28 replies to this topic

[Kim2010]

From my limited experience so far with BVs, I find that the most convenient to use with them are SCTs and MCTs. No focus issues. Just plug and play so to speak.

 

With my 100ED, I find that I needed to use a Barlow to find focus, and I know this is an issue with the focuser, but due to the weight, the focuser creeps

 

I have yet to try the BV on my TS 125mm. But so far, so easy to use on the SCT and MCT.

 

In your experience, what do you think is your best scope for BV'ing?

[Astrojensen]

Refractors, hands down. Provided they are designed with enough back focus to accomodate the binoviewer. The reason? They can (usually) go to much lower magnifications than SCTs and MCTs, while still using relatively wide angle eyepieces. If I want to go to even medium power with my 150mm f/15 Mak, I need to use two 40mm 1.25" Plössls, with 40° AFOV. On my APM 152 I can reach 50x, using two 24mm ES68's. With the 40mm Plössls, I'm at just 30x. Also, the magnification doesn't automatically increase on a refractor, unlike on an SCT or MCT with moving mirror focuser.

 

Newtonians are more tricky. They can work, but it's more involved.

 

 

Clear skies!

Thomas, Denmark

[Kim2010]

I'll try them on my TS 125mm which has a better focuser than the 100ED. I'll try to find a fix to the "creeping" focuser of the 100ED when used with the heavy BV. Maybe I can just simply remove the EAF and reinstall/ re-screw the focuser locking screw and hope that can hold focus even with the heavy BV. Since I also use the 100ED for EAA, I was hoping I can keep the EAF installed and that the motor can prevent slippage when used with the BV, but apparently it can't. Oh well.

[Binofrac]

I only have an F11/102 refractor for binoviewing and it's very good for me. The magnification is sometimes higher than I'd like as I need  a barlow for focus but it is a great view.

[denis0007dl]

Refractors!
Period!

If not already bino friendly, I just cut tubus.

Denis

[Kim2010]

Do you need the GPC with a refractor though?

[Astrojensen]

Do you need the GPC with a refractor though?

Most of my refractors don't, because I use a Baader T2 setup and Zeiss binoviewer with relatively short light path (more or less like a Baader Maxbright, perhaps a little longer). 

 

Zeiss Telemator 63/840: Needs a 1.25x GPC with some eyepieces, depending on BW setup. 

 

WO 72/430mm: None needed.

 

Zeiss 85/1575mm: Idem. 

 

Altair Optics 102/1122mm ED: Idem.

 

APM 152/1200mm ED: Idem. 

 

 

Clear skies!

Thomas, Denmark

[Kim2010]

Most of my refractors don't, because I use a Baader T2 setup and Zeiss binoviewer with relatively short light path (more or less like a Baader Maxbright, perhaps a little longer). 

 

Zeiss Telemator 63/840: Needs a 1.25x GPC with some eyepieces, depending on BW setup. 

 

WO 72/430mm: None needed.

 

Zeiss 85/1575mm: Idem. 

 

Altair Optics 102/1122mm ED: Idem.

 

APM 152/1200mm ED: Idem. 

 

 

Clear skies!

Thomas, Denmark

 

 

How about correcting for the aberrations introduced by the BV? I read that GPCs are mainly for correcting those, and that the magnification and lengthening of focus are side-effects only. Do you really need a GPC or are the aberrations introduced in a refractor by a BV not that much anyway?

[PETER DREW]

For me, definitely a SCT, the bigger the better.  My 16" gives awesome BV views of the Moon and planets.

[MikeTahtib]

No good for dobs?  I have a linear binoviewer to use with my 16" f4.5.  i've only used it a couple times.  I would think the brightness of a dob would be beneficial when gutting the light to the eyepieces in half.

[cst4]

I really only break out my binoviewers on the moon and planets.  I kind of like them on bright doubles too.  Since I only really use them at high power, I prefer binos in my SCT's and MCT's which are larger and can go deeper than my refractors and have brightness to spare.  Plus, as you say, they are just plug and play in these designs.  I've had some great views with my binos in my refractors as well but just don't get them out as much with those scopes.  I use my fracs more for low power wide field viewing, in which case I prefer the brighter views of monoviewing.  I wouldn't mind a binoscope for low powers though... 

[havasman]

The only scope I binoview is the Ha solar scope (refractor) and it is great. I've just never been fond of the results with my other scopes. Denkmeier makes a dedicated nosepiece for Lunt Ha scopes with an optic in it and I always use that.

[vtornado]

Add a skywatcher collapsible dob to that list.  You just have to lower the upper cage a bit.

 

I have also read the linear bino viewers do not need so much infocus.  I haven't tried them.

Edited by vtornado, 27 March 2024 - 09:14 AM.

[Takuan]

It depends on the binoviewer. As already said, for deep sky, a linear with a dob is a solution that has nothing to envy of any other.

[RAKing]

I definitely prefer refractors, even if I have to use a 1.25x Corrector.  I have the magnifications worked out so I don't lose much of anything with this setup on my refractors.

 

I use a pair of 24 Panoptics and a set of T6 Naglers.  The views through the BV are very "Ethos-like". 

 

Ron

[betacygni]

I think the best scope is the scope you prefer in general, binoviewers doesn’t change the equation. They are basically fancy eyepieces in my mind and can be made to work in any scope.

I prefer refractors in general for other reasons, but a 2x amplifier should get you to focus with any scope, including reflectors. That will still provide a 3mm exit pupil which I find sufficient for nearly all deep sky objects.

[tturtle]

It seems to me that the SCT is almost tailor made for binoviewing. A very rigid non-moving attachment to the OTA, bigger aperture to overcome some light loss, and a big focus range. I enjoy my binoviewer on all my refractors and SCTs, but where it really wows is on the 9.25 SCT.

[Kutno]

Dobs.  Mike Tahtib, above, is right.  The light gathering issue is a great point he makes.  For me, it simply means just dropping a binoviewer into each of the Dobs I have and I'm ready to go.

[Eddgie]

I have used many types of telescopes with binoviewers and would say that there is no "best" scope. 

 

My best planetary views ever were with my 12" dob and a binoviewer.

 

My most rewarding planetary view was not of a planet, but rather of the moons Ganymede and Io through my C14. On a night of excellent seeing, I was able to see considerable detail on Ganymede and on another night, I had a magnificent view of Io, easily seeing the polar shading. 

 

As vtornado has mentioned, as much as I personally hated the Flextube 10" as a telescope due to the awful bearings and imbalance, it was actually an excellent binoviewer platform because even though the aperture was reduced slightly with a binoviewer, you still got one of the widest fields you can get using a larger aperture and it would be my top choice for large aperture wide field viewing with binoviewers.

 

My favorite scope for binoviewing is the 130mm binoviewer ready Apo but I don't use it for much other than viewing planets, the moon, larger clusters, doubles, and rich fields. The fact that I said it was my favorite for binoviewing doesn't mean I think it is the best scope for binoviewing because that would depend to  a very large degree on what you wished to do with it. I still use the binoviewer occasionally in my Costco dob for viewing small clusters and planetary nebula, but mostly I use the image intensfied eyepiece in the 10" these days.  

 

Just as there is no telescope that is best for all astronomy use, there is no telescope that is best for all binoviewer use. Most seasoned observers have more that on telescope, and most binoviewer users use their binoviewers in more than one telescope. The best telescope for binoviewing depends a great deal on what you want to observe. 

[noisejammer]

I pretty much only use my refractors for binoviewing. My TOA150 lets me observe from about 31x to ~300x which covers everything I'm interested in. My APM 115/805 spans 23x to ~230x. I seldom use them at the upper end of these ranges - 230x and 175x (respectively) are about where I draw the line.

 

How about correcting for the aberrations introduced by the BV? I read that GPCs are mainly for correcting those, and that the magnification and lengthening of focus are side-effects only. Do you really need a GPC or are the aberrations introduced in a refractor by a BV not that much anyway?

 

Bear in mind that spherochromatism from your binoviewers (and perhaps your diagonal) is/are dependent on the focal ratio of the scope. I find it's negligible at f/15 but obvious at f/7.

 

My experience at f/7 - a GPC is not necessary at low power - say up to 50x (perhaps 75x) because the aberrations created by the binoviewer are too small to be visible. Above that, spherochromatism starts to degrade the image.

 

The total chromatic aberration is also dependent on how much your scope creates itself. This means a triplet apo refractor should get away without a GPC at higher magnifications than an ED doublet will. It's complicated because some doublets are better corrected for colour than some triplets are. Experimentation should be your guide.

 

You may find that a Maksutov Cassegrain (typically f/12 to f/20) can operate without a GPC even though it will be at higher magnification. My f/9 12.5" RC needs a GPC most of the time but it's resolution is little better than my TOA so I seldom use it for eyeballing except when chasing something small and faint.

[Hubert57]

I use by WO bino mainly with my SCT (C6) - without GPC.

Otherwise I have tried them with a 2x barlow on an Obsession UC 18, with a Baader Neodymium filter, and it is a jaw dropping experience with good seeing.  

[Spikey131]

The best scope for binoviewing is the TV76 because it is so portable and I get tremendous wide fields with a pair of 24 Panoptics.

 

The best scope for binoviewing is the C8 because the moon and planets look amazing .

 

The best scope for binoviewing is the AP130GT because in comes to focus without a GPC and the wide field views of star clusters and bright nebulae are fantastic.  And with a 2.6x GPC the moon and planets are bright against a very black night sky.  During the day it is coupled with a Quark to show H-alpha details on the sun.

 

The best scope for binoviewing is the 16” Dob because of the details I can see on the planets surpasses all of my other scopes.

 

The best scope for binoviewing is the whatever you have

[ABQJeff]

So there you have it!  CN community once again provides a unified response.

 

There are only three scopes that are best for binoviewers: a Dob, a CAT or a refractor.  

 

In all seriousness it all depends on what your use case is.  I prefer Hi Mag planetary, lunar with BVs in my SCT(and use a GPC to correct for spherical aberration)  and prefer BVs when doing solar H-a with my Quark in my refractors.  If I want wide field two eye viewing, I use big binoculars.

[cptbobrfh]

I love my William Optics Binoviewer on my AT 102mm ED F/7 refractor, along with my Daystar Quark Chromosphere, for visual solar observing.

Bob

[jlinsobe]

I love my William Optics Binoviewer on my AT 102mm ED F/7 refractor, along with my Daystar Quark Chromosphere, for visual solar observing.

Bob

I want to get that one, the kit with two eyepieces.

I’m thinking of using a couple of Baader Mark IV zooms, or maybe celestron zooms.