Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
Get a Cloudy Nights T-Shirt Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu uh, User

Equipment Discussions >> Binoviewers

Pages: 1 | 2 | 3 | (show all)
HowardK
Pooh-Bah
*****

Reged: 10/20/10

Re: Binoviewing Deep Sky new [Re: mark8888]
      #5845766 - 05/07/13 02:25 PM

Well.......

Its ugerly


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Binoviewing Deep Sky new [Re: HowardK]
      #5846372 - 05/07/13 07:02 PM

True enough... yet for SOME of us it might be an improvement?

Post Extras: Print Post   Remind Me!   Notify Moderator  
mark8888
Carpal Tunnel


Reged: 09/24/10

Re: Binoviewing Deep Sky new [Re: Mike B]
      #5846594 - 05/07/13 08:54 PM

I tell you it completely eliminates the problem of stray light, causing no fogging at all, at no weight or expense. And it's quite dashing, really.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pinbout
Postmaster
*****

Reged: 02/22/10

Loc: nj
Re: Binoviewing Deep Sky new [Re: mark8888]
      #5846614 - 05/07/13 09:02 PM Attachment (28 downloads)

I think the hooded vest should do something about the scary look...

Post Extras: Print Post   Remind Me!   Notify Moderator  
Kent10
scholastic sledgehammer
*****

Reged: 05/08/12

Re: Binoviewing Deep Sky new [Re: Pinbout]
      #5847403 - 05/08/13 09:41 AM

Here is more talk about fogging eyepieces.

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/1,2,3,4,5,8/Number/5521508/Main/5521042

You need to copy and paste the link.


Post Extras: Print Post   Remind Me!   Notify Moderator  
George N
Carpal Tunnel
*****

Reged: 05/19/06

Loc: Binghamton & Indian Lake NY
Re: Binoviewing Deep Sky new [Re: Mike B]
      #5849867 - 05/09/13 11:46 AM

Quote:

Quote:

...when some low surface brightness object or the dim mag 13+ stuff will have me go back to mono-viewing, but not yet.



I'm thinkin' this varies by the observer, by the eye-brain combo of each individual.

There's no argument about the physics- the light pokin' thru each half of a BVer will be less-bright than before it was "split". But the summation-effect... THIS is what varies person to person!

For me & my eyes+brain, i'm convinced that brain-summation nets me essentially all what was "lost" in the optical splitting. I've gone back & forth b/t bino & mono, same or close magnifications, and it's a rare event to see mono what i can't see bino... it's down to percentages of time a faint star is seen- 50% in/out averted versus 75%. That close!

Yet for others i'm sure they've found differently. And some of that might be aperture-dependent?... a small scope showing the difference more profoundly? I dunno... haven't tried BVing anything less than 10-inches. 'Tis been 15-inches the past five years...





My experience is that bino reduction in deep sky brightness is more apparent with smaller scopes. Ive gotten to the point where I only use my Denk II for solar/lunar/planetary with my 5-inch refractor and 6-inch reflector. I find the reduction in deep sky brightness too objectionable on these scopes, where Im pushing my 5-inch APO down to mag 12 galaxies from my front lawn. On the other hand (other scope?): I use the bino 2/3 of the time with my 20-inch Dob. The main reasons why I would not go bino with the 20 are: not enough time to put the bino together or Im dealing with a lot of public or Newbie friends.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Binoviewing Deep Sky new [Re: George N]
      #5850161 - 05/09/13 02:34 PM

Totally agree, George! Each group type & size has a "critical-mass" aspect where the BVer adjustment curve becomes too steep to be functional.

Quote:

My experience is that bino reduction in deep sky brightness is more apparent with smaller scopes.



Yes, i've heard this frequently, and tho i haven't experienced it for myself, it's not too hard to imagine WHY it might be so...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: Binoviewing Deep Sky [Re: George N]
      #5850249 - 05/09/13 03:11 PM

Quote:

My experience is that bino reduction in deep sky brightness is more apparent with smaller scopes.




Apparent, maybe, but in percentage, it's exactly the same, regardless of aperture, of course. The reason it's felt more with a small scope is that the usual objects we observe, the Messiers and bright NGC, are closer to the observable limit in a small scope than they are in a big scope.

Despite this, I still feel that many objects show up well in a small scope with binoviewer. Especially if said scope has a fast f/ratio so that it can get quite a wide field of view even with a binoviewer. My 72/430mm ED can give a 2.3 field at 21.5x with a pair of 25mm Zeiss eyepieces with 50 AFOV or a 2.4 at 27x with a pair of 20mm 65 AFOV GSO Superviews. The views of the brighter galaxy clusters and groups from a dark site are amazing.


Clear skies!
Thomas, Denmark


Post Extras: Print Post   Remind Me!   Notify Moderator  
GlennLeDrew
Postmaster
*****

Reged: 06/18/08

Loc: Ottawa, Ontario, Canada
Re: Binoviewing Deep Sky new [Re: Astrojensen]
      #5850386 - 05/09/13 04:20 PM

Thomas is quite correct; it's not the smaller aperture itself which is the problem, but rather the targets we're seeking. If the object is suitably larger/brighter for the reduced aperture, the view is just fine.

For example, supposing for the moment a 'typical' surface brightness profile for galaxies...

If the 10" with BV allows to enjoy viewing them to, say, 11m and 2', a 5" would provide equally good views of galaxies to 9.5m and 4'.

The half-size aperture has half the resolving power and hence, for given object surface brightness, a doubling of the minimum object size. And the 1/4 light grasp increases the faintness limit by 1.5 magnitudes.

Naturally, if one strives to glimpse the same small and faint objects with a smaller aperture, the view suffers. But scaling back to a suitable degree on object selection, a BV is useful with *all* apertures.

A BV does not by some optical alchemy introduce dimming which increases ever more rapidly with decreasing aperture. The ratio of dimming is constant.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Binoviewing Deep Sky new [Re: GlennLeDrew]
      #5850601 - 05/09/13 06:22 PM

Agreed. A BVer confuses our sense of what we're after in viewing... it "splits" the resolution (based primarily on aperture) from the "brightness" (now diminished by the BVer's delivery to TWO eyes).

So the 10-inch scope still offers the endearing resolution of a 10" optic, at a cost of "diminished brightness"- that of a 7" scope, still significant. Whereas the lesser resolution of a 3" scope, already limited, is now asked to endure further limitation- the brightness of a 2.1" scope- ?

This seems to me much like the old saying "a 12-inch scope is the largest of the small scopes, and the smallest of the large scopes". It's a perceived threshold that has no mathematical logic, yet almost everyone knows what is meant- and might even "agree" with the statement.


Post Extras: Print Post   Remind Me!   Notify Moderator  
johnnyha
Postmaster
*****

Reged: 11/12/06

Loc: Sherman Oaks, CA
Re: Binoviewing Deep Sky new [Re: Mike B]
      #5850735 - 05/09/13 07:24 PM

I would respectfully disagree that a good binoviewer cripples a 10" scope with only the brightness of a 7" scope - basically half the mirror size. I think with a good binoviewer that has a premium beamsplitter like a MkV or Binotron 27 the view is *a little* less bright but there is to my eyes much more information from the summation effect of two eyes, and most of the brightness is also restored. And also to say that the equivalent, my 6" APO with binoviewer is only as bright as a 4" in mono vision, is simply not my experience.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Binoviewing Deep Sky new [Re: johnnyha]
      #5850820 - 05/09/13 07:56 PM

Well, it's just the physics of it. Pi-r-squared over two. So each eye *IS*, unquestionably, seeing the effective light of a 7" scope (from a 10" pre-split primary, anyhoo ).

But i totally agree with you- the summation effect of both eyes, via the BRAIN, is equally real... not exactly "physics", but human physiology.

Whether that "summation-effect" restores the brain's perception to 90%, 95%, or 99% will be somewhat individual. Count me somewhere b/t 95 & 99%.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: Binoviewing Deep Sky new [Re: johnnyha]
      #5851322 - 05/10/13 03:36 AM

Quote:

I would respectfully disagree that a good binoviewer cripples a 10" scope with only the brightness of a 7" scope




But that's what it does. Period.

Now, how we PERCEIVE things, that is where it's getting interesting: Because the brain now has twice the signal to noise ratio to work with, the S/N ratio is improved by 1.4, which is equal to a 0.37 magnitude increase. The result is that, on a binoviewed 10", while each eye sees only an image as bright as that from a 7.1" scope, The image looks as bright as if it was seen through a 8.5" scope. We really do get some of that light back, after a fashion. Not all of it, but at least some.

And it should also be noted that the extremely improved ergonomics for some people more than make up for the loss of light, much like when we can see more by sitting comfortably by the scope, rather than standing. Just like it takes some concentration to stand upright (even uncounciously) it also takes some concentration to just use one eye to look through an eyepiece. Looking with both eyes is natural and takes much less concentration.

All in all, this explains why some people hardly, if at all, notice the light loss and may even strongly prefer the binoviewed image, even on faint objects.


Clear skies!
Thomas, Denmark


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sorny
professor emeritus


Reged: 03/15/12

Loc: Southern MN
Re: Binoviewing Deep Sky new [Re: Astrojensen]
      #5851732 - 05/10/13 10:37 AM

I'm one that strongly prefers binoviewing on any targets that fit the FOV I can get with the binoviewer.

Most nights, I use 1 pair of eyepieces all night in my binoviewer. I may be flipping the power switch between reducer/none/barlow, but only on the most challenging or largeest targets does my binoviewer come out and the 38mm Titan go in.


Post Extras: Print Post   Remind Me!   Notify Moderator  
REC
Post Laureate
*****

Reged: 10/20/10

Loc: NC
Re: Binoviewing Deep Sky new [Re: Sorny]
      #5851777 - 05/10/13 10:57 AM

If you don't mind asking a side question, I see you have the WO's BV as well. I just bought the Denk S2 and I have not been able to use them yet going on two weeks of bad skies.

Do you see much difference in them over the WO BV?

Hopefully I will have a chance to compare them next week if it ever clears up here? I will be using it my 8" SCT.

Thanks,

Bob


Post Extras: Print Post   Remind Me!   Notify Moderator  
johnnyha
Postmaster
*****

Reged: 11/12/06

Loc: Sherman Oaks, CA
Re: Binoviewing Deep Sky new [Re: Astrojensen]
      #5852089 - 05/10/13 02:01 PM

Quote:

Quote:

I would respectfully disagree that a good binoviewer cripples a 10" scope with only the brightness of a 7" scope




But that's what it does. Period.



Yep. If you completely ignore summation and only view through one side that is indeed what it does.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: Binoviewing Deep Sky new [Re: johnnyha]
      #5852117 - 05/10/13 02:15 PM

Quote:

Yep. If you completely ignore summation and only view through one side that is indeed what it does.




Indeed, but we've got two eyes to use them both, true? We want to add up the light

Arguably, binoviewers work better than what math and dry theory suggest they should, IMO.


Clear skies!
Thomas, Denmark


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mike B
Starstruck
*****

Reged: 04/06/05

Loc: shake, rattle, & roll, CA
Re: Binoviewing Deep Sky new [Re: Astrojensen]
      #5852135 - 05/10/13 02:30 PM

Quote:

binoviewers work better than what math and dry theory suggest they should, IMO.




Of course they do... it's not the dry theory that's the issue, but rather the wet practicality at the tail-end of the optical assembly.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Kent10
scholastic sledgehammer
*****

Reged: 05/08/12

Re: Binoviewing Deep Sky new [Re: Mike B]
      #5852172 - 05/10/13 02:48 PM

This is a follow up to my testing of sharpness in binoviewing vs mono. I had thought when using my 2 Leica ASPH in my Mark V that it wasn't as sharp as mono but this is what I discovered this morning.

I was using extensions on my Leicas because light was coming in through a hole on the right eyepiece holder and getting into the bottom of the eyepiece. Now both eyepieces were bottoming out and this eliminated the glow from the hole in the Mark V but I noticed the depth of the eyepiece holders on the Mark V are different. I normally have my left eyepiece adjusted so it sits higher because my eyes are different. I noticed the right was actually higher and that is why objects weren't looking quite like they should with the Leicas. I can adjust them to be the correct distance but it is not convenient because then it is wrong for other eyepieces. I am glad I noticed this though because I couldn't quite get my Leicas sharp enough in the Mark V and I know they are sharp in mono. Now I know why I was having the trouble.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Sorny
professor emeritus


Reged: 03/15/12

Loc: Southern MN
Re: Binoviewing Deep Sky new [Re: REC]
      #5852899 - 05/10/13 10:34 PM

Quote:

If you don't mind asking a side question, I see you have the WO's BV as well. I just bought the Denk S2 and I have not been able to use them yet going on two weeks of bad skies.

Do you see much difference in them over the WO BV?

Hopefully I will have a chance to compare them next week if it ever clears up here? I will be using it my 8" SCT.

Thanks,

Bob




I get much more enjoyment out of the binoviewer now that I can get multiple magnifications with the flip of a switch. I think a power switch is the 2nd best accessory for a scope, after a binoviewer.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | (show all)


Extra information
2 registered and 2 anonymous users are browsing this forum.

Moderator:  TG, Geo557 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 1985

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics