[Sancho]

If anyone is looking for a Swarovski Eyepiece Adapter to fit a 1.25'' inch astro eyepiece, it seems they've been unavailable for years. But here's a way to make one's own, if you have the tools and the know-how:
http://www.valeasy.fr/accueil/fiche_...2ad822ddf3ad60

It's beyond my scant capabilities, though.

[DRodrigues]

Sancho,
You missed the fact that you can purchase it http://www.valeasy.fr/accueil/fiche_...&marque=#tabs1

Good news for Swarovski owners!

[Sancho]

Originally Posted by DRodrigues

Sancho,
You missed the fact that you can purchase it http://www.valeasy.fr/accueil/fiche_...&marque=#tabs1

Good news for Swarovski owners!

Thanks, DRodrigues! I should have paid more attention in French class.
I've just ordered one, and will report!

[Sancho]

The copy of the Swarovski Astro Adapter arrived today. It's a perfect fit, and was hand-tooled rather than simply done on a computer metal-tooling thingy. Unfortunately the only astro-eyepieces I have are fairly lousy quality - they came with a fairly cheap "ball-end" portable astro-scope I got for my son. I tried an 8mm and the magnification was huge, but it was far too dark for non-astro use. I'll research better eyepieces, with lower mag, and report.

Edit - I'm not sure the eyepiece I tried is really 8mm, because it gave far higher magnification than the zoom at 50x. I reckon it was about 80x, just guessing. On the eyepiece it says "H8mm". I know nothing about astro-eyepieces, though, so I'll have to go to the Astronomy Ireland shop and try a few.

[Hermann]

Originally Posted by Sancho

Edit - I'm not sure the eyepiece I tried is really 8mm, because it gave far higher magnification than the zoom at 50x. I reckon it was about 80x, just guessing. On the eyepiece it says "H8mm". I know nothing about astro-eyepieces, though, so I'll have to go to the Astronomy Ireland shop and try a few.

Sounds like a Huygens eyepiece, invented by Christian Huygens about 350 years ago. Such eyepieces work reasonably well at long focal lengths, at short focal lengths they suffer from short eye relief, a very narrow AFOV and generally a pretty lousy image quality. Very inexpensive to make, still sold with many cheap telescopes.

Try to have a look at some decent eyepieces. With an 80 mm scope I'd aim at something like 80x-90x magnification, so I'd look at 5mm and 6mm eyepieces.

Hermann

[Sancho]

Originally Posted by Hermann

Sounds like a Huygens eyepiece, invented by Christian Huygens about 350 years ago. Such eyepieces work reasonably well at long focal lengths, at short focal lengths they suffer from short eye relief, a very narrow AFOV and generally a pretty lousy image quality. Very inexpensive to make, still sold with many cheap telescopes.

Try to have a look at some decent eyepieces. With an 80 mm scope I'd aim at something like 80x-90x magnification, so I'd look at 5mm and 6mm eyepieces.

Hermann

Thank you Hermann! The view through the H8mm was so bad I think it was one of Huygens´ originals, that had been left in a mouldy attic since the 17th century.
Val´Easy (the company in France that sent me the astro-adapter) have also sent me a list of eyepieces that should work well with the Swarovski scope. (They are most helpful and accommodating, and very enthusiastic about their work and products. The adapter is a marvel to look at - I´m not very technical, but it´s quite beautifully made!) They recommend, for example, Takahashi 5 or 7.5mm for daytime use.

[John Russell]

Sancho,

I will continue on your thread. I had opened a new one merely to draw attention to the availability of the Jülich adapter.

If it's any consolation, you are not the only one to jump the gun. I had just about given up hope of the Jülich adapter becoming available and had a few days previously sold my 9 mm Vixen LV. I think it would have worked quite well on my ATM 65HD at 51x.

Yesterday I took delivery of a 6 mm William SPL but, unfortunately, it doesn't achieve infinity focus and I will have to return it. The reason is the 30 mm barrel, which forces it to protrude 8 mm out of the adapter. The contrast too leaves something to be desired at 77x and only 0,85 mm exit pupil in the 65 mm scope. Ideally eyepiece barrel length should not exceed 22 mm (0,9") and this is shown as dimension "B" on the specifications on the Televue web site: http://www.televue.com/engine/TV3_page.asp?id=28. The Plössls and two Panoptics fulfil this requirement but are not really what we are looking for. I do have an 11 mm TV Plössl, which has very good contrast, but the eye relief is poor and it is worse on the 8 mm.

No doubt you have now acquainted yourself with the price of the Takahashi eyepieces :-(. They are probably excellent for planetary viewing in top quality astronomical Apo´s but there are hopefully more suitable and affordable solutions for Swaro scopes. Did Val´Easy have any further recommendations? I believe the Vixen NLVs (successor to LV with twist-up eyecup) would offer a comfortable view but below 9 mm they only have 45° AFOV.

John

[Sancho]

Hi John! Many thanks for that info. The gentleman at Val'Easy in France has a Swaro ATS80HD too, and as well as the two Takahashi eyepieces he mentions, also uses a Televue Apo 85, sometimes with a binoviewer, for daytime viewing. I'm not acquainted with astro eyepieces (apart from the excellent Baader Zoom which I used on a Zeiss 85 TFL), so I'm on a learning curve here. Val'Easy's main line is custom-built, lined protective carry-cases for scopes, etc.

[FrankD]

If I may offer a suggestion with affordable astro eyepieces? I have been tinkering with a few in the scopes I have on hand. I have some others coming to try out.

I continue to be impressed with the performance of the Celestron X-cel XL that I recently had modified to achieve infinity focus in the Theron Mag82 scope. The image is exceptionally sharp, bright, CA-free and with very good edge performance. Granted it is a 25 mm version (only about 20x in the scope) but I am eager to try something in the 8-10 mm to see how it performs. For only about $65 US they seem like a likely choice for folks looking to experiment with a spotting scope. I believe they all have a 60 degree field of view and 16 mm of eye relief. I believe they use ED glass in their design (their predecessor the X-cels did) though I don't see it listed in the description anywhere.

Just a suggestion.

http://www.adorama.com/CN25XCLX.html

[DRodrigues]

Sancho,
Since you are used to wide angled eyepieces you should purchase one with at least 60º AFOV (otherwise you will feel to look through a small hole...). The suggestions I gave you on the last reply to your post http://www.birdforum.net/showthread.php?t=192910&page=3 was considering that I think you use eyeglasses. The 80-82º AFOV eyepieces usually have only 12mm eye-relief which don't allow eye-glasses users to see all field, in fact a XW 70º AFOV (20mm eye-relief), have bigger useful field than a equal magnification 82º eyepiece - that's one of the the reasons why I use a XW5!
For non users of eye-glasses the 80-82º eyepieces might be interesting.
For birding the ES 82 eyepieces might be a good solution since have a bit better eye-relief (14...), are weather proof and not much expensive - in your magnification range I would recommend the 6.7mm model e.g. http://www.apm-telescopes.de/eyepiec...nfo_38234.html
The suggestion I gave before on the TS 60º eyepieces seem to be the inspiration of the Celestron that FrankD mentioned and are the ones more available in Europe.
By the way the Delos still aren't available - they will start to ship soon.
I didn't recommend you a XW since there isn't a 6mm model. However if you will decide by a 7mm, I strongly recommend it.

[Sancho]

Thanks for the excellent suggestion, Frank! (You pointed me in the direction of the Baader Zoom which was also excellent advice).
I've had a look at the other Celestron X-Cel LX eyepieces from Adorama, and I have a really amateurish question. I believe the focal length of the Swaro ATS80HD scope to be 460mm. Does this mean that the Celestron X-Cel LX 5mm ep will give 92x magnification, and the 7mm will give 65.7x magnification? If so, these two could be just what I'm looking for.

Thanks David for the advice too, if these are more readily available in Europe I'll check them out too.

Edit - many thanks to all for advice. I've taken David's suggestion and ordered the 6.7mm eyepiece from the German website ("APM Telescopes" - it claims 82 degrees AFOV!). It's hit-and-miss as one is choosing rather "blindly", not having a chance to test. (I couldn't find anywhere even in the UK that will ship the Celestron X-Cel LX to Ireland). I'll report as soon as the German eyepiece arrives.

Edit and correction - Rother Valley Optics will ship to Ireland. In a few weeks, I might just order the 5mm Celestron X-Cel LX for giggles, as it's fairly inexpensive.

[John Russell]

Sancho,

Do bear in mind that Pentax and Celestron scopes are designed to accommodate astronomical eyepieces but that the Swaro scope plus adapter will only accept 22 mm barrel length. Anything more is going to use up some focus overtravel and may, as in the case of the William eyepiece, prevent one achieving infinity focus. Some do machine a few millimeters off the end of the barrel for use on Zeiss or Swaro scopes but I wouldn't want to try it.

From illustrations of eyepieces it's difficult to judge the length (set in relation to 31,8 mm diameter) but that Explore Scientific 6,7 mm does look suspiciously long. I hope it works!

Telescope Service agreed to exchange the William eyepiece and, due to a lack of safe alternatives between 6 mm and 8 mm, I have ordered a 6 mm Vixen NLV. They took an 8 mm Vixen LVW out of the stores and measured the barrel length at 25 mm so that would probably work and I will keep that in mind as a future option. It has received excellent reviews (http://www.vixenoptics.com/PDF/lvw_review.pdf) but is rather expensive and has the weight and dimensions of a soup can!

John

PS: Your magnification calculations are correct.

[FrankD]

John,

Thanks for answering Sancho. I didn't check this post out until now.

I do have to admit that I have eyed up the Vixen Lanthanum NLVs for some time now. I am sure they are excellent eyepieces. I am having a bit of a hard time justifying the cost on my end when I can find other astro ED eyepieces at less expensive prices though. Let me know how it works out for you. I am considering a more magnification in a fixed power ED eyepiece and may still consider the Vixen's if they work out on your end.

[Sancho]

Thanks John and Frank! The German eyepiece hasn't arrived yet, but I've found a dealer in the UK (Green Witch) that has the Vixen NLV Lanthanum for about 140 quid sterling. So if the German one doesn't work, I can get either the Celestron L-XCel or the Vixen NLV. Although I'm not awash with cash, the prices of these "top-end" astro eyepieces don't seem excessive when compared with the prices of regular eyepieces for good (daytime use) spotting scopes. The Celestron L-XCel costs 71 quid sterling. Not sure of the barrel length, though.

[DRodrigues]

Originally Posted by John Russell

Swaro scope plus adapter will only accept 22 mm barrel length. Anything more is going to use up some focus overtravel and may, as in the case of the William eyepiece, prevent one achieving infinity focus.

John that's might be true for plossel eyepieces but not for wide angled i.e. more complex eyepieces have lens near the end of the barrel so what would be determinant is the distance from these lens until the end of the barrel, besides the eyepiece optical design.
Regarding safe alternatives, from the 5mm test http://www.pt-ducks.com/cr-telescope...mm%20eyepieces I have the idea that the TS HR model was the one that needed less focus travel so if the TV focus on the Swaro the HR should also focus. The TS Expanse models seem to be good but only have 8mm model http://www.teleskop-express.de/shop/...otothread.html and don't know about the focus point - you could ask TS about it.

Sancho,
There are coincidences and 2 days ago I passed through my friend to see if the ES100 models have better useful eye-relief than the TMB100 (for eye-glass users...), and it had also a ES82 6.7mm... I tested it on the Optolyth 100 and it focused! It seemed a nice eyepiece but I didn't had much time to test it. Noticed that it's not a eyepiece for eye-glass users but for other users might be good. After testing it, let us know what you think about it...

[Sancho]

Originally Posted by DRodrigues

Sancho,

After testing it, let us know what you think about it...

Of course I will, David! I wear eye-glasses, but they sit very close to my eyes so I don't need much eye-relief, 11mm or so. I can also view without them as the prescription isn't very strong. I'll post my findings as soon as the eyepiece arrives, and if the barrel is too long, well, God made hacksaws so that long pieces of metal could be shortened...

[John Russell]

David, I realize that the optical design plays an important role but a significant difference between the Swaro scopes and astronomical scopes, apart from the amount of focus travel, is that an eyepiece will seat at the base of the barrel in an astronomical scope and at the tip of a long barrel in the Swaro.

If a 19 mm TV Panoptic with 0,9" barrel and 14 mm TV Radian with 1,4" barrel were parfocal in an astronomical scope, the Radian still might not achieve infinity focus in a Swaro.

It may be coincidence but those TS Expanse eyepieces are available in the same focal lengths, i.e. 3,5, 5, 8, 13, 17 and 22 mm as the Vixen LVWs. They are also similarly heavy but much more reasonably priced - Chinese clones perhaps?

BTW, there are a number of eyepieces under different names similar to the William SPLs, Astro Professional LEs for instance, so these are to be avoided for use in Swaro scopes.

Anyway, experimenting is fun and maybe Benm, Sancho and I can help others to avoid the pitfalls.

John

[Sancho]

Originally Posted by John Russell

Anyway, experimenting is fun and maybe Benm, Sancho and I can help others to avoid the pitfalls.

John

True - the wise man learns from the mistakes of others, the fool from his own.

[John Russell]

The replacement for the William SPL, a 6 mm Vixen NLV arrived yesterday. Unfortunately 95% cloud cover prevented any tests on the stars and Saturn but I was able to do a few terrestrial checks.

The eyepiece is AFAIK optically identical to its predecessor, the LV, i.e. a super Plössl (a biconvex lens in between two doublets) with a doublet Barlow as a field lens. It is now 50% more expensive than the old LV and the fold-down rubber eyecup has been replaced by a twist-up eyecup with click stops at both extremes of its 10 mm movement. Though black-outs are no great problem, I would have preferred another 1 or 2 mm extension.

The chrome plated barrel is internally blackened and is just 22 mm long so that the eyepiece seats on the Swaro adapter flange. The mechanical execution is acceptable but not up to Televue, let alone Swarovski standards.

The combination is essentially the old Swarovski 77x eyepiece (rebadged LV on the original Swaro astro adapter) but it nevertheless came as a surprise to find that it is, to all intents and purposes, parfocal with the Swaro 30xW eyepiece. Needless to say, a small adjustment of focus is usually required at the higher magnification.

AFOV is a mere 45° but viewing with or without glasses is quite comfortable with the minor reservation mentioned earlier, that I would prefer a little more eyecup extension with the 20 mm of eyerelief.

There is some pincussion distortion, which I do not recall seeing on a 9 mm LV I previously owned, but I could not see any astigmatism and there were very slight amounts of field curvature and lateral CA.

There was naturally some loss of contrast in my ATM 65HD with an exit pupil of only 0,85 mm but it was surprising how well the little scope held up at 77x and I am looking forward to views of the sun (with Baader filter foil), moon and planets. The gains in intelligibility as against the 30xW were subjectively better than I had noted with a doubler on binoculars. Perhaps too the eyepiece will help with the odd long distance wader ID across water.

After a false start, eyepiece and adapter can be considered a worthwhile addition.

John

[Sancho]

Excellent, John. I'm glad it's a useful addition to your kit. My German eyepiece hasn't arrived yet, I'll report as soon as I get it.

[Sancho]

Update - I've used these today, and can report that the Explore Scientific 6.7mm does reach infinity focus using the excellent Val'Easy astro adapter.
The ep doesn't look pretty (see photo), but it does the job. Pretty sharp and reasonable FOV for a 68x mag, but obviously darker than the Swarovski 25-50 ep that I normally use. It shows a lot of "pincushion", which doesn't really matter as I'll only be using it very occasionally in good light for getting a closer look at very distant stationary birds. All in all, a pretty good solution to the high-mag dilemma. The Explore Scientific ep (bought from APM Telescopes in Germany) is made in China, and bears the legend "6.7, 82 degrees series, Fully Multi-Coated, Nitrogen Purged, Waterproof".
I'd be interested later in getting one of the Celestron L XCel 7mm ep's, for the sake of comparison.

[dipped]

That's a nice picture of the garden!

[Sancho]

Originally Posted by dipped

That's a nice picture of the garden!

My Swaro is the fuzzy model.

[John Russell]

Sancho,

Glad to hear that the ES eyepiece works on the Swaro. How much focus overtravel do you have when focussed at infinity? If you wear glasses this would best be checked with them on.

With its wide AFOV and sealed construction it would seem to be a better buy than the Vixen NLV. I also prefer a rubber eyecup to a poorly executed twist-up version.

I doubt that the Celestron eyepiece would be any better. A good Plössl or orthoscopic might offer very marginal improvements in image quality but with a narrow AFOV and uncomfortably short eye relief.

John

[FrankD]

Originally Posted by John Russell

I doubt that the Celestron eyepiece would be any better. A good Plössl or orthoscopic might offer very marginal improvements in image quality but with a narrow AFOV and uncomfortably short eye relief.

John

The only issue where the Celestron may be better is in the apparent brightness. I haven't looked at the lens configuration of the the Explorer Scientific model but I would expect a fairly complex combination of lens/elements in an eyepiece of that size. From what I remember the Celestron's is simpler...basically a glorified plossl. I will do a little digging and see what I can find.