558 replies to this topic

[Tamiji Homma]

I went out to look at Big Dipper with Vixen SG 2.1x42.
In terms of FOV, the chart below is very close to what I saw.

The red circle is FOV 30 degree. 7 stars are well within FOV.


Tammy

[Tamiji Homma]

It was exactly 32920 JPY, or around $323 USD. The only fee incurred was the one Wells Fargo charged to wire the money, which was more than I had expected, but as I was already sitting there in the banker's office, I couldn't let that be the deal-breaker.... It came out to total about $370... YOLO

I bought mine using Amazon Japan. It was 25,200 yen including S&H. They didn't ship directly to the U.S. address so I shipped to my sister there.

Well, I emailed her that binoculars were coming but she didn't read email for weeks. She returned the pacage to seller

Then she realized that I bought it and sent it to her in another week... The seller sent it back to my sister and then she sent it via EMS to the U.S. EMS cost 2,420 yen. So total in US dollar, is about $272.

My sister S&H ends up costing whole a lot more than $272 later...

Tammy

[ianatcn]

Here are some pics to show the different attributes of the Widebino28 and the Vixen SG:

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[ianatcn]

This one shows the difference in the eyeguards. note how narrow the Widebino is compared to the Vixen:

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[ianatcn]

A nice attribute of the Vixen is the tripod adaptor. Why on a 2x binocular? How about attaching it to one of the night vision head mounts for hands free observing?

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[ianatcn]

The relative size of the binoculars is primarily due to the over-engineered luxury machining of the Vixen:

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[ianatcn]

So, if the Vixen is one up with the tripod adaptor then the Widebino evens the score with the optional 2" filter adaptors:

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[ianatcn]

Coatings and internal baffles in the Vixen are first class:

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[ianatcn]

Although the Widebino is good.... no cigar:

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[ianatcn]

Similar cases, the Vixen though is padded:

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[ianatcn]

Here is the product label on the Vixen box, should you wish to order :

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[ianatcn]

Ian,
My Russian unit does indeed have 'frosting' on the eyepjeces.This is a fairly wide, ground conical taper on the edge, which restricts the diameter of the rearmost surface. I presume this was done as a means to aid eye centration. I'd not call it a baffle of any sort, for it does scatter light rather obnoxiously. I painted these conical, ground surfaces black, which very greatly improved things.

The rear, black, perforated caps simply unscrewed. But these also retain the knurled sleeves, which easily fall off now. I placed small strips of masking tape on the inside walls of these sleeves so as to somewhat fill the gaps between them and the eyepiece barrels. This holds the sleeves in place via friction, but with sufficient freedom to turn for focusing.

Interesting that Vixen states a mere 12 degree FOV, while the full Dipper fits within, confirming at least a 25 degree FOV.

Regarding magnitude gain, this is easily calculated. We will initially assume virtually 100% transmission efficiency. And that the bino always operates at the user's pupil diameter, we know sky brightness remains the same, and hence the brightness gain on point sources scales as the square of the magnification.

At 2.1X, the areal increase on the entrance pupil is 2.1^2 = 4.41. The magnitude equivalent is LOG(4.41) * 2.5 = 1.61.

We might subtract at most 0.1m, to account for transmission loss.

Note that for users who are rather farsighted or nearsighted, the eyepieces at infinity focus will be located farther from or nearer to the objectives, respectively. This will result in a respective slight increase or decrease in magnification.

Thanks Glenn, the change in magnification is most apparent when focusing from far to near objects during the day.

I am encouraged by your description to have a go and modify the eyecups of my Russian glass and blacken the lens edges. If that works then I may try the same on the Widebino and keep them for use with filters. The Russian model can then find a home with one of my astro friends. The Russian model can be purchased used quite cheaply, mine cost around $20 equivalent. I will take some pictures while I modify it just in case someone else wants to go this route.

Tammi has illustrated exactly what I was experiencing with field of view, suggesting that the 12 degree stated by Vixen must be a misprint.

[Tamiji Homma]

Tammi has illustrated exactly what I was experiencing with field of view, suggesting that the 12 degree stated by Vixen must be a misprint.

Hi Ian,

Vixen Japan web site has following description:

They use "eye relief" and "eye point" interchangeably.

Eye relief at 8.4mm: TFOV 12.2 degree, AFOV 25.2 degree
Eye relief at 5.6mm: TFOV 13.6 degree, AFOV 28 degree

I guess language mixup or something? Or it is difficult to apply regular AFOV/eye relief concept in Galilean optical system.

The chart I posted is when I was really close to eyepiece, pretty much touching eye lens. In other words, I tried to get wide field as much as I could.

Tammy

[GlennLeDrew]

Ian,
The eyepiece end caps on my USSR unit were locked in place with a bit of cement, it seemed, as it required some force to get them loosened. Who knows if the same procedure was adopted by the new maker... Don't give up too soon if they seem really tight. See what avails with all force shy of causing damage to the caps. I had to use a large Vice Grip, which marred the outer rim of the (long since discarded) end caps. If you're confident of not wanting to reinstall the caps at any later time, then have at 'er, scrapes be darned! Just be careful to gently (but firmly) grip the focusing ring around its full circumference.

[Patrik Iver]

I'm tempted, but the one thing all eyepieces and binoculars I've bought and later kind of regretted buying, have one thing in common:
Short eye relief...

So I really should not even think about these...

[ianatcn]

I'm tempted, but the one thing all eyepieces and binoculars I've bought and later kind of regretted buying, have one thing in common:
Short eye relief...


So I really should not even think about these...

Whilst I would agree with the Widebino not being suitable for someone with an aversion to short eye relief the Vixen is different. On paper the eye relief may be short but the ergonomics of the eyecup and viewing comfort result in it feeling quite comfortable. However, if you wear glasses when observing then it will be impossible to enjoy the panoramic field.

[Patrik Iver]

I'm tempted, but the one thing all eyepieces and binoculars I've bought and later kind of regretted buying, have one thing in common:
Short eye relief...


So I really should not even think about these...

Whilst I would agree with the Widebino not being suitable for someone with an aversion to short eye relief the Vixen is different. On paper the eye relief may be short but the ergonomics of the eyecup and viewing comfort result in it feeling quite comfortable. However, if you wear glasses when observing then it will be impossible to enjoy the panoramic field.

I do (need to) wear glasses while observing. I've tried contact lenses, but that was maybe 20 years ago - perhaps I sould try again?

[Rich V.]

I've been wearing RGP contacts for nearly 50 years now; I can't imagine doing without them. They're sure a big help for astronomy, IMO.

Rich

[SMark]

I've tried contacts twice and failed both times. Apparently my eyes only produce a fraction of the tears they are supposed to. Outdoors in humid conditions I could just tolerate wearing contacts. But the minute I went inside where it was air conditioned everything quickly dried-up and became painful.

My astigmatism is gradually getting worse, but I can still use all but my 7mm exit pupil binoculars without my glasses, just correcting my near-sightedness with the focus. I'm not sure if I could use this Vixen Widefield or not...

[genethethird]

I need a nightvision harness too, but the issue I think is getting the Vixens close enough to the eyes. Is this an issue with most available harnesses, i.e. are they fully adjustable to the point where one could get the binoculars aligned closely enough with the eyes?

This one looks to be the ticket- third picture down. Anyone have one of these, or even know what the product is called?

buy it here!

[JustaBoy]

Wow! - Now that is cool!

Even blocks out all the light except for that coming from the Bins!


Thing is - Better take them off if you have to do much moving around:-)

[osbourne one-nil]

Had my first proper use of them last night (I had taken them to Ullswater on Thursday evening) and although the sky doesn't get very dark here at this time of year, the views are so, so pretty. Cassiopeia, for example, fits really nicely in the field of view, and compared to the naked eye extra stars just pop into view. The same went for Lyra and The Plough. It's just fun scanning about with them, and at only x2 magnification, holding them rock steady is a given.

The only disappointing factor (and I suspected this would be the case) is that the stars are only sharp in the central field of view. After years of using Televue eyepieces, this is going to take some getting used to. I noticed slight changes in focus and inter-pupil distance made quite a difference, but stars were certainly never sharp to the edge. I guess this goes with the optical design?

These will make lying on the ground and staring up very appealing, other than last night when the midges were out in force.

[ianatcn]

Glad to hear your SG has received it's first starlight. I think everyone who buys one of these should christen them on cassiopeia. Because the starfield around the constellation is rich and the W asterism is nicely framed the great attributes of this glass really stand out.

A bit more use and trying to avoid the TeleVue habit of rolling your eyes around the fov, moving the binocular instead and you will find you hardly notice the peripheral aberrations.

The midges? No advice I Can give there, sorry.

[GlennLeDrew]

If one swivels one's eyes so as to gaze askance toward the field edge, it's to be expected that aberrations will become more visible. And more importantly, additional aberrations are virtually certain to result.

Instead, gaze only toward the field center, letting peripheral vision utilize the outer field. The view overall will be better for it.

[smart]

How does the Vixen 2.1x42 compare to the Sard 6x42 porro prism binocular in actual views-anybody tried?