modification gives. Next, I replaced the stock 1.25" focuser, which, without an extension, extends only 1 inch. The choice fell on Feather Touch FTF2025BCR with the A20-302 adapter enabling connection to OTA. Thanks to this, I can use 2" accessories without any problems and the adjustment is increased to 2.5".

I used a 2" BBHS prism as an diagonal. Silver-plated coatings + prism improve red transmission. I especially appreciate this in Jupiter observations, it beautifully brings out the salmon shades and browns inside the belts. The whole thing is suspended on a lightweight AZ GTI mount and Benro carbon legs.
 

All that's left is to replace the clamps so I can add a finder and that's it

Now I'm going to the balcony to admire the moon.

Best regards,  Chris

Edited February 27 by Mumia

[JeremyS]

That’s a very fine scope you have there.

It’s often claimed that the FS 102 is a Mars killer, perhaps due to the optical qualities you describe. I’ve not compared my FS 102 side by side with my FC 76DCU ( or FC 100DZ for that matter), but I had some of my best ever views of Mars with the FS 102, during its 2003 perihelic opposition.

[Nicola Fletcher]

Thanks for posting details of your setup. I agree that the FC76-DCU is a very special scope and a wonderful travel scope too. 
I am planning on adding the CQ 1.7x extender to mine at some stage, and I think the longer scope looks very classy with the extender. I use mine as a super portable setup and take it all over the world, so I haven’t felt the need to change the focuser, and I usually pack a 1.25” Tak prism diagonal and three eyepieces, together with a simple red dot finder. This keeps it as lightweight as possible.  
I love the versatility of this great little scope that gives such fantastic views for its aperture.

[IB20]

I love my 76Q. Still amazes me how much a 3” scope can show, like you say, it’s an astonishingly good lunar and planetary scope. 🤗

[Mumia]

Recently I also found such a setup made by a guy from CN. Double extender cq 1.7 giving F/21.6 😅

[JeremyS]

3 minutes ago, Mumia said:

Recently I also found such a setup made by a guy from CN. Double extender cq 1.7 giving F/21.6 😅

With a setup like that I can understand why his Questar remains on the shelf 😊

[DirkSteele]

Preaching to the choir on this!  Reviewed it both base unit and with the CQ module and it is fab.  Great travel scope which has been to Africa many times including my honeymoon (understanding wife!)

 

The Q review on my site.

http://alpha-lyrae.co.uk/2018/12/07/takahashi-fc-76q-review/

The orginal review on my site before Astronomy Now were short a review and I reworked it.

http://alpha-lyrae.co.uk/2017/03/12/takahashi-fc-76-dcu-review/

 

And it means you can do this with it......

Edited February 27 by DirkSteele
typo

[The60mmKid]

13 minutes ago, DirkSteele said:

Preaching to the choir on this!  Reviewed it both base unit and with the CQ module and it is fab.  Great travel scope which has been to Africa many times including my honeymoon (understanding wife!)

 

The Q review on my site.

http://alpha-lyrae.co.uk/2018/12/07/takahashi-fc-76q-review/

The orginal review on my site before Astronomy Now were short a review and I reworked it.

http://alpha-lyrae.co.uk/2017/03/12/takahashi-fc-76-dcu-review/

 

And it means you can do this with it......

I've read your review several times over the years with great interest. (I'm a fan of your reviews, in general!) I'm curious whether you still feel the same on the following point or whether your perspective has changed any since writing the review: 

"While I have been unable to convince myself that the scope actually sharpened up performance on the planets and double stars, from the already impressive base FC-76, the last residual false colour seen on the most challenging of objects is eliminated, and the truly flat field, even to my accommodative eyes, means large open clusters and the Moon really do impress... Even though the CQ module is “only” £301, which is cheap for Takahashi, I am not sure I would recommend purchasing the module if it is only for use with the FC-76 DCU as I did not see enough additional benefit to really justify the expense."

The way I read your comments is, "The extender does improve things, but not significantly enough for me to recommend it." Your assessment, along with Roger Vine's (which is more explicitly in favor of the extender) are ones I keep mulling over.

Edited February 27 by The60mmKid

[IB20]

Oh go on then… a cracking early evening admiring Venus on the Starbase AZ. Absolutely perfect views and completely colour free.

😍

[DirkSteele]

12 minutes ago, The60mmKid said:

I've read your review several times over the years with great interest. (I'm a fan of your reviews, in general!) I'm curious whether you still feel the same on the following point or whether your perspective has changed any since writing the review: 

"While I have been unable to convince myself that the scope actually sharpened up performance on the planets and double stars, from the already impressive base FC-76, the last residual false colour seen on the most challenging of objects is eliminated, and the truly flat field, even to my accommodative eyes, means large open clusters and the Moon really do impress... Even though the CQ module is “only” £301, which is cheap for Takahashi, I am not sure I would recommend purchasing the module if it is only for use with the FC-76 DCU as I did not see enough additional benefit to really justify the expense."

The way I read your comments is, "The extender does improve things, but not significantly enough for me to recommend it." Your assessment, along with Roger Vine's (which is more explicitly in favor of the extender) are ones I keep mulling over.

That is a really interesting question.  I am not sure I have changed my mind, but I have to confess I have not used the 76Q many times as it just adds to the stuff you need to take away and it has become my defacto travel scope when going abroad.  The Q module tends to sit in the FS-60.  Perhaps I need to give it some more tries and see if my mind changes.  I read Roger's review as well (I like his stuff too) and noted he was a little more positive.  Certainly your interpretation of my comment was what I intended to say.

[Mumia]

10 minutes ago, IB20 said:

Oh go on then… a cracking early evening admiring Venus on the Starbase AZ. Absolutely perfect views and completely colour free.

😍

Color free is exactly the word that comes to my mind when I think about this refractor with this extender Venus and some particularly bright stars such as Sirius do show some very minor color fringing but when you add this magical addition you can easily forget about them.

[IB20]

I haven’t taken the Q module off mine, admittedly it’s not been anywhere exotic yet. As @Mumia states, it has removed the smidgen of colour that may have been there and now, I can’t believe a better 3” exists. I found having the increased mag range really helps for lunar, double stars and other targets that take higher magnification too. One target I noticed the most improvement on was Mars. It seemed to sharpen the disc up which helped picking out clearer albedo markings and polar cap distinction. I think Roger Vine’s review mentions this too.

[Stu]

Some relevant info in this thread where I compared the 76DCU and Q.

Not huge differences but noticeable nonetheless.

[Mumia]

So now let's brainstorm how to add a finder to this setup 😅 Maybe you could recommend some clamps that I can mount on the focuser?

[Stu]

I think @DirkSteele has used a small tube ring around the focuser to attach a finder to. You can see how he did it here:

http://alpha-lyrae.co.uk/2016/04/03/takahashi-fs-60-review/

I use MoreBlue Rings and just mount a finder shoe on top of those. It normally ends up on the side when I use an AltAz mount and works ok. You would think for the money Starlight would find a way to fit a finder shoe on!

[josefk]

I have no idea why small scopes tickle my fancy - it's irrational - but they do very much and i've enjoyed reading this thread. That's a nice execution of a 'grab and enjoy' set-up @Mumia (& everyone else posting theirs 👍)

[Stu]

Just as an aside, my CQ Extender normally lives on my FS-60, making it a Q as that’s where it makes most difference. I do love the 76Q configuration though. Comparison here, sorry if I’ve posted this one too much 😬

[josefk]

Is that 60Q, 76, 100 left to right @Stu or some other combination?

[Stu]

1 minute ago, josefk said:

Is that 60Q, 76, 100 left to right @Stu or some other combination?

Exactly that, 60Q, 76DCU and 100DC, left to right.

The 60 has a lightweight 2025 FT, the others the standard 2025BCR, really makes them complete in my eyes.

[Mumia]

2 hours ago, Stu said:

Just as an aside, my CQ Extender normally lives on my FS-60, making it a Q as that’s where it makes most difference. I do love the 76Q configuration though. Comparison here, sorry if I’ve posted this one too much 😬

Beautiful set of refractors. Every day you can hang something different on the mount, depending on the conditions and your mood. As for the FT focusers, they are truly a wonderful addition to these amazing telescopes. They are much better than those that come standard with the scope.

[The60mmKid]

Has anyone used a Baader Steeltrack focuser with their FC-76 or other Tak?

[Icesheet]

2 hours ago, Stu said:

Just as an aside, my CQ Extender normally lives on my FS-60, making it a Q as that’s where it makes most difference. I do love the 76Q configuration though. Comparison here, sorry if I’ve posted this one too much 😬

Apologies for hijacking your thread somewhat @Mumia. Lovely set up you have and one I am looking at in the future. 
 

I recently sold my Tak FS-60 with reducer. I had a feeling I might end up regretting it so I kept the Q extender, visual adapters and FT 2015BCR that I never got round to putting on the FS-60. My thinking was I could buy the 76DCU objective in the future and have a 76DCUQ on the ‘cheap’. However, looking enviously at the photo of@Stu scopes, I am struck by how little there seems to be size wise between the 76Q and FC100. I also didn’t know the 2” FT’s were compatible with the FC100. I’m now wondering if it might be worthwhile skipping the 76 altogether and jumping to the FC100. What’s the thoughts on the improvement of the FC100 v 76DCUQ on planetary and lunar? Would I miss much on portability and cool down time between the two?

[Stu]

23 hours ago, Icesheet said:

Apologies for hijacking your thread somewhat @Mumia. Lovely set up you have and one I am looking at in the future. 
 

I recently sold my Tak FS-60 with reducer. I had a feeling I might end up regretting it so I kept the Q extender, visual adapters and FT 2015BCR that I never got round to putting on the FS-60. My thinking was I could buy the 76DCU objective in the future and have a 76DCUQ on the ‘cheap’. However, looking enviously at the photo of@Stu scopes, I am struck by how little there seems to be size wise between the 76Q and FC100. I also didn’t know the 2” FT’s were compatible with the FC100. I’m now wondering if it might be worthwhile skipping the 76 altogether and jumping to the FC100. What’s the thoughts on the improvement of the FC100 v 76DCUQ on planetary and lunar? Would I miss much on portability and cool down time between the two?

I have travelled with both, and there are pros and cons to each. The FC100DC will go in carry on baggage but this requires removal of the dew shield and focuser. This is fairly straightforward to do and I normally then put the dew shield over the OTA with some protection between them to avoid scratching.

I normally split the 76 in two which in itself takes up two parts of my travel case so the main benefit becomes the weight. You can also just remove the dew shield and put it over the OTA so it fits into the central section so that is more compact than the 100DC. Obviously it is thinner too so more can be packed around it.
 

For info, weights and lengths are as below including MoreBlue rings and dovetail:

FC-100DC   3.5kg   62.5cm

FC-76DCU  2.1kg    53.5cm

FS-60Q       1.95kg  42.5cm

EDIT these were with the lightweight focuser on the 76, which is not how I normally have it. With the LW on the 60, the weights are:

FC-76DCU  2.25kg

FS-60Q       1.8kg

The 100DC needs the focuser and dew shield to be removed in order to fit in my Airport accelerator case, the 76DCU just needs the dew shield to be removed and of course the 60Q fits in fully assembled.

The 2” FTs work very well with, and suit all these scopes in my opinion. I find the 2025 is better with its longer travel range.

In terms of performance, they follow theory in my view ie you can see the differences between 60, 76 and 100. I think the 100 definitely shows more detail on planets and the Moon, and splits tighter doubles. The 76DCU or Q are fantastic for their aperture, but I don’t think the Q addition enable it to beat the 100.

[DirkSteele]

41 minutes ago, Stu said:In terms of performance, they follow theory in my view ie you can see the differences between 60, 76 and 100. I think the 100 definitely shows more detail on planets and the Moon, and splits tighter doubles. The 76DCU or Q are fantastic for their aperture, but I don’t think the Q addition enable it to beat the 100.

Agreed. Even a “perfect” 3” scope which one might argue the 76Q comes close to achieving will not outperform a 100mm scope that has been executed to the usual Takahashi quality, I.e excellent. That 24mm increase at this aperture makes a heck of a difference.

[JeremyS]

53 minutes ago, Stu said:

 so that is more compact than the 100DC. Obviously it is thinner too so more can be packed around it.

but fewer pairs of Speedos inside the tube