Big vixen binoculars vs binoviewers

[GavStar]

I enjoy looking through my scopes but do find looking through one eye a bit uncomfortable and also have some issues with floaters at high mags. So I've been considering either binoviewers or some big binoculars. Binoviewers would be an obvious solution but they do seem a bit like marmite with very varied member experiences and this has made me think twice. In particular some experienced observers have decided to go back ditch their binoviewers. However big binoculars with interchangeable eyepieces are very expensive (eg kowa highlander) and there does seem to be collimation issues at higher magnifications.

The new vixen bt-ed70 is within budget but I guess would only go up to 50x or so and i cant find any reviews of it. I prefer looking at planets and the brighter dsos such as m42 which I think points more to the binoviewers.

Any views or comments welcome?

Gavin

[baggywrinkle]

If you are going to go down the bino route build into your budget a good tripod of parralleogram mount. and a chair. I like binos but they become a pain at high elevations and if they are big ones then good stable support is a must or the enjoyment level will drop.

I have bino viewrs and bins. They bino viewers can offer some really good views and reduce eye strain.but you do need matched ep's so they can have additional costs and you need to ensure (as with bins) the inter-ocular distance is good for you.

[Space Dragon]

It is a bit of a mine field. I have owned both a large 100mm 45º Helios Quantum 7 binocular and used binoviewers with different scopes.

Much depends on your viewing preferences and as such I've recently settled on a fast 6" refractor with a large aperture binoviewer and 68º EPs. This gives me a FOV of 2º, pinpoint right to the edge.

The 152mm objective gives the same light summation as a 100mm binocular.

I wouldn't recommend binoviewers with anything less than a 100mm refractor but YMMV as they say. They do dim the image, so it's important to keep it as bright as possible.

It also gives the option of higher mags than the binocular, which would be a maximum of around 70x, generally speaking, before collimation and small, dim exit pupils get in the way.

I've also used binoviewers with large SCTs with some good results but with a very narrow FOV. You have to be careful to keep the light path as short as possible otherwise you'll see vignetting and loss of illumination but I've had very good planetary views.

Lots of people binoview with a big Dob, which I haven't but it gives a wider FOV than the SCT and plenty of light to keep the image bright.

There's still a lot to be said for a quality large angled binocular and i nearly bought another one a couple of months ago but the Kunming ones are heavy and the wooden surveyors tripod, while it damps quickly, is not easily adjusted, it really requires a heavy duty crankable tripod, not cheap.

Even then it would still not be that comfortable at the zenith.

If you are into planets, you'll maybe want a longer focal length refractor to minimise CA, although this in turn will narrow the FOV.

With most binoculars of any size, you'll see a lot of CA on bright objects.

As far as cost goes, neither is a cheap option really, as after buying the 6" refractor, 26mm aperture binoviewer, T2 prism diagonal, Skytee mount and 2x24mm Panoptics, there's not much change from £2,000 [new that is] but that is about the cost of a big binocular new.

The Baader Maxbright bino is a great place to start, it's affordable and I'd recommend the T2 system with it, it keeps the light path short and is flexible, you can experiment with it.

The lowest power EPs to use with the Maxbright would be 25mm plossls and for high powers, maybe 12-16mm. It's always best to barlow a bino rather than use very short focal length EPs.

But the great thing this about this set up is I can go from horizon to zenith in relative comfort with the 90º diagonal, by the way, the large 90º binoculars have a stopped down aperture, due to the prism housing design, so some 100mm are only operating at 80-90mm, I'm not sure about the 70mm but someone on CN measured these at nearer 60mm.

These are the chinese Kunming offerings of recent years and the Vixen may well be different, I'm not sure.

Another advantage of using 90º is your face is never looking up into the night sky. It may seem like a small thing but I was finding with binoculars, I was getting a painfully cold face after a while from facing up into the winter sky, I am in Scotland as well but now I don't have that problem.

Any gear choice always involves some sort of compromise, optics, weight, ergonomics, cost, what it looks like,......and in an ideal world, I'd have an 8" AP Apo with Baader MkVs in an obsey AND a pair of Kowas and Fuji 150mm and Docters for fun but there's two chances of that happening....fat and slim....so I'm pretty happy with what I've got now.

I always remind myself how lucky we are to live in an age where all this astro gear is available and relatively inexpensive, compared to say 40 years ago........no chance.

Anyway, let us know what scope you have at the moment or you might have in the future and any more questions I might be able to help you with.

Cheers

[Space Dragon]

Have a look at these......this Star Party in Japan is something else.

http://soboe.web.fc2.com/2013/report/report2013.html

[Mark in Macc]

I use William Optics binoviewers with a C9.25 SCT and have 3 pairs of EPs from 25mm to 15 mm. Once set up they are great to use and very relaxing on the eye. The binos with one pair of EPs were £180. Nice if you can afford £2000 but can be done much cheaper if you want to.

[GavStar]

Many thanks for these responses.

My scope is an Equinox ED120 (f7.5) mounted on an iOptron Minitower 2. (I have a TV85 as well, but will stick with this as a grab and go rather than try binoviewers for this)

From your comments, it does seem like binoviewers would suit me better than big binos. I would like to aim to get up to 150x magnification, but also to have the option of reasonably widefield views as well. So in terms of focal lengths maybe a 12mm and 24mm set of eyepieces?

Also I currently use Delos eyepieces but I guess they will be too heavy for binoviewers?

On the actual binoviewers I have a budget of up to £2000, but is the Baader mark V really that much better than the Baader maxbrights?

Also I'm confused about the barlows I may need and whether I will be able to use a 2" diagonal rather than 1.25"?

Gavin

[GavStar]

I was considering the WO binos as a good value entry to binoviewers but was concerned about having to use a 1.25" diagonal to get into focus which would result in quite a load on this smaller diagonal

[Space Dragon]

Gavin

Your ED120 would be good for binos and high mags would be no problem with any sort of binoviewer, the hard bit is getting low powered, wide field views out of a bino.

By adding the extra length of the bino and pushing the focal point back you are adding magnification and constricting the FOV.

The Baader T2 system goes a long way to overcoming this in that the T2 prism diagonal has a light path of 38mm and the bino body screws directly onto the prism via a T2 thread, getting rid of the nosepiece of a diagonal.

This gives you the shortest light path and it also decreases the weight and moment arm on the refractors focuser and makes the whole set up much more user friendly.

The main difference between the MK V and the Maxbright is the size of the clear aperture, the MB is 21mm at the EP side, the MKV is 30mm, so there are no 1.25" EPs that will vignette in the MK V but with the MB 25mm plossls are the widest you can go without vignetting.

The prisms are meant to have about 10% more throughput but in reality people that have both don't seem to see a big difference.

The self centring diopters on the MKV are precise but the compression rings on the MB are also very useable.

The new Denkmeier Binotron is a great bino and worth a look.

But initially it might be a good idea to buy a WO to see if you get on with it, if you do you'll resell it quickly and then think about an upgrade.

You can't use the WO with the Baader T2 system though, only a 1.25 diagonal,or a 2" with 1.25 adaptor, it'll still work well enough though.

The Baader system also uses GPCs [glass path compensators] which are barlows that sit in the prism diagonal. x1.25/x1.7 and x2.6.

These will help you reach focus in a refractor, usually the x1.25 is enough, if you can't reach focus native.

I ended up taking the power switch off my Earthwin bino, getting a custom adaptor made to fit the bino directly onto the T2 prism, same as the MKV/MB and I can reach focus with an F/5.9 with a few mm to spare......with no barlow or GPC......this is what gives the wide FOV.

The other option is to cut the tube...which I've done with cheaper scopes.

 The method to find how much back-focus your system has and what you may or may not need in the way of GPC is on the Maxbright page...

http://www.alpineastro.com/Binoviewers/Maxbright%20Binoviewer%20Instructions.pdf

If you were to spend over £1000 on a bino then either the MKV or the Binotron would be the way to go.

I have seen photos of Delos 17mm in binos and lots people use Nags and Ethos, although for me 68º is enough in binos as you can't really turn both eyes around the edges of the FOV as you can do mono, it tends to just black out.

The WO is also around 20mm aperture so you will be limited in the EPs you could use without vignetting or illumunation fall off but you will get a feel for binoviewing and the image will be good.

The WO comes with a 1.25" nosepiece and a barlow x1.6 i think, so it's plug and play really.

Many people do have a binoviewer for high mag and a binocular for wide field, it's really what each do best.

I wish I had £2000 spare to spend on a binoviewer....:-)

[Mark in Macc]

I wish I had £2000 to spend on binoviewers as well I could flex the plastic but would be in the divorce court later that day. My understanding is that Denkmeier and Earthwin make the best of the binoveiwers. The Baader mk V are also supposed to be good and I suspect that the TV offerring is no slouch either. Some people just don't get on with binoviewers or binoculars for that matter. I would certainly try before you buy, or buy at the cheaper end and see how you get on. I use my binoviewers with a standard 2" diagonal and have permanently attached a 2" adapter to the nosepiece, which makes them really secure when attached. The WO binos do come with a 1.6x Barlow, but I prefer pairs of EPs. If you like them, you will not go back to singles again, especially for lunar and planetary observing where time at the eyepiece is the most important benefit. Eyepiece choice is one thing to be aware of though. Some eyepieces will be too wide to get your conk in between. Again, try before you buy. I suspect that Delos may be too wide, I`m not sure.

[GavStar]

Mark,

After your comments, I am thinking at staying at the cheaper end for now rather than flexing the plastic! I like the sound of the Baader maxbrights with the T2 diagonal.

I think I saw that you bought Vixen NLVs for use in your binoviewers - how did these work? They have a nice 20mm of eyerelief?

Gavin

[Mark in Macc]

Hi Gavin, you are very wise to do your homework and possibly buy at the cheaper end to start with. I have been lucky in that the WO binos I have are on semi-permanent loan from my astro society as no one else seems interested in them. I have been able to play around and figure out what works and what doesn't. A friend of mine tried them out a few months ago and was nearly sick! Some people end up seeing 2 images and their eyes cannot combine these. What I found was that I need to get both sides focussed properly (they have dioptres on each side) and get the inter-ocular distance correct, otherwise the 2 images don't 'snap' together. When this does happen, however, you enter a different world! The first time I looked at the moon through binos was a serious 'wow' moment. Optically, the WO and Baader Maxbright offerings are very similar. There was a group test in Sky at Night magazine a few years ago and the WO binos came out on top, beating the Maxbrights slightly. If you pm your e-mail address I will send you the pdf. The reviewers were seriously impressed by the WOs for the money. I did read that a lot of these so-called "Chino-viewers" use optical components from the same Chinese factory. The casings and fittings are different. If you can use a 2" diagonal, then the WO binos don't need anything extra. I have converted the nosepiece on mine to a 2" fitting and they are solid as a rock with this combination. Binoviewers do tend to be fairly heavy, the WOs weight about 700g and require a secure fitting. If you do need to use a 1.25" diagonal, then the Maxbrights are probably the best option as you can screw them straight into the diagonal body, which will secure them nicely and will reduce the light path, which can be a problem with certain types of OTA due to focus problems. It is worth checking, though, whether you can easily rotate the binos once attached through this system as there may be times that you need to do this to get into a more comfortable observing position. This is especially true when using a SCT with an equatorial mount.

In terms of eyepieces, both the WO and Maxbright binos have a field stop of approx. 21mm. If you choose EPs with larger field stops, you will get vignetting. 25 mm TV plossls are excellent and have a field stop of 21mm. The 20 mm SWAN eyepieces that come with the WO binos are also surprisingly good. Both of these options have soft rubber eyecups, a large eye lens and are fairly thin so that they don't feel too crowded around the bridge of your nose. Be very careful about the width of any eyepieces that you buy. Other options that should be fine are 19 mm Panoptics, BST Explorers, orthos etc. The jury is still out with the NLVs. Optically, they are top-notch, but the twist up eyecup is quite wide and they don't feel as comfortable as the others. I've only used them twice and I suspect I need a good 2 hour lunar observing session to make my mind up. I think I generally prefer soft rubber cups on my eyepieces. I wouldn't rush out to buy NLVs for binoviewers, try before you buy to make sure you can get your nose between them and feel comfortable. A trip to your local, friendly astro-dealer would be very useful. Vixen have apparently re-designed the body again, but I don't know if they are any narrower. The current NLVs have a slightly plastic feel to them.

As you can see, it's a minefield. The hardest choices I have had to make since taking up the hobby are the eyepieces for my binos!

[GavStar]

Mark, Thanks, I have sent you a pm. Interesting to hear that the NLVs are maybe not the best option. I note that you often use the binoviewers on the moon ("wow" factor), I'm keen on the planets more - is there less "wow" on these? My local astro shop did infer that this was the case...

[Mark in Macc]

Hi Gavin, I wouldn't discount the NLVs. I think you would need to test a pair out for comfort. They may be fine, I just need a bit more time with them. The comment about the moon stems from the fact that it is much more accessible on a regular basis than the planets and I have grown to love observing it, mainly due to the binoviewers. The best view I ever had of Jupiter was with the 20mm EPs that came with the binoviewers. You do get a 3D perspective, which is rather wonderful. It's more down to the opportunities that you get for 'wow' moments. I'm hoping for a few more with the planets in due course.

[GavStar]

I thought I would post an update on this topic. I did get the WO binoviewers but didn't get on with them. So after reflecting on this I've decided to have another go with a better spec system - see the attached photo. I hope this gives views I like.