Vixen SSW 83° eyepieces

[Wavytone]

DSomeone suggested vixen copied Nagler. I doubt it - the idea of the Smythe lens predates both - which both Nagler and Vixen used (as well as ES, Pentax and Nikon not to mention Baader and the cheap Chinese clones). The Smythe lens idea is the basis of every UWA eyepiece design.

The other point is the LVW set spanned the range from 3.5mm which is as about as short as anyone could usefully want, right up to one that has a field stop as large as can be squeezed into a 2" barrel (the 42mm) - and all can be used with a 2" focusser and weigh close enough that there's no balancing needed. There still isn't another set that does this.

And as for focal lengths Vixen made the largest range of focal lengths bar none in the LV range (ceased manufacture years ago). Something for every one there - 2.5 - 50mm.

As for the SSW... an 82 degree field in a 2" barrel works out at roughly 30mm focal length, and between that and 14 mm there's a factor of two, so slotting one in at 21 mm would make a decent set.

The only snag is the SSW's are small and don't have a dual 2" barrel which rather suggests Vixen won't make a 21 or 30, or if they do they'll be oddballs. Pity.

TV created the same problem in that to span this range you need a clutch of Naglers and a couple of Panoptics.

[PlanetMan]

I think the exact word was "follow" not 'copied' as you stated. Given that the existence of the Naglers came first and both brands employ an optical design that neither manufacturer actually invented then I think the earlier comment is correct.

Please don't misunderstand me - I personally think there is a lot of hype with Televue Eyepieces and many other brands are just as good or better but at half the price - Vixen is a perfect example of this so I am glad they are making these eyepieces and the reference to Nagler is merely a way of recognising this new range of Vixen EP is a 80+ afov

[Don Pensack]

I will be testing these in the coming days, though we have 10 days of clouds predicted.
I'm looking for lateral color (prism or CA), astigmatism, brightness (transmission), comfort in use (adjustable eyecup looks promising), coloration of the image, flatness of field, suitability for short focal ratios, etc.
Will they work well in short dobs? The jury is still out.

[MortonH]

The new Vixens are listed as in stock by some vendors in the US. RRP (US$) is $490 but actual price is $349 (versus $310 for a Nagler Type 6).

http://www.vixenoptics.com/category-s/161.htm


No first light reviews yet. Don, how's your weather?

[Don Pensack]

I want to test these and do a write-up but we are having typical weather for SoCal every day:
low clouds and fog until 2pm, then clearing to sunny blue skies. Clouds and fog roll back in right around sunset and we're cloudy until 2pm the next day.
I have had zero clear nights here since a month ago.
I want to test the new TeleVue DeLites and these new Vixen SSWs, but, for some reason, I can't find my cloud filter. :-(

[MortonH]

I asked MyAstroShop about availability of the SSW.

They said hopefully within 4 weeks with their next shipment from Japan.

Based on the current exchange rate, expected price is around $400.

If $400 is right, that would make them about 10% cheaper than a new Nagler T6 here, so will be very interesting to see how they compare.

[MortonH]

Don Pensack has posted his first light comparison with Nagler T6's and DeLites. The Vixens came last.

http://www.cloudynights.com/topic/50...nd-vixen-ssws/

[mental4astro (Alexander)]

By the sounds of the aberrations Don had noted, these Vixen EPs are not for Newtonians. But nobody on CN seems to notice that the review was only done with a Newt, and not a refractor, SCT or Mak.

[MortonH]

Originally Posted by mental4astro

By the sounds of the aberrations Don had noted, these Vixen EPs are not for Newtonians. But nobody on CN seems to notice that the review was only done with a Newt, and not a refractor, SCT or Mak.

Don did say he's going to test them in his 4" f/7 apo to see if they perform better.

He also points out that they're not BAD eyepieces, just not quite as good as the Nagler T6's (despite being more expensive in the US).

[AG Hybrid (Adrian)]

He was even using a coma corrector too. Maybe they are good in SCT's?

[mental4astro (Alexander)]

Morton you are right. My freaking phone gave me trouble when editing my post, and I have not had access to a machine to change my original post.

Yes, the comment of Don's is that these EP's work well in a refractor. But this is as a small comment on the side, not in the major review. This is where most of the bad press will come towards these eyepieces.

The point is that these eyepieces are focal plane specific. It does not mean there is anything wrong with them. It just means they are not suited to Newtonians, which is not the largest market for telescopes in Japan who prefer Cats and refractors - which these eyepieces appear to be matched to, as you suggest Adrian. As such I do not have a problem with this. I understand the matching of scope and eyepiece optics. But many people do not. I have several eyepieces that are scope specific, and I do not interchange them from scope design to the other as I know they will not 'work'. But put in the right scope and they are a ripper.

[Wavytone]

Alex the eyepiece reviews on cloudynights are also dominated by short dob users. Anyone else might as well not exist as far as they're concerned. I think you know this, and where Don Pensack fits in that community.

I'm only interested to see if anyone puts these and a few others on an optical bench and makes some objective quantitative measurements. So far no-one has.

Once again the issue of choosing the right eyepiece to match the aberrations of the scope arises, but Don won't admit as much.

Anyway the quality of most threads on cloudynights seems to have declined badly lately.

[WilliamPaolini]

Originally Posted by mental4astro

I have several eyepieces that are scope specific, and I do not interchange them from scope design to the other as I know they will not 'work'. But put in the right scope and they are a ripper.

I wish more folks understood this better. I am so tired of hearing that an eyepiece is fundamentally "bad". Most of the time they are judged "bad" because they were used improperly, outside their operating parameters. As example, do not expect a 3 element design to perform so hot in an f/4 scope. Just not going to happen. But put it in an f/8 scope and like you said, can be "ripper"

[Don Pensack]

Well, I did get a chance to use them here at home in my 4" f/7 triplet apo refractor (714mm focal length).

Some notes:
The only aberrations noted were some astigmatism at the edge (and it was just a *trace* better than in the coma-corrected dob), and the same exit pupil issues I noted in the dob.
All other characteristics were not noted in the somewhat brighter skies of my home. Edge reflections, field stop focus, lateral chromatic issues all went without notice.
I intend to use these again in the refractor at a dark site so I can evaluate the other issues I saw in the newtonian.
I don't have an f/10 or longer scope to test these in, but they likely would perform better in regards to edge of field astigmatism in the longer f/ratios.
These likely would be excellent in long f/ratio refractors and Maks.
I am concerned with the exit pupil issues, though. There are some issues with acquiring and holding the field when using these.
To put that in perspective, it is nowhere near the problem of using the original Naglers, which had kidney bean blackouts dues to spherical aberration of the exit pupil. I think you would only notice it in the Vixens if switching to another eyepiece that had no such issue.
Given the refractor has close to 1/3 the focal length of the newtonian, I was surprised to not notice any notable field curvature.
I'll post more when I get a chance to use them at my dark site, which is at least 4 magnitudes darker than my home.

[MortonH]

MyAstroshop is now showing prices for these, suggesting they may be in stock.

Unfortunately the price is rather high at $465