Tak FC-100DC vs Vixen FL102S on the Moon

[Stu]

I’ve been wanting to put these two side by side since getting the Vixen, and after sorting out my observing area and getting the Rowan AZ100 in a better place, I finally did it last night. The AZ100 performed beautifully on the Planet tripod once balanced correctly, which involved bring the Tak back quite a long way in its rings because of the lightweight prism and orthos. The slo mo controls are actually much quicker and easier to use than the handset on the Vixen GP, more intuitive to get the direction right and quicker skews. This more than offsets the loss of motorised tracking I think so I will use this setup for solar white light and Ha in future too. I’ve popped a couple of pictures of the solar setup in here for reference.

To try to keep things as fair as possible, I just used Baader Genuine Orthos, and rather handily a 5mm and 6mm gives x148 and x150 respectively (Tak then Vixen).

Originally I was going to use the Baader Zeiss T2 prism in the Vixen, and the Baader BBHS T2 Mirror in the Tak, but after an initial look and swap between scopes, I could see a definite benefit in the prism, a little sharper and more contrasty. What to do? I then tried my Tak Prism, which despite some recent comments to the contrary I find very good, and it levelled things up nicely so I felt it was now a fair fight. That in itself was a surprising finding, the mirror in the BBHS has recently been replaced so should be at top performance.

Initially I viewed with a 12.5mm and 9mm, but felt like the mag difference was too much for meaningful results, so switched to the shorter focal lengths and set to work.

I observed many different features, trying for threshold craters and rilles which I thought might separate the two. I looked at Plato craterlets, the Copernicus craterlets, detail on the sides of smaller crater walls, Messier and Messier A and domes. I wasn’t so worried about knowing the names of what I was looking at, just comparing the views.

The result? Under the fairly steady conditions I had last night, and at x150 mag, I was unable to separate them. On occasion I would switch from one to the other and think that the second one gave a worse view, but it was only ever down to seeing variations. When the seeing was the same, the views were the same.

My old favourite Izar showed identical, and beautiful views in both scopes. Perfect airy disks and diffraction ring, clear separation and colour difference between the two components.

The Double Double initially looked a fair bit better in the Vixen, and the faint star nearby did not show in the Tak. Curious? Yes, but problem solved by a quick defocus which showed the leaves of the hedge cutting into the Tak view! Once clear of this, the views were the same again.

I will try again with some tighter doubles when I get the chance to see if I can tease any differences out.

So, I have one old and one new scope, both 4” and both giving excellent performance. What to do? My only decision is to keep both! I love the look and character of the Vixen, and the portability of the Tak. The Vixen has the longer focal ratio and gets to x300 with the Nag Zoom vs x246 for the Tak which is useful on occasion. The Tak binoviews easily, the Vixen doesn’t seem to have the inwards focus, although it may with the Tak prism.

I often leave the Tak setup for Solar white light, but the Vixen won’t reach focus with my Baader CoolWedge, so knowing I’m not missing anything with the Vixen I can keep the Tak for Solar during the summer and use the Vixen for Astro.

So, a rather dull, but still interesting score draw I think.

Please forgive the old loo seat in the pictures.... being kept for firewood at some stage!! 🤪🤪

 

[Geoff Barnes]

You're spoiled rotten Stu! 😂

[Joe G]

Hi Stu

Best looking FL102S I’ve seen to date. The updated black focuser is a great match to the original. Enjoy 

Joe

[Stu]

48 minutes ago, Joe G said:

Hi Stu

Best looking FL102S I’ve seen to date. The updated black focuser is a great match to the original. Enjoy 

Joe

Thanks Joe. Yes, it is rather lovely. The focuser is much better than the original, although that was quite a nice example which I will keep hold of. I should try the original 0.965” Vixen Orthos out in it too now that I’ve got an adaptor for them.

Another pic of it here, alongside the Genesis.

[Rob]

Lovely scopes you have there Stu. I'm sure they are an absolute pleasure to use. Enjoy!

Best Rob

[Guest]

I so want a refractor now!

[Stu]

1 minute ago, merlin100 said:

I so want a refractor now!

Sorry 😉🤪

[John]

Great report Stu

I wonder how they would compare on DSO's ?

Would the more up to date coatings and glass of the Tak claw back the 2mm aperture gap ?

Find out in next months exciting installment !

[Stu]

3 minutes ago, John said:

Great report Stu

I wonder how they would compare on DSO's ?

Would the more up to date coatings and glass of the Tak claw back the 2mm aperture gap ?

Find out in next months exciting installment !

Will certainly give that a go John. Couldn’t stay up late last nice so I didn’t try M13 or M57 which would be among the better targets from here. You will have to wait with bated breath 🤣🤣

[mikeDnight]

You've definitely got a 4" fetish thing going on deep inside Stu. They are all beautiful though!  Decision making isn't my strong point, so I don't know how I'd cope having to choose between them. It did cross my mind just how lovely theye'd look if you had them in an observatory in your little corner there! 

[JeremyS]

Really interesting and well executed report, @Stu. I've been looking forward to it for a while and wasn't disappointed - and neither were you by the sounds of it 🙂

 

[Alan White]

Interesting comparison.
The picture look to show 3 scopes though, have I missed something?
Nice 3 scopes if they are, all classic and Japan made kit.

As others have said, you are a lucky chap to have them.

 

[Stu]

42 minutes ago, JeremyS said:

Really interesting and well executed report, @Stu. I've been looking forward to it for a while and wasn't disappointed - and neither were you by the sounds of it 🙂

 

Thanks Jeremy. More to come I’m sure, but I confess I was surprised. I thought the Tak would win by a head.

[Stu]

38 minutes ago, Alan White said:

Interesting comparison.
The picture look to show 3 scopes though, have I missed something?
Nice 3 scopes if they are, all classic and Japan made kit.

As others have said, you are a lucky chap to have them.

 

There are actually four Alan 😱😱

Televue Genesis f5

Tak FC100DC f7.4

Vixen FL102S f9

Vixen 102mm f10 PST mod

One US imposter in there, and I won’t mention the Russian TAL 100r lurking somewhere around 🤣🤣. I really should take the ERF out of the Vixen f10 and see how it fares at night.

[Alan White]

Now @Stu, four or is it 5 or more and growing? 
They clearly are not enough, any astronomer can see this.

It must be you having those four eyes after all,
do you have a row at the back as well that you don't mention 😉

[Stu]

36 minutes ago, Alan White said:

Now @Stu, four or is it 5 or more and growing? 
They clearly are not enough, any astronomer can see this.

It must be you having those four eyes after all,
do you have a row at the back as well that you don't mention 😉

Five is plenty I think Alan, although I keep being tempted to add a 102mm f11 as a final one to compare.

I’m having a little 4” moment currently, although I do think I’ll keep them all apart from the TAL.

[Alan White]

Just a wafffer thin Mint Mr Creosote?  or Mr Stu 🤣

[jock1958]

Thanks @Stu very interesting that the Tak & Vixen are so evenly matched and looking forward to further episodes of this clash of titans!

Also got to compliment you on your spectacular array of equipment I’m not jealous honest!! 
 

I picked up on your comment in regards to the speed of operation of the slo mo controls, is it geared up in comparison to say the Skytee 2? and did you get those slo mo cables with the AZ100? I’m after a couple of fairly long ultra floppy cables. 

[Stu]

7 minutes ago, jock1958 said:

Thanks @Stu very interesting that the Tak & Vixen are so evenly matched and looking forward to further episodes of this clash of titans!

Also got to compliment you on your spectacular array of equipment I’m not jealous honest!! 
 

I picked up on your comment in regards to the speed of operation of the slo mo controls, is it geared up in comparison to say the Skytee 2? and did you get those slo mo cables with the AZ100? I’m after a couple of fairly long ultra floppy cables. 

Thanks Jock. Yes, I was pleasantly surprised myself. It’s always possible that more subtle differences would show themselves at higher power on doubles for instance, although I split Zeta Herc with the Vixen recently so can’t be too shabby.

What I actually meant with the Slo Mo controls was that compared with using the DD3 and MT1 motors on my Vixen GP it is much quicker and more intuitive. I suspect the gearing is similar to the SkyTee 2 but I’ve not used one so can’t comment. The cables are the ones supplied with the AZ100 and are very good, long and just the right flexibility.

[Highburymark]

What a fine and beautiful telescope the Vixen is - at this level any differences must be paper thin if you can’t divide them Stu. it’s the weight and ergonomics that would push me towards the Tak, but the FL102 is easier on the eye in my view. Stunning!

[Stu]

21 hours ago, mikeDnight said:

You've definitely got a 4" fetish thing going on deep inside Stu. They are all beautiful though!  Decision making isn't my strong point, so I don't know how I'd cope having to choose between them. It did cross my mind just how lovely theye'd look if you had them in an observatory in your little corner there! 

Indeed I have Mike!

It wasn’t really my intention to do this, but the Genesis joined me for the widefield views it gives, and then I couldn’t resist the FL102S to see just how good they are. The TAL then became part of a project to compare different 4” scopes to give me a focus for my astronomy as conditions aren’t good for DSOs round here. The PST mod almost doesn’t count does it? 🤣

Decision making is simplified by the fact that the Genesis is normally just used for widefield if I get to a dark site, and I’m tending to use the Tak for solar a lot these days, and would be one that comes away with me if I travel. The Vixen is a home scope for lunar, planetary and doubles. The joy of the AZ100 is that I can use two at once! Genesis and Vixen making most sense side by side for the different views.

[Alan White]

Interesting that the Tak is being sidelined by the Vixen FL.

[Stu]

37 minutes ago, Alan White said:

Interesting that the Tak is being sidelined by the Vixen FL.

Well, I probably have still been using the Tak more when solar observing, and also lunar but yes, now I know I’m not missing out on much of anything I will enjoy the Vixen as much as possible.

[mikeDnight]

The Vixen FL102 was the scope that sent me hurtling down the steep and expensive apo slope. In my not so humble opinion, it is as good as anything else out there, at least as far as visual is concerned. If I'd have been able to get my hands on a new one back in 2003, im convinced I'd still be using it today. OO, the sole Vixen importer back then, faild me dramatically, and so i had only two directions in which to turn - TMB or Takahashi. Although TMB looked great, I had no experience of them and they were triplets that didn't use fluorite. The Vixen used fluorite and I wanted fluorite, so Tak was the only option, and so began my love affair with Takahashi. My first true love though was the Vixen. 💘

[John]

Back in 2016, when I was on the hunt for a top end refractor, I would have happily gone for a nice Vixen FL102. It would have made a grrat companion to my Vixen ED102SS. None came up during my "window of patience" though so I went for the Tak FC100-DL instead. With the objectives of the same spec (all bar 2mm of aperture) and from the same optical company I would imagine that the 100DL and the FL102 would produce very, very similar performance. Maybe I'll get a chance to find out someday