Best Binoviewers? - Baader Mk5 v Tele Vue v Vernonscope

[25585]

The 3 binoviewers above seem to have lots of reviews. Tele Vue's design seems to have more inbuilt provision from what they say. 

Baader's Giant binocular viewer seems good for tall people using refractors and cassegrain designs.

Then there is Zeiss..

Which would you recommend as the most versatile to include f5 Newtonian use, or any other makes?

[alanjgreen]

I am using the Baader MarkV with the additional "Baader x1.7 newtonian glass path corrector" (which gives decent coma correction too) with my f3.6 20" dob and it works really well.

I cannot speak to the others you mention as these are the only binos i have owned.

I went for them due to the large prism allowing me to use panoptic 24 without light loss. The Baader T2 interchange system should not be underestimated, it makes connection to almost any scope possible and it allows you to keep the light path short.

I also love the quick release system for the eyepieces. And they are lightweight.

I also use them with my lunt60 for solar (requires the use of a Baader x1.7 gpc which just screws up inside the binos) and with my shortened tube borg89 for widefield (no gpc needed).

HTH,

Alan

[Louis D]

There's the Denkmeier Binotron 27 line as well.

[Louis D]

You might want to read Denis's review of a bunch of binoviewers on CN.

[Highburymark]

17 minutes ago, Louis D said:

You might want to read Denis's review of a bunch of binoviewers on CN.

What Denis doesn't know about binovs isn't worth knowing - was just reading his reports earlier. 

[25585]

Information  overload! ?

Maybe a WO to see if I use it, provided FLO stocks the latest, better bv.

So, to use mainly on my TV f5 500mm Genesis on the other end of a diagonal, would I need extra tubes etc? Probably only eps would be for min x30 magnification  - (what eye relief are the 20mm WO pair provided?)

[Louis D]

35 minutes ago, 25585 said:

Information  overload! ?

Maybe a WO to see if I use it, provided FLO stocks the latest, better bv.

So, to use mainly on my TV f5 500mm Genesis on the other end of a diagonal, would I need extra tubes etc? Probably only eps would be for min x30 magnification  - (what eye relief are the 20mm WO pair provided?)

It depends on how much in travel you have left.  I switched to a 1.25" diagonal to reach focus more easily with my AT72ED.  It increased my available focus distance by about 40mm IIRC.  Prism diagonals that directly attach via T2 fittings help even more.  Otherwise, you'll need some sort of OCS/GPC/barlow-nosepiece to reach focus.  I use the front of a Meade 140 2x barlow for this purpose in my Dob.

[John]

Usually binoviewers need around 100mm inwards focuser travel so it's not a case of needing extension tubes, rather the opposite. Using a barlow lens or glass path corrector can help reach focus if there is not enough inwards focuser travel available.

[niallk]

I had the privilege of looking through a TV BinoVue (on a Ha setup): I was very impressed!

My baseline for comparison is my own (much cheaper) Baader Maxbright BV, and TV plossls in both. The TV BV was exquisite to use.

[25585]

44 minutes ago, niallk said:

I had the privilege of looking through a TV BinoVue (on a Ha setup): I was very impressed!

My baseline for comparison is my own (much cheaper) Baader Maxbright BV, and TV plossls in both. The TV BV was exquisite to use.

[25585]

Tele Vue include all provisions for short and long fl scopes, selling a system. As they make short fl fracs, it may be the best as a package for my Genesis, and I can use their included tube for the C8.

[John]

I believe the TV binoviewer is a very good performer but I've read quite a few reports that they get out of collimation rather easily in transit ?

[YKSE]

7 hours ago, John said:

Usually binoviewers need around 100mm inwards focuser travel so it's not a case of needing extension tubes, rather the opposite. Using a barlow lens or glass path corrector can help reach focus if there is not enough inwards focuser travel available.

Exactly, and even more inward focusse travel for binoviewers with larger prism (Baader Mark V and Televue's BinoVue), something like 139mm for BinoVue e.g. Most refractors just don't have more than 100mm focus travel, so using binoviewer in native mode (=without a barlow or GPC) for wide-field of view is out of question.

[alanjgreen]

1. Your C8 will have no trouble focusing without any extra Barlow or extensions. There is plenty of focus range on an SCT so you know that any bino will work in your SCT  

- you will notice a x1.3 magnification increase though due to the amount you have moved the primary mirror during initial focusing

- expect to use several turns of the focuser knob to reach focus. But you WILL reach focus.

- this was my experience when I owned a C11

2. If a genesis is a refractor ? then you will need a glass path corrector (gpc) or Barlow to achieve focus, it cannot be avoided   (unless you buy a Borg)

if you already own a Barlow then use this with the binoviewer to help calculate the correct gpc that you need. Most manufactures make multiple gpc of different magnification and you need to buy the right one for your scope. Playing around with a cheap Barlow will help find the right one!

Here are 2 pluses for the baader t2 system

- you can attach the markV direct to a 1.25" baader prism diagonal to get the shortest possible light path length.

- you can attach the markV direct to a Lunt blocking filter for solar observing with binos

2a. Stay away from 2" diagonals, they eat too much light path. Stick with 1.25" if possible. I use a 1.25" zeiss prism diagonal and it is fantastic. Expensive yes, but brilliant !

3. You really don't want to use more than x1.6 or x1.7 gpc as then you lose the ability to use low power and see widefield  I think this is one of the reasons people focus on planetary where more magnification is used. Personally I love my binos and want to use them on as many objects as possible so keeping the light path short and using the smallest Barlow is vital.

- if you search the internet for genesis and binoviewer then you may find other users stating how they reached focus to get you started...

4. I bought a Borg refractor specifically because I can use it with binos and no gpc needed  (no unwanted extra magnification). Borg scopes are modular ( they are delivered in many little boxes that you then put together with no instructions - this was the only downside). I originally purchased the shortest 150mm tube but found the light path with markV and 1.25" zeiss prism shorter than expected. So, I simply purchased a extra 50mm tube that screws onto the 150mm tube so I now have a 200mm tube making up the body of my scope   If you go binos then the Borg modular system is terrific and versatile. Something you may want to consider in the future.

5. For your dob, you will likely need a x2 Barlow to get focus. I get focus with a x1.7 newtonian gpc in my dob but I have shortened trusses to help with this. I also use a focuser that has 2.5" of in-travel rather than the usual standard shorter travel range that you see on the stock focusers, this gives me more flexibility to reach focus. Expect to have to play around with multiple Barlows to find focus.

6. Most barlow lenses can be unscrewed from the Barlow body that they come in. If you use the Barlow lens without the body then you reduce the magnification multiplier. So, a standard x2 Barlow without the body may give x1.6. The body of the Barlow is there to keep a set distance separation from the Barlow lens to your eye. Changing this distance will change the actual magnification effects too.

Alan

[25585]

Thanks, I am looking at focusers and will probably get a Moonlite CR1. Would 60mm or 70mm focuser best to take any standard bino viewer?

[Louis D]

3 hours ago, 25585 said:

Thanks, I am looking at focusers and will probably get a Moonlite CR1. Would 60mm or 70mm focuser best to take any standard bino viewer?

On one of your Dobs?  It depends on where the image comes to focus.  To make a typical 23mm clear aperture binoviewer come to focus, the image plane needs to be at least 4 inches above the top of the racked in focuser.  Some folks make a second set of truss tubes that are 4" or so shorter than their regular set to allow native focus with their binoviewers.  Otherwise, you'll need an optical aid to throw the focal plane further back to enable focus through a binoviewer.