Should I upgrade my binoviewers?

[RobertI]

I bought a William Optics binoviewer a couple of years ago and it has transformed by observations of planets, moon and sun. I have also recently tried it for deep sky and have found it very promising, but one thing that has bothered is that the right eyepiece view is dimmer than the left eyepiece view. For planets and moon this is less noticeable but for dimmer objects it's annoying. I've not seen many others commenting on this, but recently read this article by Bill Paolini that indicated he had the same issue with his WO BVs (indicating its likely to be a result of the design of the BV), and that the Baader Maxbright IIs didn't have the same problem. I'm seriously considering getting a pair of these Baaders Maxbrights now.

Has anyone else had this issue with the William Optics BVs? Has anyone upgraded to the Baader Maxbright IIs and what did they think? Any thoughts appreciated.

Edited March 5, 2022 by RobertI

[jetstream]

2 hours ago, RobertI said:

but one thing that has bothered is that the right eyepiece view is dimmer than the left eyepiece view

Its "polarization" - an issue with some prisms and can be common. I checked my Binotron 27's and there was just perceptible difference- and they show no difference on the moon for example. Denis over CN had a good convo on this buried in a long thread of his regarding binoviewers etc.

Edited March 5, 2022 by jetstream

[Highburymark]

Even the expensive MkV Baader binoviewer shows strong polarisation, so as Gerry says, it’s a common feature with prism binoviewers. I haven’t noticed any with the Maxbright II though. 
More generally, although the WO BV is excellent, the Maxbright is a very nice upgrade - wider fov, clicklock EP holders, T2 connections with option to use GPCs. Just difficult to find in stock at the moment.

[Ricochet]

If you think you might want the Maxbright IIs it's probably worth contacting FLO to see if they could advise you how far down the waiting list you would be. The last I heard they were expecting stock to arrive in the next month or two but there are 18 month's worth of backorders to fulfil first.

[RobertI]

Thanks @jetstream, @Highburymark and @Ricochet  very interesting to hear that it’s polarisation and is fairly normal, it is annoying though. Given how much I like binoviewing it sounds like the Maxbrights would be a great upgrade. Shame about the stock shortage, I will check with FLO as suggested. 👍

[Paz]

I have Maxbright 2s and different polarisation isn't an issue that bothers me  when observing, and I observe anything / everything with them.

[RobertI]

1 minute ago, Paz said:

I have Maxbright 2s and different polarisation isn't an issue that bothers me  when observing, and I observe anything / everything with them.

Thanks @Paz good to know. Is there no polarisation at all, or is it there but doesn’t bother you?

[Paz]

Just now, RobertI said:

Thanks @Paz good to know. Is there no polarisation at all, or is it there but doesn’t bother you?

I will check later today and feed back, it might be something I notice if I go looking for it and otherwise don't notice. I do solar observing with a Brewster angled Herschel wedge that polarises the light quite strongly and I wonder if incoming polarised light would exacerbate the problem but I don't notice a detrimental effect then.

[MalcolmM]

@RobertI, great minds! Not only the Baader zoom but the Maxbright too! I've got the WO Binoviewers, love them when they work but every now and then I find I simply can't get the images to merge. I reckoned the self centering click locks on the Maxbrights might help here. That's a very good review you linked to. Thanks for sharing it. If FLO get back to you on the stock situation please let me know!

Malcolm

[Paz]

I've had a look and yes the right side looks slightly dimmer than the left. I had a go at capturing it on camera but that doesn't show any difference.

If I hang back half a metre or so from the eyepieces to see both exit pupils side by side I can tell but it's slight. If I go up to the eyepieces and look through its tough to tell there's a difference. 

[RobertI]

39 minutes ago, Paz said:

I've had a look and yes the right side looks slightly dimmer than the left. I had a go at capturing it on camera but that doesn't show any difference.

If I hang back half a metre or so from the eyepieces to see both exit pupils side by side I can tell but it's slight. If I go up to the eyepieces and look through its tough to tell there's a difference. 

Thanks for that, very interesting, I will have a look at my WO BVs in daylight just out of interest to see how obvious it is. Sounds like the Maxbrights have a similar design to other BVs but have managed to control the polarisation effect better?

1 hour ago, MalcolmM said:

@RobertI, great minds! Not only the Baader zoom but the Maxbright too! I've got the WO Binoviewers, love them when they work but every now and then I find I simply can't get the images to merge. I reckoned the self centering click locks on the Maxbrights might help here. That's a very good review you linked to. Thanks for sharing it. If FLO get back to you on the stock situation please let me know!

Malcolm

I certainly will.  

[jetstream]

2 hours ago, Paz said:

I will check later today and feed back, it might be something I notice if I go looking for it and otherwise don't notice. I do solar observing with a Brewster angled Herschel wedge that polarises the light quite strongly and I wonder if incoming polarised light would exacerbate the problem but I don't notice a detrimental effect then.

2 things- I never use my prism diag with the Binotrons as "stacking" prisms might not lead to the best results IMHO. A little tidbit- years ago I discovered that a Baader single polariser filter works great with my Quark, enhancing contrast in Ha.

I must add that for white light solar the Baader Cool doesnt seem to impact the views through the binos, so I guess I do "stack" prisms... I was referring to the moon and planets in the above comment.

Edited March 5, 2022 by jetstream

[Deadlake]

I surprised no one has mentioned the CZAS BV’s.

https://www.cloudynights.com/articles/cat/user-reviews/field-test-carl-zeiss-apochromatic-sharpest-czas-binoviewer-r3282

read the review…

[RobertI]

44 minutes ago, Deadlake said:

I surprised no one has mentioned the CZAS BV’s.

https://www.cloudynights.com/articles/cat/user-reviews/field-test-carl-zeiss-apochromatic-sharpest-czas-binoviewer-r3282

read the review…

Thanks for the link, I shall have a read, looks interesting. Seems to retail for about £1000 so probably beyond my budget, but you never know…..

Edit: Just read the article in full. It looks like Bill Paulini likes the CZAS BVs a lot, on a par with the Maxbrights with a very slight advantage at high powers on planetary. Does that sound fair?  I imagine the CZAS’s are theoretically better when used with faster scopes, but Bill used an F8 triplet in this test. My scopes would be an F7 doublet and F10 SCT. 

Edited March 5, 2022 by RobertI

[Highburymark]

Yep - no polarisation with the Zeiss pair. They are slightly sharper at high magnifications, and don’t need a barlow/gpc to correct aberrations, but the difference with the Maxbright II is subtle, at least that’s my experience so far. I have a lot more testing to do with a 4x Powermate I’ve bought recently, which is superb, and a great way to ramp up the power. But I’ve had five pairs of BVs now (WO, Baader MkV, OVL, Maxbright II and Zeiss Apo), and the on-axis views are similar. The biggest contributing factor to poor views with binoviewers is not how much they cost - it’s how well they’re collimated.

[RobertI]

1 hour ago, Highburymark said:

Yep - no polarisation with the Zeiss pair. They are slightly sharper at high magnifications, and don’t need a barlow/gpc to correct aberrations, but the difference with the Maxbright II is subtle, at least that’s my experience so far. I have a lot more testing to do with a 4x Powermate I’ve bought recently, which is superb, and a great way to ramp up the power. But I’ve had five pairs of BVs now (WO, Baader MkV, OVL, Maxbright II and Zeiss Apo), and the on-axis views are similar. The biggest contributing factor to poor views with binoviewers is not how much they cost - it’s how well they’re collimated.

Thanks Mark, did you notice whether some of your binoviewers were significantly worse on   left/right brightness than others? Did you find any of them bothersome in that regard? I can live with the issue in the WO’s, but I’d pay money to make it go away. 

Edited March 6, 2022 by RobertI

[jetstream]

3 hours ago, Highburymark said:

The biggest contributing factor to poor views with binoviewers is not how much they cost - it’s how well they’re collimated.

Excellent point Mark.

Its hard to merge or hold merge without vg collimation. Ditto for poor EP holders. When the binos were bought I splashed out on the collimation tool- which I've never had to use but the instructions made it sound easy if need be.

To me the real test of equipment is not feeling the need to keep trying other things out and the binos I have satisfy me.

[RobertI]

8 hours ago, RobertI said:

Thanks Mark, did you notice whether some of your binoviewers were significantly worse on   left/right brightness than others? Did you find any of them bothersome in that regard? I can live with the issue in the WO’s, but I’d pay money to make it go away. 

I’ve just realised you indicated further up that the Maxbrights didn’t show any noticeable left/right difference, which is probably what I needed to know. 👍

[Highburymark]

14 hours ago, RobertI said:

Thanks Mark, did you notice whether some of your binoviewers were significantly worse on   left/right brightness than others? Did you find any of them bothersome in that regard? I can live with the issue in the WO’s, but I’d pay money to make it go away. 

The worst were the Baader MkV, then WO/OVL which are possibly made on the same production line. It didn’t bother me much tbh, but am sure you’d be happy with the Maxbright II. Might even be worth asking Baader about it - they are very good at responding via the website.

[Deadlake]

15 hours ago, Highburymark said:

Yep - no polarisation with the Zeiss pair. They are slightly sharper at high magnifications, and don’t need a barlow/gpc to correct aberrations, but the difference with the Maxbright II is subtle, at least that’s my experience so far. I have a lot more testing to do with a 4x Powermate I’ve bought recently, which is superb, and a great way to ramp up the power. But I’ve had five pairs of BVs now (WO, Baader MkV, OVL, Maxbright II and Zeiss Apo), and the on-axis views are similar. The biggest contributing factor to poor views with binoviewers is not how much they cost - it’s how well they’re collimated.

Regards CZAS vs Baader. I've read you can use 5-7 mm EP's with the CZAS, how do the views compare with a Barlow in front of the diagonal using a Baader?

Convergence in both cases will be difficult....

[Highburymark]

My shortest eyepiece pair for binoviewing are 11mm Delites. No problems merging. Never tried anything below that.
I mostly use BVs for solar Ha, and like to use several pairs of eyepieces for each session (often swapping between 11mm/15mm/18.2mm and 25mm), to move from full disc to individual features. I like to be able to manipulate magnifications easily. With the Baader BV, a combination of 1.7x GPC and AP Barcon works well, but I pretty much always put the Barcon after the diagonal, using T2 spacers to adjust power. With the Zeiss Apo, I’ve tended to just use a 2.6x GPC fixed to the diagonal, and use different eyepieces to move between 60x and 140x - so again haven’t much experience with barlows before the diagonal/on the telescope side. Have read lots of CN reports of Barcon/Baradv working well in that format though.
So far very impressed by the 4x Powermate for lunar - getting about 160x with best 25mm eyepieces on the Moon with Zeiss BV. 

[jetstream]

I can merge down to 9mm eyepieces but I start "fighting the merge". My best high power set up is the 12.5mm Tak orthos (18's are vg too) which gives about 330x in the 15" and I must say that the views of Jupiter with this set up under good conditions is jaw dropping. Saturn too.

Lower power binoviewing the moon is a favourite sport though.

[RobertI]

5 hours ago, jetstream said:

Lower power binoviewing the moon is a favourite sport though.

Yes I also discovered how enjoyable this is. And also low power viewing of the FULL moon - who would have thought?