Binoviewers vs Cyclops

[Andrew_B]

13 hours ago, bond19 said:

Hi Malcolm.

I too am considering changing my 2" diagonal to achieve focus. Can I just clarify is the Badder diagonal you use a 1 1/4"?

I don't know if you've seen this article by William Paulini (BillP) reviewing different diagonals. There's some very useful info about optical path lengths which could be handy in deciding which diagonal to use and it shows prisms having significantly shorter optical lengths than equivalent mirrors as well as a useful comparison of other specifications and features.

[bond19]

On 17/10/2021 at 13:40, jock1958 said:

I have a Tak FC-100DL and WO BV's.

For me to achieve (native) focus without a Barlow / TV 2.5 Powermate or supplied WO 1.6x nosepiece I use a Baader 1.25 PRISM diagonal and a Baader ultra short clamp.

To achieve focus and increase magnification I use either a Barlow / Powermate or WO nosepiece and a 2" Baader MIRROR diagonal.

What I've found through trial & error and good SGL advice is a mirror diagonal uses up quite a lot of back focus compared to a prism diagonal, also switching to shorter adapters for native viewing did the trick for me.

Not sure how you could achieve this with your TV 102 & Dob but just a thought 🤔

 

On 17/10/2021 at 14:35, MalcolmM said:

Hi, I use a Baader T-2 Prism Star-Diagonal 32mm with a Baader Nosepiece 1.25" - T2 and Baader T-thread to 1.25" Helical Focuser. The helical focuser is a bit of a faff as unless you loosen the Binoviewers, they spin with the focuser! All bought through FLO. Hope this helps!

Thanks chaps. I’ll speak to the team at FLO and mention your suggestions and see if I can get this to work . I’d love to be able to view natively with the Binoviewer. I can only imagine how the many star clusters will look. 

Edited October 18, 2021 by bond19

[MalcolmM]

26 minutes ago, bond19 said:

 

Thanks chaps. I’ll speak to the team at FLO and mention your suggestions and see if I can get this to work . I’d love to be able to view natively with the Binoviewer. I can only imagine how the many star clusters will look. 

Not sure what you mean by 'natively'. I should have mentioned I also need to use the x1.6 WO nosepiece (comes with the Binoviewers) attached to the scope side of the diagonal in order to achieve focus. It's all to do with how much in focus your scope has and how much extra light path the Binoviewers add. A chat with FLO would definitely be a good idea and prevent a bit of trial and error!

[Louis D]

Entry level binoviewers with ~22mm clear aperture have around a 100mm to 110mm optical path length.  Simply measure how far out your focuser is relative to its most retracted position with an eyepiece you would use in a BV focused at infinity in a 1.25" diagonal you already have.  Subtract that distance from 110mm if it is smaller.  The result is how much distance you need to remove from your current optical path to reach focus natively with the BV.  If you are already racked out more than 110mm at infinity, you should be in good shape to use a BV natively.  My APO refractor has a removable tube section ahead of the focuser to aid in reaching native focus with BVs.  It's one of the reasons I chose it over other options.

[F15Rules]

I posted a thread some time back showing how I could get my Tak FS128 to focus, using Baader Maxbright binoviewers (much the same optically as WO and other popular entry level brands) without using a barlow..

Although my thread was based on a T2 connectivity system and Baader Maxbright binoviewer, I'm currently using a Seben (same as Revelation) model which doesn't have a T2 connection at the nosepiece end - just a normal 1.25" fixed nosepiece.

I can still get native focus with no barlow, but with less room left to rack in the focuser further. I can say, though, that this setup does focus perfectly with a pair of Kson 16.8mm orthos with no barlow in my FS128.

Hope that's of some help..you can find my original thread here:

 

Edited October 19, 2021 by F15Rules
Typo

[jock1958]

Nice one Dave @F15Rules you beat me to it, I was just about to post photos of what I did to reach focus with & without barlows but your thread is much more detailed and in essence what I based my early bino viewing experiences on! 

There is a SGL thread specifically about the WO BV’s I’ll see if I can find it 🤔

 

Edited October 19, 2021 by jock1958

[jock1958]

 

Found that Williams Optics binoviewer thread from 2016, there's some good stuff in there and some nice diagrams explaining the different light paths of the prism & mirror diagonals 

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwigmePel9bzAhUPXMAKHR4FA40QFnoECBIQAQ&url=https%3A%2F%2Fstargazerslounge.com%2Ftopic%2F274841-williams-optics-binoviewer%2F&usg=AOvVaw33lXsRiLCMs2ASLv0X0wLv

Edited October 20, 2021 by jock1958

[jock1958]

13 hours ago, MalcolmM said:

Not sure what you mean by 'natively'. I should have mentioned I also need to use the x1.6 WO nosepiece (comes with the Binoviewers) attached to the scope side of the diagonal in order to achieve focus. It's all to do with how much in focus your scope has and how much extra light path the Binoviewers add. A chat with FLO would definitely be a good idea and prevent a bit of trial and error!

Hi Malcolm as you've probably guessed 'natively' is the ability of bringing your BV's into focus without the use of your WO nosepiece, barlows or glass path correctors (GPC's) 

As you say its about how much light path your BV's add and how to reduce this to reach focus natively. From what you've said you already have a prism diagonal (shorter light path than a mirror) so maybe swapping out your Tak 2" visual back for a Baader ultra short clamp like Dave @F15Rules and I did, it saved me 20mm of in focus with my Tak FC-100DL, there is another adapter that would save even more but they are out of stock.

Before rushing into spending more cash I would do more research as your FC-100DC is F 7.4 and mine is F9, so what works for me might not for you. 

Some photos below of my Tak with standard 2" visual back, 2" Baader mirror diagonal & WO BV's with 1.6x nosepiece. Baader ultra short clamp, 1.25" Baader prism diagonal, no nosepiece. Diagonals and ultra short clamp adapters. 

 

 

Edited October 19, 2021 by jock1958

[MalcolmM]

Hi @jock1958 and @F15Rules, thanks for your explanations and pictures. I believe I can remove part of the tube between the main tube and the focuser which will gain me a couple of inches of light path and allow me to reach native focus without the nosepiece.  In fact it might have been one of you that told me about this in another thread. I'm reluctant to do this at the moment as I currently get what I need. I assume the only benefit for me in achieving native focus would be lower magnification and wider FOV? Using a couple of Tak 28mm Erfles I can get a reasonably wide FOV. However if I want to go wider in the future you have given me the information I need

Malcolm

[bond19]

Binoviewing certainly presents its challenges. Thanks to everyone who has contributed. It’s been a steep but educational learning curve. 

[Space Hopper]

In my experience most 'imaging optimised' refractors should be able to binoview natively as they usually have a big focusing range to allow for 

cameras, filter wheels, OAGs etc.

And you know you have plenty of in-focus range when you can add a Herschel wedge into the train and STILL reach focus with no gpc etc.

[jock1958]

16 hours ago, MalcolmM said:

Hi @jock1958 and @F15Rules, thanks for your explanations and pictures. I believe I can remove part of the tube between the main tube and the focuser which will gain me a couple of inches of light path and allow me to reach native focus without the nosepiece.  In fact it might have been one of you that told me about this in another thread. I'm reluctant to do this at the moment as I currently get what I need. I assume the only benefit for me in achieving native focus would be lower magnification and wider FOV? Using a couple of Tak 28mm Erfles I can get a reasonably wide FOV. However if I want to go wider in the future you have given me the information I need

Malcolm

Hi Malcolm

Glad you’ve found a way of gaining a couple of inches of in focus, which tube are you looking at removing? 

Your right native will give you lower powered views with a wider FOV to a point, my WO BV’s have their limitations which include the reduction of light passing through them that’s why I tend to use them for high powered viewing of bright objects.
Another thing to consider is apparent vignetting on eyepieces greater than 25mm although I haven’t noticed this with my 26mm plossls,  let me know if you have this with your 28’s?
 

[MalcolmM]

2 hours ago, jock1958 said:

Hi Malcolm

Glad you’ve found a way of gaining a couple of inches of in focus, which tube are you looking at removing? 

Your right native will give you lower powered views with a wider FOV to a point, my WO BV’s have their limitations which include the reduction of light passing through them that’s why I tend to use them for high powered viewing of bright objects.
Another thing to consider is apparent vignetting on eyepieces greater than 25mm although I haven’t noticed this with my 26mm plossls,  let me know if you have this with your 28’s?
 

Hi, I have attached a pic. The bit ringed in red is the bit that can be removed apparently; I have not felt the need to try this yet - call me vain but I love the  look of the scope as is   I alternate between cyclops and bino mode and have a way of doing this which works for me. I have my WO Binoviewers permanently attached to a Baader prism and the 1.6x nosepiece is permanently attached to the prism on the scope side. So when I want to change from cyclops to Binoviewer mode, I just remove my Tak prism and eyepiece and plug in the Baader. I need the Baader as the Tak prism does not have the standard thread to take the nosepiece.

I must say I have not noticed any vignetting with the 28's but maybe if I look for it I'll see it  

I just did a wee check there in daylight and if by vignetting you mean a dimming of the image at the edge of the FOV then there was nothing obvious to me; that's not to say a more experienced observer would not notice it!

It was a bit of trial and error getting to this point, but for me anyway, that's all part of the fun of this hobby!

Malcolm

Edited October 20, 2021 by MalcolmM
Forgot to attach the pic!!!

[MalcolmM]

7 hours ago, Space Hopper said:

In my experience most 'imaging optimised' refractors should be able to binoview natively as they usually have a big focusing range to allow for 

cameras, filter wheels, OAGs etc.

And you know you have plenty of in-focus range when you can add a Herschel wedge into the train and STILL reach focus with no gpc etc.

I'm told the D in FC100DC stands for digital (i.e. imaging) but I have very little focus range. I suppose that's why Tak sell so many extenders etc. Dunno about you but ever since buying a solar filter I seem to just get wet from standing in the English rain

Malcolm

[Saganite]

Hi Malcolm,

One of the first things I did when I got my FC100DC was to remove the section shown ringed and the bino worked at native focus.  To revert to cyclops mode I simply plugged a 3" long extension into the focuser and then the diagonal.  This allowed very swift interchange.

[jock1958]

2 hours ago, MalcolmM said:

Hi, I have attached a pic. The bit ringed in red is the bit that can be removed apparently; I have not felt the need to try this yet - call me vain but I love the  look of the scope as is   I alternate between cyclops and bino mode and have a way of doing this which works for me. I have my WO Binoviewers permanently attached to a Baader prism and the 1.6x nosepiece is permanently attached to the prism on the scope side. So when I want to change from cyclops to Binoviewer mode, I just remove my Tak prism and eyepiece and plug in the Baader. I need the Baader as the Tak prism does not have the standard thread to take the nosepiece.

I must say I have not noticed any vignetting with the 28's but maybe if I look for it I'll see it  

I just did a wee check there in daylight and if by vignetting you mean a dimming of the image at the edge of the FOV then there was nothing obvious to me; that's not to say a more experienced observer would not notice it!

It was a bit of trial and error getting to this point, but for me anyway, that's all part of the fun of this hobby!

Malcolm

Ah that bit of tube, I don’t have that on my DL and as @Saganite says it’s an easy way to swap from one configuration to the other for DC owners.

As a matter of interest how do you attach your BV’s directly to your diagonal, do you need an adapter ring?

 

 

[MalcolmM]

4 minutes ago, jock1958 said:

Ah that bit of tube, I don’t have that on my DL and as @Saganite says it’s an easy way to swap from one configuration to the other for DC owners.

As a matter of interest how do you attach your BV’s directly to your diagonal, do you need an adapter ring?

 

 

I should have been more explicit! No, I have a T thread to 1.25" Helical focuser. And then the Binoviewer just slots in. I'll attach another pic which might make it more obvious, written English was never my strong point You can see the WO 1.6 nosepiece attached to the other end of the diagonal

Malcolm

[jock1958]

1 hour ago, MalcolmM said:

I should have been more explicit! No, I have a T thread to 1.25" Helical focuser. And then the Binoviewer just slots in. I'll attach another pic which might make it more obvious, written English was never my strong point You can see the WO 1.6 nosepiece attached to the other end of the diagonal

Malcolm

Ah that’s what I do more or less, I swapped out my helical focuser for the much better (IMO) Baader ClickLock and if I’m using the WO nosepiece I screw it into the end of BV. 
Recently I’ve been using a 2.5x TV power mate and 15mm TV plossls which gives me approx 150x. 
There is a way you can directly connect the WO BV to the 1.25 Baader prism diagonal but not sure how to do it? maybe sometime in the future I’ll invest in some Baader MB 2’s with the very connective T2 system 🤔

Pic below of latest configuration, it’s a bit tail heavy but I just rebalance to compensate. 

Edited October 20, 2021 by jock1958

[MalcolmM]

38 minutes ago, jock1958 said:

Ah that’s what I do more or less, I swapped out my helical focuser for the much better (IMO) Baader quick lock and if I’m using the WO nosepiece I screw it into the end of BV. 
Recently I’ve been using a 2.5x TV power mate and 15mm TV plossls which gives me approx 150x. 
There is a way you can directly connect the WO BV to the 1.25 Baader prism diagonal but not sure how to do it? maybe sometime in the future I’ll invest in some Baader MB 2’s with the very connective T2 system 🤔

Pic below of latest configuration, it’s a bit tail heavy but I just rebalance to compensate. 

Wow - that is some set up!

LOL we are going down the same path only you are ahead of me!

I find the helical focuser a pain and of limited use and was considering getting the click lock. I do like the Tak stock focuser though you need very deft movements to get focus sometimes - I see you have a 10:1 focuser?

I also have been admiring the Baader Max Brights but have seen some reviews suggesting that optically they do not provide much of a jump in views. So the verdict is still out on that one.

I have also considered the Power Mate but I have found I cannot use my Celestron barlows at all anywhere in the light path and I have them up for sale! I wonder would the Power Mate work in my configuration given it is optically different from a barlow? It would be yet another expensive suck it and see

Malcolm

 

[Franklin]

1 hour ago, jock1958 said:

There is a way you can directly connect the WO BV to the 1.25 Baader prism diagonal but not sure how to do it?

Adaptor made in Russia, available on Ebay. You would also need a T2 locking ring.

T2 female to M26x0.75 male thread adapter for binoviewer

 

[jock1958]

1 hour ago, MalcolmM said:

Wow - that is some set up!

LOL we are going down the same path only you are ahead of me!

I find the helical focuser a pain and of limited use and was considering getting the click lock. I do like the Tak stock focuser though you need very deft movements to get focus sometimes - I see you have a 10:1 focuser?

I also have been admiring the Baader Max Brights but have seen some reviews suggesting that optically they do not provide much of a jump in views. So the verdict is still out on that one.

I have also considered the Power Mate but I have found I cannot use my Celestron barlows at all anywhere in the light path and I have them up for sale! I wonder would the Power Mate work in my configuration given it is optically different from a barlow? It would be yet another expensive suck it and see

Malcolm

 

I already had a lot of the kit before I got into binoviewing also some of it is second hand.  

As you say the standard Tak focuser is good, however I eventually buckled and went for the very nice but expensive pinion feather touch, its brilliant end of!  If you don't want to spend on one of these there are cheaper options like the MEF3 and More Blue do nice ones, I have one fitted to my little Tak FS-60Q.

I already had my power mate and it works a treat, not sure if it would work for your setup though?  they do come up quite regularly on ABS for about £100 and if it doesn't work use it for cyclops or sell it on.

Cheers 

Edited October 20, 2021 by jock1958

[jock1958]

2 hours ago, Franklin said:

Adaptor made in Russia, available on Ebay. You would also need a T2 locking ring.

T2 female to M26x0.75 male thread adapter for binoviewer

 

Thanks for that I shall investigate this. Just had a look its £33 for adapter on eBay and £16 from RVO for T2 locking ring, might hang fire on that for just now 🤔

Edited October 20, 2021 by jock1958