Binoviewer use question to aid scope choice

[Stu]

4 minutes ago, Rangefinder10 said:

Here are some pics

I tried different focus lengths but to no avail.

I will try the GPC route to see if That is my solution

many thanks for all the helpful suggestions

John

It would likely be worth trying a T2 prism or 1.25” mirror diagonal to reduce the light path. How far off focus is it when the focuser is wound all the way in?

[Space Hopper]

Hi.

If its any help the 3 Baader GPCs will 'buy you back' the following lightpath in mm's

1.25x gpc     20mm

1.7x gpc       35mm

2.6x gpc      65mm

 

I'm not sure how compatible they are with the William Optics bino though, or where you even put them ?

If you go down the Baader prism diagonal route, the 2.6 gpc screws into that (rather than the bino in the case of Baader binoviewers)

 

Another option would be to try a 2" Barlow and see if it focuses with that first.......?

 

[Rangefinder10]

Stu

nothing in focus at all in any position, completely blurred

John

[Rangefinder10]

I’ll put in a question to Williams in the USA to try and obtain more info

John

[Rangefinder10]

3 minutes ago, Space Hopper said:

Hi.

If its any help the 3 Baader GPCs will 'buy you back' the following lightpath in mm's

1.25x gpc     20mm

1.7x gpc       35mm

2.6x gpc      65mm

 

I'm not sure how compatible they are with the William Optics bino though, or where you even put them ?

If you go down the Baader prism diagonal route, the 2.6 gpc screws into that (rather than the bino in the case of Baader binoviewers)

 

Another option would be to try a 2" Barlow and see if it focuses with that first.......?

 

Thanks Rob

I think that Ihave  a 2” Barlow tucked away somewhere.

I’ll see if that works

cheers

John

[Rangefinder10]

Problem solved😀

And it was in my possession all of the time, but I hadn't thought to use it.

The little 1.6 W.O. barlow, sitting in my binoviewer box, screwed into the end of the bino!!

I'd tried various extension tubes but all obviously too long.

I had in mind that I needed much more focus draw than actually required.

Thanks to everyone for your help. The forum is a great source of knowledge and assistance.

cheers

John

[Space Hopper]

I should have realised the same, but didn't. Although i'm not that familiar with the WO bino.

But glad you got it sorted.

And please post your impressions with this setup : we'd love to hear them 🙂

 

 

[RobertI]

On 04/12/2020 at 19:16, Rangefinder10 said:

I have the W.O. Version ,  cost me £50, and at that price I thought “ nothing to lose”

Absolutely! Amazing price. I have the same binoviewer and have been enjoying some great views of Mars.

I'd be interested to know what magnification your barlow ends up giving you. I ended up using a 1.3x barlow which actually turned into a 5x barlow when used with the binoviewers (due to the increased barlow to eyepiece distance in the binoviewer I believe), giving me 175x in my 100ED refractor which was just perfect for Mars. 

[Rangefinder10]

On 06/12/2020 at 00:28, Space Hopper said:

I should have realised the same, but didn't. Although i'm not that familiar with the WO bino.

But glad you got it sorted.

And please post your impressions with this setup : we'd love to hear them 🙂

 

 

Will do, as soon as the clouds pass, whenever that will be!

[Rangefinder10]

On 06/12/2020 at 12:37, RobertI said:

Absolutely! Amazing price. I have the same binoviewer and have been enjoying some great views of Mars.

I'd be interested to know what magnification your barlow ends up giving you. I ended up using a 1.3x barlow which actually turned into a 5x barlow when used with the binoviewers (due to the increased barlow to eyepiece distance in the binoviewer I believe), giving me 175x in my 100ED refractor which was just perfect for Mars. 

Hi Rob

How do you do that calculation?

John

[RobertI]

1 hour ago, Rangefinder10 said:

Hi Rob

How do you do that calculation?

John

I believe the easiest way is to compare the view through the binoviewer with the view through the same eyepiece  without the binoviewer (the latter gives you a known magnification so you can work out the binoviewer magnification by comparing the view). You can either time how long a star takes to cross the field of view in both situations or you can look at a distant fence and count the panels. I chose the latter method! 😁 So in my case the 20mm eyepiece gives me a magnification of 35x and showed me 5 fence panels. The same eyepiece in the binoviewer showed me 1 fence panel, which indicates a magnification of 175x. I might try a more accurate measurement by timing how long a star takes to cross the field of view in each case and doing a similar calculation. 

Edited December 7, 2020 by RobertI