Binoviewer EP pairs tested (finally).

[Dude_with_the_tube]

i have finally managed to rack up some 8+hrs of testing (thanks to weather),i think this should be sort of sufficient to do some conclusions of what is staying and what is going from the array of eye pieces i have,might also help some other folks who are considering going binoviewer route,so carry on reading if you are interested in this,for people sticking to cyclops mode,this topic will be irrelevant.

Lets start from begining.

Telescope used:Vixen 150 ED (6 " F9 ED refractor)

Binoviewers: Denk 2 with power switch removed.

Diagonal: Zeiss 2" prism 

No OCS or Barlows used as i can reach focus with binoviewers in native focal length.

Targets:

M45: M44;M42+ Trapezium;Jupiter,Moon,Venus,couple of double stars.

Eye piece pairs:

Maxvision 24mm 68 deg (outer casing removed)

Maxvision 16mm 68 deg

Meade Research grade pairs of  28mm ortho and 20mm Erfle

Baader genuine Orthos 5-18mm pairs

Here is the pic of the gear:

Observations where done through out 4 session and targets where kept the same.

Lets start .

Maxvision 24mm.

Firstly i had to remove outer casing as with casing on i could not get my nose in between the Ep`s.Takes only 2 mins to do it and you can re-install afterwards if required.Links on how to can be found on net and it is a straight forward thing.

However,even with casing removed,i am still struggling to get perfect position.I wonder is Panoptics or Ex Sc are slimmer? Who ever has a 24mm Pan or 24mm exSc in 68 deg (NOT 82) could you measure the diameter of the body and post here please?

I am actually impressed with performance of this Ep.Used for low powers and views provided on M45;44 and 42 where sharp with only 2% astigmatism on the edge.And then i had to really look for it.If you dont pay attention on that then the views are actually clear and crisp.Stars are pinpoint across the field only the remaining 2% starting to become "comets".Not bad.M42 or Orion nebulae is a sight to behold.All in all,if your binos have 26mm+ prisms,deffo worth considering as alternative to ExSc or Panoptics for low powers.EP has a very slight field curvature,but not off putting,only noticeable when panning.Works very well with OCS or barlows if you cant reach focus in native mode.

Maxvision 16mm.

I think this was the dark horse and havent tried other focal length of Maxvisions apart of 24mm,i would say that 16mm is sharper and better then 24mm.I didnt use the screw up eye guard as  i found it uncomfortable and used the pair with the body not twisted up (as it is in pic).Will talk about eye relief later.

I can frame half disc of moon with this EP,Orion nebulae fills whole view and is beautifully presented.Too low power for Venus,but usable for Jupiter and as i mentioned,EP gives nice and sharp views in bino.Very comfortable to use and i actually really liked the 16mm.One thing what did surprise me.Maybe it was me,but one of the 16mm Ep`s fogged up.No any other pair did that during all observations,only the 16mm one did it on last observation.Cold be the cold weather and heat of eye?other than that i cant fault it.Again,works very well with OCS and Barlow with no image degradation.Noticed a slight color fringe on the limb of the moon.

Meade Research grade pair.Well,it is very difficult to find them at first place and if you are a planetary observer and see one coming up for sale,get them without thinking.These Eps are simply stunning.Slightly more price wise as the BGO`s but after many comparisons,i have found that Meade Rg`s are slightly outperforming BGO`s on critical detail.Not by mutch but it is there.

anyhow,pair of 28mm RG orthos.Very generous eye relief.I mean 20mm+ what means you can use glasses with these if needed.Eye placement is important as due to large eye relief you will get black outs,but once mastered,this EP for low powers is superb.Field is flat like a back of flat iron.Background is pitch black.Orions nebulae now shows a lot of nebulosity and actually it is sort of dramatic view of the wings spread across the black sky.M44 and M45 both show nice pin point sharp stars.Only draw back:as it is an ortho ,EP only has 45 deg FOV.Really a shame,but other than that its a beauty.Half moon is razor sharp,no false colors,just joy to use.A direct alternative would/could be Edmund optics RKE28mm.

Meade RG 20mm Erfle. gives about 60-65 deg FOV and can actually be found second hand.These do appear time to time and i can strongly suggest to get a pair for your binos.Same as the 28mm ortho,it is razor sharp,flat field,sharp across with no astigmatism or any other issues.Again,generous eye relief and actually more user friendly as the 28mm orthos with they mammoth eye relief.Feather light! Barlows like there is no tomorrow.And can actually be used as your only pair if you have a combos of Barlow options.I tried options with OCS giving X1.25 and also 2x barlow and there was no issues at all.Image was still bright and crisp with no loss of critical detail.

BGO`s.mutch discussed Ep.Loved by many,hated by few.I only observed 3 targets with these:Jupiter,Moon and Venus.

Sorry,18mm was used on M42.It was lovely but having also a pairs of 20;24 and 28 i didnt see the need of critically testing the 18mm and quickly moved onto other focal length.

I went all the way down to 5mm pair.Yes you are reading correct. pair of 5mm BGO`s where used on Moon.I felt like astronaut walking on the surface! If you have never tried binoviewers,i suggest you do it is a whole new experience.Venus in pair of 7mm BGO`s is actually more then just a bright round thing.I could actually see the belt of Venus.Never managed to see it cyclops mode as Venus was always too bright.

Jupiter,despite seeing conditions where not the best,still,gave up his main belts and aditional 2 belts with a lot of detail on sides.Followed Io`s shade on the surface of Jupiter for a while.Lovely.

Back to Moon.I had to do it.12.5mm followed by 9mm;7;6mm still sharp and masses of detail.Alpine Valley,Caucasus and Apennine Mountains,Mare Serenitatis,Rilles and Ridges,all these became a new meaning in binoviewers.Simply breath taking.5mm BGO goes in,and not we have landed on surface.Amount of detail is incredible.If you dont see it immediately,keep looking for 2 more mins and the detail pops up.Like magic.I was touring on the top of the mountains,following the Rilles,checking out craters until.... My eyes started to freeze.Hands have been cold and i couldnt feel my fingers.And this is the issue with BGO`s.Need rubber eye guards or you will freeze your eye sockets.That cold metal just eats you.This is the only down side of flat tops.Edmund optics sell different types of eye guards.Not blumming cheap for a piece of rubber i tell you,but i like my eyes and i would like to keep them as they are for a long while,as such i will need to find a pair of rubber eye guards quick!

And now note about eye relief.One thing struck me.5-7mm orthos are quite tight on eye relief.Well,try using them in binoviewers.you will be surprised how comfortable you will be now.No eye relief issue at all.

So there we are.Planetary,bright DSO`s and binoviewer works.I am now converted into binoviewing and loving it.No cyclops.I dont see the need of it.Try it.you might love it same as I do or you might hate it,but if you dont try,you will never know.

To re-cap.

Maxvision 24mm: need to remove casing,2-3% astigmatism on outer edge,slight field curvature,a bit bulky,but if your interpupilary distance is slightly above average,worth considering as cheaper alternative to panoptics or Ex Sc.Are my ones a keepers? Not sure yet.

Maxvision 16mm: lovely crisp images,great EP,comfortable and compact.This one is a keeper.

Meade RG`s. Love them and will try to find other missing focal length`s.Could be a long shot,but worth it.

BGo`s.Gorgeous.Plain and simple.Need rubber eye guard,but other than that there are no faults.Optically perfect.

There we are.You have my confession.From ortho purist i have become binoviewer addict.

Now whilst writing this,i have been thinking of other possible bino pairs.TV plossls,Naglers,Delos,Ex Sc 82 degree range in shorter focal length.Actually,the most discussed eye piece:BST Starguider.how about them? This is a new minefield we are stepping in....

Clear skies.

[Saganite]

I share your enthusiasm/ conversion to binoviewers. I have the WO viewers with the 20mm eyepieces supplied with it, and I simply

cannot believe the experience they give observing the moon, stunning! I had to put 65 mm of extension to reach focus in the 12" Lightbridge

and with the 1.6x barlow supplied I am not sure what magnification I am getting but comparing the view I get with my 8mm LVW 

It would seem to be190x. That would suggest  that the barlow is increased from 1.6x to 2.5x. Is that possible?

There must be a way to calculate it.

I then tried a pair of Televue 10.5 plossls and though the magnification was mightily impressive I could not achieve a sharp focus. I will

try them later in my ED100

I am seriously reconsidering my eyepiece case now, thinking that 3 pairs of decent eyepieces will suffice.

[Dude_with_the_tube]

your 100 ED will be nice with binoviewers,also WO binos have a great potential.I dont have any knowledge of binoviewing with dobs,but i have red that a lot of people have done it and reports are stunning.It is a possibility that due to increased focal length that barlow becomes 2.5,but i will not give the word for that.I think the way around to reach focus with binos on dobs where to move your primary up the tube closer to secondary (shorten focal length),then you should be able to reach focus with out barlows.that should be some experience to look through binos in 12" dob!

Most common Ep pairs for binos: 24-28mm for low power, something in 16mm range for medium and 7-9 for high powers.Also all depends on how big are the prisms on your bino,this will determine your low power ability.WO have 23mm if i remember correct,as such 25mm ortho or plossl will be really the lowest one you could go.

Good luck!

[John]

I've used binoviewers with my 12" OO dob. It's the only one of my scopes that I could get them to come to focus with !

The view of the Moon was quite nice I seem to recall.

[Saganite]

The bino's do indeed work beautifully in the ED100, but i have to remove the diagonal and place them in the end of

the tube, which can literally be a pain in the neck.

I will not be bothering with the refractor tonight though, I am getting wonderful views of Jupiter as it is!

[denis0007dl]

Very nice report Dude!

ES 24mm/MV 24mm 68deg eyepieces have 28mm fiels stops, and in all Denk binos, including Binotron 27, you have little vignette because 26mm field stops.

I had Panoptics 24 and ES 24 in same time, and I can tell you that Pans are much slimmer, so there is much space for nose position, and Pans are lighter.

I actually prefeer much more RKEs 28 for binos, so I recommend you them to try.

Also, if you can get some Zeiss orthos 25mm (ZAO or special microscope ones), this will give you best possible performance. With best barlows and/or Powermates you will have ultimate performances, without short eye releaf problems!

[great_bear]

I am seriously reconsidering my eyepiece case now, thinking that 3 pairs of decent eyepieces will suffice.

Even three may be generous.

For "casual" astronomy I use my custom 150/F8 Newtonian with various EPs, but my Mak 180 (for "serious" study) I operate exclusively with just two pairs of eyepieces and (rarely) the WO OCA for a third, high-power, magnification.

The eyepieces I use for this are the 20mm and 14mm Meade Series 5000 Plossl pairs (which are not actually Plossls, but an Erfle derivitive). In most scopes I tell people to steer clear of these as they are a mess off-axis, but in the F15 Mak they are wonderful. I occasionally take a break using a single, monovision 24mm 5000 SWA (same as Maxvision 24mm) but most of the time the binoviewer stays in the focuser.

I've compared the Meade 5000 Plossls in the Mak with lots of top-end stuff; BGOs, TV Plossls, Radians and Brandons, and nothing comes close. This makes me real happy because - for the longest time now (two years plus?) - I've been able to cross off eyepiece selection for the Mak as "done" - something I never thought possible.

Of course, I do have to be sure the weather will hold before I break out the Mak - otherwise I just stick to the 150/F8 Newtonian (made by johninderby) abd Delos EPs, a setup which I can bring up / tear down in less than 30 secs either way.

[Dude_with_the_tube]

Thanks Deniss for the info on sizes,both my maxvisions will possibly going as I have a pair of 28mm Meade RG orthos what are goving me the same FOV and performance as RKE`s 28 if not better.And nope,i dont need any barlows as i am perfectly fine with all focal length Ep`s,including the ones with short eye relief.Got also a Parks 32mm Erfle incoming for real low powers if needed.

Maxvisions 16mm are going too as I have found meade RG Erlfes and these will replace them.

Jeremy, i agree with you on Meade 5000 series plossls,These are very very good ones and actually overlooked Ep`s,shame is that these do not come up very often on s/h market.I am using meade RG erfles too and I agree in fast scope these will suffer,but in F9 -F15 these are superb.

[PaulC-I]

Very nice report Dude!

ES 24mm/MV 24mm 68deg eyepieces have 28mm fiels stops, and in all Denk binos, including Binotron 27, you have little vignette because 26mm field stops.

I had Panoptics 24 and ES 24 in same time, and I can tell you that Pans are much slimmer, so there is much space for nose position, and Pans are lighter.

I actually prefeer much more RKEs 28 for binos, so I recommend you them to try.

Also, if you can get some Zeiss orthos 25mm (ZAO or special microscope ones), this will give you best possible performance. With best barlows and/or Powermates you will have ultimate performances, without short eye releaf problems!

I totally agree with Denis on this one. I use a Baader FFC or Televue 2" x2 powermate or Baader x1.8 2" multiplyers before the diagonal (T2 prism) (or before the bino when using a mak newt) and then I have the luxury high power views through pairs of Brandon 24mm, Zeiss 25mm microscope eps, Televue 20mm plossls and possibly down to Nikon Nav 17.5's when seeing allows. This way you do not maginify any aberations of the diagonal or binoviewer prisms and have the luxury of large eye lens to imerse yourself into.

Never been back to cyclops since! apart from an occasional glimse with a Pentax XW 30 for the odd low power sweep!!

[denis0007dl]

I totally agree with Denis on this one. I use a Baader FFC or Televue 2" x2 powermate or Baader x1.8 2" multiplyers before the diagonal (T2 prism) (or before the bino when using a mak newt) and then I have the luxury high power views through pairs of Brandon 24mm, Zeiss 25mm microscope eps, Televue 20mm plossls and possibly down to Nikon Nav 17.5's when seeing allows. This way you do not maginify any aberations of the diagonal or binoviewer prisms and have the luxury of large eye lens to imerse yourself into.

Never been back to cyclops since! apart from an occasional glimse with a Pentax XW 30 for the odd low power sweep!!

Paul, I am glad that you have same experience like mine. I spent many nights testing all premium eyepieces on binoviewers and alone (ZAO IIs, XWs, Pentax orthos, Zeiss monos, TMB and Siebert monos, Zeiss microscope premium orthos, Brandons), and find that premium magnifiers like premium barlows and/or Powermates produce best possible performance (sharpness, contrast.....). My two friends and I over here did many night testings, and all conclude same.

Especially on binoviewers, this gives huge advantage, because you get more comfort than using very short focal lenghts orthos.

[PaulC-I]

Paul, I am glad that you have same experience like mine. I spent many nights testing all premium eyepieces on binoviewers and alone (ZAO IIs, XWs, Pentax orthos, Zeiss monos, TMB and Siebert monos, Zeiss microscope premium orthos, Brandons), and find that premium magnifiers like premium barlows and/or Powermates produce best possible performance (sharpness, contrast.....). My two friends and I over here did many night testings, and all conclude same.

Especially on binoviewers, this gives huge advantage, because you get more comfort than using very short focal lenghts orthos.

Denis, It is good to hear that I am not alone in my discovery. I hope many bino users read this and try the same route to enlightment.

[Stu]

A great read Gaidis, sounds like you've been having fun up there.

Well, I have a Vixen, Denk binoviewers, 2" x2 PowerMate plus 2x 25mm Zeiss Orthos so me thinks I need to try them all together sometime soon!!

[Dude_with_the_tube]

A great read Gaidis, sounds like you've been having fun up there.

Well, I have a Vixen, Denk binoviewers, 2" x2 PowerMate plus 2x 25mm Zeiss Orthos so me thinks I need to try them all together sometime soon!!

i think you should Stu.I have been pleasantly well how to say not surprised but overwhelmed might be the right expression to say with the views so far.And have gone extra mile now.I have another full set of Meade RG`s located and these are on they way to me for binoviewer and there is also a new binoviewer ordered but about that later when i have it   

[F15Rules]

A great read Gaidis:).

One of the great things about using binoviewers in slow scopes is that even cheap eyepieces produced e good results.. my entire bv eyepiece set of 6 EPs (3 pairs) cost less than single new Nagler and deliver super, crisp sharp images.

I know having a tube shortened to use bvs without a Barlow seems drastic, but believe me it is worth it and a couple of simple extension tubes allow it to be used in cyclops mode in seconds.

For me, it's the sheer viewing comfort of bv's that I love..eyes are relaxed, they water less in cold weather and you can observe one object for longer and so see more. The only area I think cyclops may be preferable is in critical high power splitting of double stars, and possibly detection of very faint nebulae.

That's my two penn'orth anyway:)

Dave

[Dude_with_the_tube]

i completely agree with you Dave on almost everything you said

why almost? 

i agree on the cost,specially on long focal length instruments you can get performance out of simple kelners.I have seen through Naglers,but i just dont get the hype of them as such i only had one Televue EP in my case for short period of time and then i moved on,but this is not the discussion about Televues.Point is that yes you can walk away with cheaper EPs in bino and long focal length instrument and i agree on that one.

And i agree on the fact that despite sounding harsh of cutting the OTA it is totally worth it,only if you really like binoviewers.Try them first before you introduce your OTA to the chopping board.I didnt need to do that as the 4" focuser was so large,that the new focuser with custom adapter fitted in straight and i can binoview in native.I have to use 120mm extension to go cyclops,but after the last session i had,i actually doubt i will do so.

I also agree on statement of relaxed view etc.

But i disagree on on your last one about splitting doubles and faint nebulae.Binoviewers take away about 1" of your aperture or half a magnitude in other words.What means your scope will be 4" and my one 5".Doubles are bright and you dont really need large aperture to split them and by going native focal length you can use pairs of 5mm or even 4mm EPs if required or as mentioned above by Paul and Denis,you can use barlow or powermate to get magnification required.Neil English who is obsessed with splitting doubles (respect Neil!) ,he only uses 4" achro for doing that,as such,i dont think that by doing that with binoviewers you will be loosing out on something.More interesting is the faint nebulae.How faint do you mean? Obviously you know that for nebulae or DSo`s in this case we both do not have sufficient aperture anyway as such i think DSO`s are relatively irrelevant for us,apart of some bright ones where we only loose half a magnitude what i think is very little anyways.For real deep sky you will need larger scope and so far as i have read,people use binoviewers on large 20" + dobsonians on very deep sky with great sucess.As such,to sum everything up,i dont think yo uwill be loosing anything on doubles and if your interest is also DSO`s,get lets say a 10 or 12 ich dob,modify the focal length to be able to go native and you are in for a treat for DSo`s.I might do that at some point myself if something interesting pops up on s/h market.

Gaidis