Takahashi FC-100 and FC-76 advice

[John]

24 minutes ago, HollyHound said:

Ok, just popped out for 20mins to check this one thing...

Unfortunately, I can report that with the XW30 on my FC-76DCU, there is noticeable FC in about the outer 30% of the field. If I focussed on stars towards the edge and then moved those back to the centre, they would become blurry and vice versa.

I do also see astigmatism, but that’s because I have removed my Dioptrx to test on another eyepiece and have found my eyes have about 0.75 dioptre of astigmatism anyway.

When using the Panoptic 24, I see neither FC or astigmatism in this scope.

If I can find a way to get focus then I will try with my Tak Flattener, but given I’m already using a Baader T2 BBHS mirror diagonal, that might be tricky.

The only thing to bear in mind. Is that supposedly the XW40 has less FC than the XW30 🤔

Hope this helps.

Looking at the optical layout of the original and new / re-released 30mm and 40mm XW's, it does not look like anything has changed so I would expect the FC to be the same as well. Not as much as the 20mm and 14mm though:

Edited April 15, 2021 by John

[jetstream]

1 hour ago, HollyHound said:

Ok, just popped out for 20mins to check this one thing...

Thank you for this.

The XW's are excellent eyepieces regardless of the fc in some. I'm hoping to find a lightweight upgrade for the 42mm LVW, a good but not great eyepiece IMHO. I have a 16mm T5 and hopefully a 13mm Nagler soon, we'll see tomorrow. Round that off with the 3-6 Nagler zoom and the holes are in the higher fl's. The 32mm TV plossl is excellent in my TSA120 so not sure if I'll roust out a 24 Pan or not.

I would absolutely love to try the FC76 with a top 40mm eyepiece and filter on some of the huge nebs like the Meissa and up around the Elephants Trunk area. Not sure which Tak I'll get next but I sure appreciate the threads and info on them.

[Sunshine]

3 hours ago, paulastro said:

No need to be upset Jeremy.  You could just paint the whole scope white and then the handle will look fine 🙂.

I like the red Primaluce rings, I can spray paint my 102 red to match but, I'm afraid the strongman for Takahashi (Jeremy) will surely hire a hitman to take me out.

Edited April 15, 2021 by Sunshine

[HollyHound]

4 hours ago, jetstream said:

The XW's are excellent eyepieces regardless of the fc in some.

Absolutely, I use all of them regularly in my FC-76DCU, StellaMira 80mm f/10 and 6”CC. Despite some FC in the Tak, remember this is still a relatively short focal length refractor and they’re all very usable.

The XWs give superb, contrast, sharp views and they are the most comfortable eyepieces to view through and also don’t feel cold to the touch when swapping them.

I have the whole set, except for the XW40 (yet) and wouldn’t swap them... the XW14 is the weakest (for FC) but even then, I can and do swap between that and the Delos 14, simply because sometimes the XW does (just) show a little bit more the the centre... it might be subtle but it is there (for me).

The XW30 gives a huge expansive view and although the Ethos 21 gives the same FoV, there is no way I’m going to hang that successfully on the back of a small refractor on a lightweight mount, so it’s the best eyepiece for that job 👍

[JeremyS]

10 hours ago, mikeDnight said:

I think perhaps a little too much of a tough time. He's a really nice chap and loves his refractors, but I suspect SGL humour may not have been recieved as it was intended. 

Humour on SGL? I’m always deadly serious.

 

🤣

[HollyHound]

9 hours ago, HollyHound said:

When using the Panoptic 24, I see neither FC or astigmatism in this scope.

I should add that it’s not really my intention to use anything other than 1.25” eyepieces on the FC-76DCU in normal use, so the Panoptic 24 is a perfect wide angle eyepiece most of the time 👍

[Stu]

13 minutes ago, HollyHound said:

I should add that it’s not really my intention to use anything other than 1.25” eyepieces on the FC-76DCU in normal use, so the Panoptic 24 is a perfect wide angle eyepiece most of the time 👍

I love my 24mm Panoptic too, and wouldn’t be without it. I dislike the rectilinear distortion which makes the Moon an egg shape when off axis, but I guess it’s not really a lunar eyepiece!

[Commanderfish]

9 hours ago, jetstream said:

Thank you for this.

The XW's are excellent eyepieces regardless of the fc in some. I'm hoping to find a lightweight upgrade for the 42mm LVW, a good but not great eyepiece IMHO. I have a 16mm T5 and hopefully a 13mm Nagler soon, we'll see tomorrow. Round that off with the 3-6 Nagler zoom and the holes are in the higher fl's. The 32mm TV plossl is excellent in my TSA120 so not sure if I'll roust out a 24 Pan or not.

I would absolutely love to try the FC76 with a top 40mm eyepiece and filter on some of the huge nebs like the Meissa and up around the Elephants Trunk area. Not sure which Tak I'll get next but I sure appreciate the threads and info on them.

Apologies to offer an expensive solution but I was experimenting with the medium to short FL Ethos last night between gaps in the clouds.  The 6, 8, 10 and 13mm all balance pretty nicely and give lovely sharp views across the field.  The 17mm Ethos might be my new favourite in the FC-76, it's as wide a field as the Pan 24 but at x33 instead of the Pan's x24, so the background is darker.  To balance the 17mm the dovetail does need to be as far forward in the clamp as possible (flush with the back of the clamp), but it does balance without counterweighting.  The Ethos 21mm is too heavy to balance without counterweighting.  This was all with no second scope on the other side of the Mini Giro Ercole (second scopes usually dampen balance problems).

 

 

[Commanderfish]

8 hours ago, Sunshine said:

I like the red Primaluce rings, I can spray paint my 102 red to match but, I'm afraid the strongman for Takahashi (Jeremy) will surely hire a hitman to take me out.

You're damn right!  I may hate Tak green but the whole scope?  Some things are just sacrilegious.

 

[jetstream]

2 hours ago, Commanderfish said:

The 17mm Ethos might be my new favourite in the FC-76, i

Nice eyepieces!

I also have the 17E and it is superb, Congrats for having such nice glass!

[Sunshine]

3 hours ago, Commanderfish said:

You're damn right!  I may hate Tak green but the whole scope?  Some things are just sacrilegious.

 

Lol I would never do such a thing.

[jetstream]

9 hours ago, HollyHound said:

The XWs give superb, contrast, sharp views

What I'm looking for in the 40mm is contrast and high transmission with and without filters. Other things I can overlook if these 2 requirements are met, not that the 30mm and 40mm will be comprises anyway IMHO. After using Ethos/Delos class eyepieces in fast dobs on large extended objects I realized that the long fl EPs available and applicable to f7ish fracs is the weak link. 

Btw, I ordered a lunar camera today and tried for a 13mm Nagler but no stock, and so I wait.

[Arneb]

5 hours ago, Commanderfish said:

Apologies to offer an expensive solution but I was experimenting with the medium to short FL Ethos last night between gaps in the clouds.  The 6, 8, 10 and 13mm all balance pretty nicely and give lovely sharp views across the field.  The 17mm Ethos might be my new favourite in the FC-76, it's as wide a field as the Pan 24 but at x33 instead of the Pan's x24, so the background is darker.  To balance the 17mm the dovetail does need to be as far forward in the clamp as possible (flush with the back of the clamp), but it does balance without counterweighting.  The Ethos 21mm is too heavy to balance without counterweighting.  This was all with no second scope on the other side of the Mini Giro Ercole (second scopes usually dampen balance problems).

 

 

Very useful and timely information this as my 76DCU should arrive tomorrow.🙂

Sadly it does suggest I'll be unable to use my ES92 17mm with the scope without a counterweight though as it weighs more than the 21mm Ethos. Still I bought the scope for travel and I don't plan to be taking the ES92s with me on my trips.

It may be time to decloak my 34mm and 40mm Maxvisions though...

[John]

5 minutes ago, Arneb said:

Very useful and timely information this as my 76DCU should arrive tomorrow.🙂

Sadly it does suggest I'll be unable to use my ES92 17mm with the scope without a counterweight though as it weighs more than the 21mm Ethos. Still I bought the scope for travel and I don't plan to be taking the ES92s with me on my trips.

It may be time to decloak my 34mm and 40mm Maxvisions though...

I have the ES 92 17mm but with my refractors I tend to use the Delos 17.3mm much more often with the 24mm Panoptic for a lower magnification and wider true field.

 

Edited April 15, 2021 by John

[Cleetus]

23 hours ago, John said:

You can fit one of the Vixen handles onto the Tak clamp:

The colour difference might upset some though.

I wasn't upset at all today.....but now I've seen that picture I feel traumatised. 🤣🤣

[Cleetus]

13 hours ago, Sunshine said:

I like the red Primaluce rings, I can spray paint my 102 red to match but, I'm afraid the strongman for Takahashi (Jeremy) will surely hire a hitman to take me out.

Here you go. Note the Dec axis the wrong way around!!!

Edited April 15, 2021 by Cleetus

[Arneb]

4 minutes ago, John said:

I have the ES 92 17mm but with my refractors I tend to use the Delos 17.3mm much more often with the 24mm Panoptic for a lower magnification and wider true field.

 

I try to pretend the Delos range doesn't exist as the temptation is strong with those ones!😉 I love the ES92s but alas they are heavy beasts and those Delos would complement them nicely!

I've all the Maxvisions except the 24mm as I have the 24mm pan. So for lightweight travel with the 76DCU I'll likely go with the 24mm Pan, 16mm MV, 9mm Nagler and my Ultima barlow...

And then I'll doubt my decision and end up bringing so many additional eyepieces I'll end up paying excess baggage!

[HollyHound]

6 hours ago, Commanderfish said:

Apologies to offer an expensive solution but I was experimenting with the medium to short FL Ethos last night between gaps in the clouds.  The 6, 8, 10 and 13mm all balance pretty nicely and give lovely sharp views across the field.  The 17mm Ethos might be my new favourite in the FC-76, it's as wide a field as the Pan 24 but at x33 instead of the Pan's x24, so the background is darker.  To balance the 17mm the dovetail does need to be as far forward in the clamp as possible (flush with the back of the clamp), but it does balance without counterweighting.  The Ethos 21mm is too heavy to balance without counterweighting.  This was all with no second scope on the other side of the Mini Giro Ercole (second scopes usually dampen balance problems).

That’s is interesting and no apology necessary re expense, as I already have Ethos  6, 8, 13 and indeed 3.7SX and 21 too anyway. 

I hadn’t really considered trying these in the FC-76DCU, but now just might... although I suspect this will be mounted on the AZ100 rather than ScopeTech, due to the balance issues that may present themselves.

I’m still thinking really that I want to keep the this Tak setup as simple as possible though, but if the views are good 🤔👍

Just received another Baader 2” Clicklock for the FS-60CB today, so am thinking of trying the XW30 in that... no doubt it will be lots of FC, but the view will be super wide and may lead onto using the XW40 in this for “binocular” wide viewing. My Nikon 8x56 binoculars give 6.2 degrees, and the XW40 would give 7.8 degrees 😮

[Commanderfish]

5 hours ago, HollyHound said:

That’s is interesting and no apology necessary re expense, as I already have Ethos  6, 8, 13 and indeed 3.7SX and 21 too anyway. 

I hadn’t really considered trying these in the FC-76DCU, but now just might... although I suspect this will be mounted on the AZ100 rather than ScopeTech, due to the balance issues that may present themselves.

I’m still thinking really that I want to keep the this Tak setup as simple as possible though, but if the views are good 🤔

I see it as having two set ups; one travel set up based on 1.25' (scope balanced to the middle of the dovetail) and a home set up for 2" (scope balanced at the back of the dovetail).

Travel: Pan 24mm, Ethos 8mm, Nagler zoom 6-3mm

Home: Ethos 17mm (liking this more and more for the FC-76),  Ethos 10mm, Ethos 6mm, Ethos 4.7mm

Definitely try your 13mm

 

[Sunshine]

6 hours ago, Cleetus said:

Here you go. Note the Dec axis the wrong way around!!!

Now I'm all jealous about that beautiful mount and tripod!

[Commanderfish]

17 hours ago, jetstream said:

What I'm looking for in the 40mm is contrast and high transmission with and without filters. Other things I can overlook if these 2 requirements are met, not that the 30mm and 40mm will be comprises anyway IMHO. After using Ethos/Delos class eyepieces in fast dobs on large extended objects I realized that the long fl EPs available and applicable to f7ish fracs is the weak link. 

Btw, I ordered a lunar camera today and tried for a 13mm Nagler but no stock, and so I wait.

One nice widefield EP I've found that does balance with the FC-76 is the Panaview 38mm.  I haven't spent too much time with it and the FC-76, but it's sharp across the field to my eyes (although my eyes may not be as fussy as some).  It only weighs 500g.  It produces x15 and 4.7 degrees.

[HollyHound]

1 hour ago, Commanderfish said:

One nice widefield EP I've found that does balance with the FC-76 is the Panaview 38mm.  I haven't spent too much time with it and the FC-76, but it's sharp across the field to my eyes (although my eyes may not be as fussy as some).  It only weighs 500g.  It produces x15 and 4.7 degrees.

Good point, I did used to have a Panaview 38 and it was a decent eyepiece indeed 👍

[Commanderfish]

3 hours ago, HollyHound said:

Good point, I did used to have a Panaview 38 and it was a decent eyepiece indeed 👍

It's really very, very good at F7.5, as sharp across the field as EPs priced many times as much. I have considered buying the 32mm Panaview for this reason, but I can't see many reviews about, other than a general consensus that the 38mm is the best in the series.

[HollyHound]

26 minutes ago, Commanderfish said:

It's really very, very good at F7.5, as sharp across the field as EPs priced many times as much. I have considered buying the 32mm Panaview for this reason, but I can't see many reviews about, other than a general consensus that the 38mm is the best in the series.

I’ve had the Panaview 32 at the same time I had the 38 and it was pretty much the same as I recall.

It’s a lot lighter and doesn’t have that massive top that the 38 has. Funnily enough, I recall thinking at the time, how on earth anyone can use an eyepiece any larger, and yet here I am with an Ethos 21 🤣

I only really used it in f/10 or higher scopes, but do recall using it once in the ST120 (f/5) and seeing some FC, but that’s expected.

[jetstream]

@Commanderfish @HollyHound

If you guys were to compare the transmission and contrast on nebula how would the Panaview rate in relation to Ethos/Delos? Scatter?

My 42mm LVW falls short but is still Ok.