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Are binoviewers just as great on DSO's?

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#1 NorthWolf

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Posted 10 August 2014 - 09:59 PM

Now that I've looked through and gotten addicted to binoviewers for solar, lunar and planetary, as well as open clusters, if I go to a dark site, or even in my light polluted zone, will I find there are certain advantages on dso's with the binoviewers? Do you still get the space walk feeling?



#2 Eddgie

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Posted 10 August 2014 - 10:19 PM

Impressions vary.

 

Binoviewers will dim most DSOs very slightly, but not so much as to make them much harder to see.

 

For extended objects like nebula, the trick is to use slightly less power when binoviewing than you would use in mono-view.

 

For stellar DSOs like Globular Clusters, you will loose some resolution.

 

Even with these, I still feel that objects have more presence when viewed with binoviewers.   It did not happen all at once though, the way it does with the moon or planets.    It took some time.  At first, I just felt things looked a bit to dim, but again, once I lowered the magnification slightly, and learned to just relax and enjoy the view, I found that for me personally, DSOs started to look better in binoviewers.     

 

I remember last winter, cruising though the winter Milky Way with my SV110ED, Mark V binoviewers, and 24mm ES eyepeices.    The two degree field did not seem as bright as it was in a 4" APO using monovision, but I enjoyed it so much more!    It felt so natural and immersive!

 

I still ocassionally use a single mono-view eyepiece in my dob, but every time I do, I am eager to take it out and put the Binotron back in.  I just enjoy it more that way.



#3 NorthWolf

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Posted 10 August 2014 - 11:19 PM

Impressions vary.

 

Binoviewers will dim most DSOs very slightly, but not so much as to make them much harder to see.

 

For extended objects like nebula, the trick is to use slightly less power when binoviewing than you would use in mono-view.

 

For stellar DSOs like Globular Clusters, you will loose some resolution.

 

Even with these, I still feel that objects have more presence when viewed with binoviewers.   It did not happen all at once though, the way it does with the moon or planets.    It took some time.  At first, I just felt things looked a bit to dim, but again, once I lowered the magnification slightly, and learned to just relax and enjoy the view, I found that for me personally, DSOs started to look better in binoviewers.     

 

I remember last winter, cruising though the winter Milky Way with my SV110ED, Mark V binoviewers, and 24mm ES eyepeices.    The two degree field did not seem as bright as it was in a 4" APO using monovision, but I enjoyed it so much more!    It felt so natural and immersive!

 

I still ocassionally use a single mono-view eyepiece in my dob, but every time I do, I am eager to take it out and put the Binotron back in.  I just enjoy it more that way.

You've completely made me into a binoviewer convert! It will never be the same. All my plans have changed, time to go back and plan.



#4 Jawaid I. Abbasi

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Posted 10 August 2014 - 11:32 PM

From my own experience; DSO will be Dim and resolution will definately low in Binoviewer. For DSO; I will recommand a 100mm Binocular especially for dark site. I took both the Oberweck 25x100D and my binoviewer and I can certainly say that the Binocular showed me well.

 

I used binoviewer with the telescope all the time and it is very confortable to use it just like Binocular but the binocular showed me well as I said it above.



#5 Astrojensen

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Posted 11 August 2014 - 03:16 AM

My experience with binoviewers on DSO is that the resolution is not harmed in any way, but you do lose about half a magnitude of light grasp. Contrast, however, is markedly improved, as is ergonomics. Eye strain is very much reduced. This means that details in galaxies is improved, in my experience, as long as the details are bright enough to be detected. You do lose the faintest stars in globulars, but they increase a LOT in "3D" feeling. 

 

The downside is that, due to the restriction in maximum field stop diameter, you lose a lot of potential true field, since you can't use 2" eyepieces. As a consequence, I tend to bounce a lot back and forth between binoviewers and wide-field eyepieces, when it comes to deep-sky observing. Lunar/planetary, double stars and solar observing is nearly 100% binoviewer territory. On these targets, I have *better* resolution with the binoviewer than with any high-end eyepiece.  

 

A key to enjoy binoviewing deep-sky objects is, in many cases, to use as low magnification as at all possible. On a lot of scopes, you really struggle to get it low enough. Particularly SCTs and long focus refractors. The important thing is the f/ratio. The faster, the better (almost!). My 72mm f/6 ED refractor can give some mighty impressive low-power binoviewer views. My 63mm Zeiss f/13.3 also works really well, but is much more limited in the range of objects it will show well. My C8 is fine on a lot of objects, as long as they fit in the small field of view. Globulars are amazing. My 12" f/5 gives superb views, but needs a 1.7x corrector, which will increase the effective f/ratio to f/8.5. Most Messiers are amazing in it. It is equivalent of having a true 8.5" binocular, but much less bulky.

 

My experience is that binoviewers work splendidly well for deep-sky observing, but has some caveats you need to be aware of, to make them work well. 

 

 

Clear skies!

Thomas, Denmark


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#6 Jeff B

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Posted 11 August 2014 - 08:18 AM

Now that I've looked through and gotten addicted to binoviewers for solar, lunar and planetary, as well as open clusters, if I go to a dark site, or even in my light polluted zone, will I find there are certain advantages on dso's with the binoviewers? Do you still get the space walk feeling?

 

Yes and yes.  Open clusters in particular.  It will take just a glance at the Wild Duck or double clusters with the bino-viewer to immediately convince you.  

 

Jeff 


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#7 LA_Stars

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Posted 11 August 2014 - 09:53 AM

Hello all- Good reading. I just picked up a Denk II BV (pre owned), and am looking forward to using it- The Denk did not come with a nose piece so I'm trying to track one down (1.25").

Should I consider a focal reducer as well? I will be doing both astro and terrestrial with my scope-  Meade LX80 SCT mounted on an ES Twilight II alt-az, regualr Meade SCT>1.25" VB adapter. Telrad and an orion 9x50 CI finder

 

For astro: Televue 90 1.25" star diagonal (the good one)

For terra:  WO CI 45 diagonal that is getting returned because it is plastic and did not have good light or resolution (total newbie mistake). So I'm still looking for a quality fully-CI diagonal. suggestions?

My current EPs: two Baader 8-24 zoom EPs, Meade 24mm EP.  I am still researching which EPs to buy for astro (planetary, DSO etc) that give a good view without breaking the bank (sicne i have to buy two of each!).  The Baader zooms are intended mostly for terra use (convenient zoom), but they do give a nice astro view albeit slightly darker than a regular EP.

 

I also have an ES 2x focal extender, it is sort of like the TV's super barlow. Not sure if I will need it though with the Denk BV's?

 

I'm new at this so all experienced input from SCT-BV owners is sincerely appreciated.



#8 NorthWolf

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Posted 11 August 2014 - 10:21 AM

"Should I consider a focal reducer as well?"

 

That is a good question, one I am asking myself too. I wonder if it's useful for binoviewing, on a SCT too.



#9 Doug Culbertson

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Posted 11 August 2014 - 10:34 AM

If you are talking about one of the typical f/6.3 corrector/reducers, you will not be able to focus a binoviewer with it in place in a SCT.

The Denkmeier Star Sweeper is the only reducer that I am aware of that will work with a binoviewer, but I don't know if the thread is compatible with any of the China sourced binoviewers; i.e. WO, Celestron, Arcturus, etc.


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#10 LA_Stars

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Posted 11 August 2014 - 11:35 AM

Just spoke w/ Russ @ Denkmeier. Really cool guy. He hooked me up with the correct 1.25" nose piece for the Denk II and also the correct focal reducer (1.7x). These are apparently proprietary threads that attach to the nose side of the Denk II. 

 

I explained my use of the Meade 6" SCT for both astro and terra viewing, and he strongly recommended using the focal reducer on terra viewing to help clean up the image across long distances. Anyway, sure can't complain a bit about his support and service. A+


Edited by LA_Stars, 11 August 2014 - 11:37 AM.


#11 GlennLeDrew

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Posted 12 August 2014 - 05:05 AM

A focal reducer "to clean up the image over long distances" for terrestral work. What an odd way of putting it. ;) All you're doing here is using a lower power so that atmospheric 'boiling' is reduced in scale.

 

Another reducer which is designed specifically for SCTs is the Alan Gee MkII. It has a generous working distance which is very bino viewer friendly.

 

As to the efficacy of BVs on DSOs, the principal fact is the diminution to 50% in each eye. But the visual system integrates these two images so as to realize a gain in signal to noise of 41%. This does partially redress the dimming, although a *slightly* larger exit pupil will be required in order to enjoy the same surface brightness as for the mono view. HOWEVER, as long as the target is not at the limit of detection, image size is often more important than sheer brightness. The light-starved eye requires sufficient object size for detection. Decreasing magnification in order to boost brightness may actually push details to below the threshold size for detection.


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#12 LA_Stars

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Posted 12 August 2014 - 08:19 AM

A focal reducer "to clean up the image over long distances" for terrestral work. What an odd way of putting it. ;) All you're doing here is using a lower power so that atmospheric 'boiling' is reduced in scale.

 

Another reducer which is designed specifically for SCTs is the Alan Gee MkII. It has a generous working distance which is very bino viewer friendly.

 

As to the efficacy of BVs on DSOs, the principal fact is the diminution to 50% in each eye. But the visual system integrates these two images so as to realize a gain in signal to noise of 41%. This does partially redress the dimming, although a *slightly* larger exit pupil will be required in order to enjoy the same surface brightness as for the mono view. HOWEVER, as long as the target is not at the limit of detection, image size is often more important than sheer brightness. The light-starved eye requires sufficient object size for detection. Decreasing magnification in order to boost brightness may actually push details to below the threshold size for detection.

 

Yep you stated it bit more precisely as how Russ described it re: turbulence and reducer. I'm not expecting magic here, good viewing is always going to be dependent on conditions. But if the reducer helps a bit I'll use it.  Thanks for your input on BV and DSO use-  Much appreciated.

 

Last piece I am trying to decide on is an erect image diagonal for terra viewing / daytime only. I had purchased a WO 1.25" 45 erect diagonal, and it was terrible in my setup. View was rather dark, focus not that great, plastic body not confidence inspiring to hold the BV.  I returned it.  So am looking for an amici-type prism 45 diagonal that has a decent effective aperture size, either 2" or 1.25", that can support the BV adequately. I realize the Baader 90 amici would be a good choice, but the 90 makes viewing angles difficult vs a 45.



#13 REC

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Posted 12 August 2014 - 08:49 AM

Just to add to the above comments, two items that really looked impressive in my BV as a DSO was M42 and the Double Star Cluster.....awesome sight!  For DSO's I use a lower power with a bigger exit pupil and a pair of 26mmSP.

 

Bob



#14 NorthWolf

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Posted 12 August 2014 - 10:15 AM

A focal reducer "to clean up the image over long distances" for terrestral work. What an odd way of putting it. ;) All you're doing here is using a lower power so that atmospheric 'boiling' is reduced in scale.

 

Another reducer which is designed specifically for SCTs is the Alan Gee MkII. It has a generous working distance which is very bino viewer friendly.

 

As to the efficacy of BVs on DSOs, the principal fact is the diminution to 50% in each eye. But the visual system integrates these two images so as to realize a gain in signal to noise of 41%. This does partially redress the dimming, although a *slightly* larger exit pupil will be required in order to enjoy the same surface brightness as for the mono view. HOWEVER, as long as the target is not at the limit of detection, image size is often more important than sheer brightness. The light-starved eye requires sufficient object size for detection. Decreasing magnification in order to boost brightness may actually push details to below the threshold size for detection.

Nicely said, well explained!! Glenn, based on what you wrote, can you recommend me 2 ep sets (1 high grade, and 1 inexpensive) for general DSO viewing with an F10 1500mm SCT (6SE) and 2 sets for an EdgeHD 8 F10 2032mm. 


Edited by NorthWolf, 12 August 2014 - 10:17 AM.


#15 rockethead26

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Posted 12 August 2014 - 12:30 PM

Also, take a look at M13 at med-high power in your binoviewer. Most impressive!



#16 GlennLeDrew

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Posted 12 August 2014 - 03:18 PM

I tend to retreat from making eyepiece recommendations. The variety of options is just too vast, and individual preference unpredictable. ;) Suffice it to say, for an f/10 scope one need not fret if eyepieces are not top grade. Any half decent ocular will do fine, even for more stringent tasks as planet observation. The limit imposed by the BV's generally smallish rear prism aperture precludes the largest field stops, and so basic Plossls in the 20mm and longer focal length range are fine. Wider angle designs are worthwhile in shorter focal lengths, but they need not be Deloi, Naglers or Ethoi.


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#17 Sorny

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Posted 12 August 2014 - 03:45 PM

 

A focal reducer "to clean up the image over long distances" for terrestral work. What an odd way of putting it. ;) All you're doing here is using a lower power so that atmospheric 'boiling' is reduced in scale.

 

Another reducer which is designed specifically for SCTs is the Alan Gee MkII. It has a generous working distance which is very bino viewer friendly.

 

As to the efficacy of BVs on DSOs, the principal fact is the diminution to 50% in each eye. But the visual system integrates these two images so as to realize a gain in signal to noise of 41%. This does partially redress the dimming, although a *slightly* larger exit pupil will be required in order to enjoy the same surface brightness as for the mono view. HOWEVER, as long as the target is not at the limit of detection, image size is often more important than sheer brightness. The light-starved eye requires sufficient object size for detection. Decreasing magnification in order to boost brightness may actually push details to below the threshold size for detection.

Nicely said, well explained!! Glenn, based on what you wrote, can you recommend me 2 ep sets (1 high grade, and 1 inexpensive) for general DSO viewing with an F10 1500mm SCT (6SE) and 2 sets for an EdgeHD 8 F10 2032mm. 

 

 

To keep it simple, by putting a binoviewer on your C6 or a C8, just figure on being closer to f/12 than f/10. It saves a lot of hassle in figuring out what eyepieces to get.

 

If you've got a small prism binoviewer, I'm a pretty big fan of Agena SWA 15 & 20mm pairs in a small scope/small prism combo. That's what I run with my WO bino in my C5. They're inexpensive, and very light. With the gentle light curve they get in a binoviewer in an SCT, they perform quite well indeed (as Glen said, most eyepieces perform well with slow scopes).

 

If you want to spend more money, then I'd recommend "comfortable" eyepieces. For me, that means ample eye relief. Think Delos, Radian, Vixen (LVW or NLV), Denk D14/D21, and Pentax XW. The LVW, Pentax, Denk & Delos can all be a bit "fat" so make sure they'll fit your face first. 


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#18 jgraham

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Posted 12 August 2014 - 05:18 PM

My brain knows the the image is fainter when I use my binoviewers, but my perception doesn't pick that up. For me, the complete removal of eye strain makes up for any loss in brightness. Observing deepsk objects with my binoviewers is a wonderful experience.



#19 LA_Stars

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Posted 12 August 2014 - 11:48 PM

 

 

A focal reducer "to clean up the image over long distances" for terrestral work. What an odd way of putting it. ;) All you're doing here is using a lower power so that atmospheric 'boiling' is reduced in scale.

 

Another reducer which is designed specifically for SCTs is the Alan Gee MkII. It has a generous working distance which is very bino viewer friendly.

 

As to the efficacy of BVs on DSOs, the principal fact is the diminution to 50% in each eye. But the visual system integrates these two images so as to realize a gain in signal to noise of 41%. This does partially redress the dimming, although a *slightly* larger exit pupil will be required in order to enjoy the same surface brightness as for the mono view. HOWEVER, as long as the target is not at the limit of detection, image size is often more important than sheer brightness. The light-starved eye requires sufficient object size for detection. Decreasing magnification in order to boost brightness may actually push details to below the threshold size for detection.

Nicely said, well explained!! Glenn, based on what you wrote, can you recommend me 2 ep sets (1 high grade, and 1 inexpensive) for general DSO viewing with an F10 1500mm SCT (6SE) and 2 sets for an EdgeHD 8 F10 2032mm. 

 

 

To keep it simple, by putting a binoviewer on your C6 or a C8, just figure on being closer to f/12 than f/10. It saves a lot of hassle in figuring out what eyepieces to get.

 

If you've got a small prism binoviewer, I'm a pretty big fan of Agena SWA 15 & 20mm pairs in a small scope/small prism combo. That's what I run with my WO bino in my C5. They're inexpensive, and very light. With the gentle light curve they get in a binoviewer in an SCT, they perform quite well indeed (as Glen said, most eyepieces perform well with slow scopes).

 

If you want to spend more money, then I'd recommend "comfortable" eyepieces. For me, that means ample eye relief. Think Delos, Radian, Vixen (LVW or NLV), Denk D14/D21, and Pentax XW. The LVW, Pentax, Denk & Delos can all be a bit "fat" so make sure they'll fit your face first. 

 

 

Thanks for the F/12 info, good to know as well as EP suggestions. I have just the pair of Baader 8-24 click zoom EPs right now (got them mostly for terra use), and am shopping EP pairs for astro. Also need to find a decent 45 prism CI diagonal for terra use that is sturdy and has good clear aperture.  

 

I received the Denk II 1.25" nose piece and Star Sweeper cell from Russ today. super nice. can't wait to try it all out.  Russ totally hooked me up so "five stars" rating to him for sure.

 

I am also having a special short SCT visual back adpater machined up that only adds 6mm of length to the light path, and will accept T2 direct thread onto a Baader / WO / other T2 threaded diagonal, or, insertion of 1.25" accessories by way of a T2 threaded reducer lock collar. The clear aperture of the adapter will be 39mm if using T2 thread. It will probably be comprised of 5 parts and will be positionable, lockable, and sturdy.  This all started out because I could not find a good, shorty SCT to 1.25" adapter, only a Baader 11mm shorty SCT to T2.  So I figured why not have one made up that does both :D


Edited by LA_Stars, 12 August 2014 - 11:51 PM.


#20 NorthWolf

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Posted 13 August 2014 - 04:33 AM

Do you know where can one made for my binoviewers? I tried an adapter made to attach WO's or other similar sized binos straight into the t2 prism but it was too small for my binoviewers. I would need something a few mm bigger. I wonder if it would make any difference though, I'm currently using a clicklock and I don't want to remove it to attach the adapter and than binoviewers because it's just too good!

#21 LA_Stars

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Posted 13 August 2014 - 08:53 AM

Do you know where can one made for my binoviewers? I tried an adapter made to attach WO's or other similar sized binos straight into the t2 prism but it was too small for my binoviewers. I would need something a few mm bigger. I wonder if it would make any difference though, I'm currently using a clicklock and I don't want to remove it to attach the adapter and than binoviewers because it's just too good!

Only two places I know of are preciseparts.com and rafcamera.com - but you'd need to know the barrel diameter, thread pitch and thread depth for the Arcturus BV's. Thinking, if you go thread to thread from BV to diagonal it probably won't shorten the light path that much. But you'd be able to shorten up the path quite a bit with a "shorty" SCT adapter to diagonal. I was not planning on threading the Denk BVs to my diagonals / just use the nosepiece and thumb screws or click lock.  

 

Which T2 prism you have?  I was looking at two Baader diagonals- the "Amici-2" which comes with 2" extensions and 1.25" adapter, and the Amici-DX1 which is body only. The "Amici-2" costs less. But, I cannot tell if they both use the same Amici prism and have same aperture or not.



#22 NorthWolf

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Posted 13 August 2014 - 12:14 PM

I have this prism: T2 Zeiss Jena 90° diagonal prism (2456095 #1B)

 

I tried an adapter (gold piece) and it was too small.

 

Attached File  20140805_202809_resized.jpg   430.83KB   3 downloads

 

20140805_202758_resized.jpg



#23 LA_Stars

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Posted 13 August 2014 - 01:16 PM

I have this prism: T2 Zeiss Jena 90° diagonal prism (2456095 #1B)

 

I tried an adapter (gold piece) and it was too small.

 

attachicon.gif20140805_202809_resized.jpg

 

 

Nice prism-  I need the Amici version though for correct left-right terrestrial viewing.   Did you try the Williams Optics BV <> Baader T2 adapter on ebay (made by rafcamera.com) -  I think the Arcturus has the same nose piece threading as the WO.  M26x0.75   http://www.ebay.com/...=item3a8f3b2d00



#24 LA_Stars

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Posted 13 August 2014 - 01:19 PM

Either way I would suggest emailing Rafael at rafcamera. nice guy and if anyone can figure it out he can.



#25 NorthWolf

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Posted 13 August 2014 - 03:09 PM

That is the one in the picture. The Arcturus binos seem to need a bigger adapter.






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