Binoviewer William Optics

[Rig3l]

BINOVIEWERS William Optics

Hello forum, here my impressions about this binoviewer, I tried it with my dobson skywatcher 10", hope it can be helpfull!

The package includes:

-1.25” Binoviewer

-2x William Optics 20 mm WA 66 deg. eyepieces

-Barlow nosepiece (1.6x) for easier focusing with most telescopes

I know that an OTA version exists too, if you don't need these eyepieces.

The weight – withouth eyepieces - is about 520g. I didn't notice any balance or stability problem on my dobson.

BINOVIEWER W.O. on DOBSON SW 10". A Focus problem

As I said, I tried the binoviewer with my dobson, but it reaches the focus just with a barlow 2x (I used a standard televue 2x) + the binoviewer barlow 1.6x (I did not try with the 2x barlow only). Anyway, the magnification/zoom is too much for deepsky.

As you can see in the following pic, the "arm" with the original skywatcher 2" to 1,25" adaptor is too long!

... anyway, it allows to reach focus with high magnification. On Moon and Saturn (I tested it on them the first night, from my roof), the result was really wonderful!

But I wanted to use it on DSO too. I had to resolve the "inside focus" problem first.

So, to reach the focus also with low zoom, I replaced the original adapter from 2"to 1,25" with the Baader Pushfix (with only 1 mm optical height), and the original economic focuser ring (with the screw fixing-system) with a better one: a geoptik ring that use an inside brassy ring. In this way, I reduced the optical lenght, so now I can reach focus using the 1,6x bino-barlow and withouth the televue 2x (Cost: 60 euro for the 2 pieces)

You can see the difference here:

The pushfix is "half used"; it's possibile, with a further change (but piercing the focuser and the geoptik ring, to insert the screw of the pushfix), to use it fully, shorting in this way the optical lenght a little bit more. However, I decided to keep the first adjustement, because I'm satisfied - for now - with this result.

Another option could be a GSO adaptor as this in the pic (5mm optical lenght), considering that the baader is not used at 100%

Maybe, using the pushfix fully (it means to use really the 1mm lenght), the focus could be reached with a less zoomed barlow (a 1.2x for ex.) I don't know if them exist and if they are compatible with the Bino W.O. Just wondering.

Who has a collapsible tube should be able to reach focus simply using the trusses lenght, by blocking the secondary mirror not at the full opening but a little less. This solution is also more economic!

Summing up, the binoviewer post focuser-adjustment can reach focus with:

- his 1,6x barlow

- a standard barlow 2x

- with a barlow 2x + his 1,6x barlow

AN OBSERVING TEST

The view through both eyes is fulfilling: the tridimensional-feel make the experience more involving, and with no doubt using both eyes is really comfortable!

Moon is fantastic, beyond description.. you can find a new reason to watch moon when you can't go for deepsky Saturn and Mars (even if it's small)seem as little balls suspended in midair. I'm waiting for Jupiter now..

In addition, I was able to observe the Venus Transit with it.. great!

A particular category of DSO is really beautiful in bino vision: globular clusters. I tested it on M13 and M4. The loss of brightness is balanced by the depth you feel looking at them. Tried also on a wonderful M57.

PRICE

It was a gift, but I think it can considered an "entry level" binoviewer. You have to resolve the focus problem if you own a telescope with an inside-focus (but I'm satisfied because I spent less than a focuser change). It has a good quality/price balance, considering the eyepieces bundle.

PRO

Comfortable because you use both eyes

The tridimensional feel is great!

Really good quality/price balance

CONTRO

You lose a little brightness

The "inside-focus" problem on some newton

You could become addicted to the bino vision!

(I hope my english translation is clear.. sorry for some errors)

Clear Skies!

[knobby]

Nice, thanks for the info, I had the same focus problems with my SW250 dob. Used a Baader clikloc instead of the sw adaptor which sorted it

[Hairycamel]

I have the same inward travel focus problems on my 110 Megrez 5.9 Doublet, but the views are so good in my C8 that it's worth persevering for a solution to the refrator issue.

[LMC]

Nice review. I've had these for so long I'd forgotten about them!

I too use a Baader click-lock and have no issues in either any of my scopes (f15 Mak, f7 refractor or f5 Newt).

The moon is my main bino object, and with 24 Pans or 16 Naglers, I can just about go blind observing it.

A great bit of kit at a reasonable price.

Thanks again,

LMC

[Stu]

What sort of diagonal do you use in the f7 refractor LMC? Am trying to achieve focus in mine but no luck yet. Bought the binoviewer to use in my mak, but would like to use in the frac too.

Nice review btw, many thanks to the op

Cheers

Stu

[Epicycle]

Thanks for the review, very useful.

I was wondering about these as the bino-experience sounds very appealing. I have a Megrez 72 and I would imagine there will be a similar focusing problem, does anyone know an efficient way to deal with it?

[Stu]

Have now managed to get mine working well with the Astrotech, was great on the moon tonight.

Will post elsewhere to save hijacking this one.

Stu

[Brian Nordstrom]

Hi Rig31 , thanks for the review .

I to have a set of WO bino viewers as well( got them 2nd hand for $200 aud ) and they are very good to use , if the scope will come to focus !!

You need about 100mm of 'in' focus to acheave focus without a barlow .

I use my Celestron Ultima 2x when using my Takahashi SKY90 and Zeiss 63mm Telementor , its not a problem in the 500mm f/l SKY90 but the Zeiss at 840mm is a little long and the magnification gets high really fast , nice views in both tho .

I my home built Istar/Saxon 127mm f/8 refractor ( I built it with a tube lenght to suit the bino viewers and single eyepieces ) and my Takahashi Mewlon 210 I dont need a barlow as these 2 come to focus naturally , and the views are awsome .

The moon and jupiter just jump out at me when using 2 eyes , awsome ! .

I already own a TV 40mm plossel and next year I will get a second one to use along with the 20mm WO eyepieces , that should tone the magnification down a bit .

But I am sold on using 2 eyes , its great .

Enjoy the photos .

Brian.