Binoviewer change of heart...

[ollypenrice]

I've never got on with binoviewers but last night we put a guest's Baader unit, 2x AP barlow and two 13 Ethos EPs into our TEC.

Jupiter was devastating, as good as I've ever seen it in anything and possibly better. Once the diopter was right it was very relaxing.

On the stars it was also nice but I think it brought a tiny touch of CA with it. Not dead sure about that. There is certainly none in the TEC.

Olly

[philj]

Aha we have another convert, welcome to the 2 eyed side Olly

I have TMB binoviewers and use them with TMB planetary eps and I much prefer the two eyed observing to single its just so much more natural.

Try lunar its spectacular and almost 3d

Philj

[Charon]

I have the Williams Binoviewers but not too sure about them at the moment. When I was observing the Moon the craters seemed to be inside out (I was not drinking either), so I looked away started again and things were normal then blinked and inside out craters again tell me that I am not going nuts it was a weird experience!

[Merlin]

The brain can sometimes find it difficult to differentiate between convex and concave. I've experienced this effect too and we can also get it from looking at photos.

The effect isn't intrinsic to binoviewers, it can be experienced with monovision too.

[jimmyjamjoejoe]

Anyone tried the antares ones? They come with 2 pairs of super plossls for £205

[Steve]

I have the Williams Binoviewers but not too sure about them at the moment. When I was observing the Moon the craters seemed to be inside out (I was not drinking either), so I looked away started again and things were normal then blinked and inside out craters again tell me that I am not going nuts it was a weird experience!

It isn't the binoviewer, it is the way your mind processes the view. Something about the angle of light. If you were able to turn the view 180 degrees the inside-out craters would pop back into their correct perspective. (I am straining my memory here but I 'think' it is because our brain expects to see things illuminated from above and off to one side).

I suppose you could say it is the binoviewer, but only because it is allowing you to observe with both eyes.

HTH

[Ben Ritchie]

I've never got on with binoviewers but last night we put a guest's Baader unit, 2x AP barlow and two 13 Ethos EPs into our TEC.

Jupiter was devastating, as good as I've ever seen it in anything and possibly better. Once the diopter was right it was very relaxing.

I've always been afraid to try binoviewing, in case I like it too much and had to start doubling up on the eyepiece collection - one set is expensive enough. One time I got as far as buying one used, only for the seller to pull out, but I suspect a good binoviewer would work very well with the AP130 too...

[ollypenrice]

I certainly get the inside out crater effect in monocular viewing. It's very strange and inverts itself when I look away.

Olly

[philj]

Anyone tried the antares ones? They come with 2 pairs of super plossls for £205

Yes the Antares are a good intro to binoviewers I used them for years, came with a pair of 25mm and a pair of 10mm plossls. Not the best but good value for money. Can be a bit delicate though, mine soon had stripped threads on the ep locking screws. The ones I had suffer a little with wider fov eps but as I used them mainly for planetary it didnt matter too much.

Philj

[matsey]

I've got the Williams Optics ones, and the views on the planets is just incredible. Viewing Jupiter I see much more detail through the binos, and the Moon... just wow ! Hard to fully describe really, but it actually makes me kind of dizzy, like I'm floating just above the surface - it's quite amazing.

On the slight downside though, I'm not really enjoying them so much on deep sky objects and star fields... the view for me is quite substantially darker and the stars dimmer when compared to using a single eyepiece. Not sure I completely understand why, perhaps something to do with the eyepiece being that bit further away from the scope so I'm losing a lot more light? I also wonder if the aperture size doesn't help in this... maybe if (when!) I upgrade to something larger than a 6" scope, this effect won't be quite so obvious?

Regardless of that though, for me they're worth it for the planetary views alone, and using two eyes is so much more comfortable, I really do love them

[michaelmorris]

From my experience, the target where binoviewers really pay off is the Moon. The views are simply stunning. From my experience, the mountains look higher and the craters look deeper. This is probably to do with significant increase in contrast that you get with binoviewers. In my view, if you are serious lunar observer it really is a matter of which binoviewers you get, not should you get them.

[Peter Drew]

The reduction in brightness when using binoviewers is due to the beam splitting arrangement. This often results in a 60/40 split and being as the brain does not recombine them the brightness falls to 60% with a slight apparent increase due to two signals as opposed to one signal and one noise. This reduction is actually quite beneficial in respect of bright objects like the Moon and planets, the Sun in white light is also spectacular in binoviewers.

[matsey]

The reduction in brightness when using binoviewers is due to the beam splitting arrangement. This often results in a 60/40 split and being as the brain does not recombine them the brightness falls to 60% with a slight apparent increase due to two signals as opposed to one signal and one noise. This reduction is actually quite beneficial in respect of bright objects like the Moon and planets, the Sun in white light is also spectacular in binoviewers.

Thanks Peter, that's a really helpful explanation, makes perfect sense. The Sun is actually the one object I haven't had an opportunity to view from the binoviewers yet. I do have a solar filter though and following your comments, I'm even more looking forward to that now - definitely a "todo" for this weekend for sure

[Merlin]

I'm not sure what peter means when he says that the brain doesn't recombine the split images in a binoviewer.

If this were so, we'd see two images of the same object. As I understand it, the reason that less light reaches the eyes from a binoviewer is because of the sheer amount of glass the light path travels through.

[great_bear]

He means it doesn't sum the light levels.

Look around you and close one eye - your vision doesn't suddenly get half as bright, does it?

So binoviewers - dividing the light between both eyes - cause a significant drop in brightness which is not corrected merely by virtue of having two eyes.