Posts Made By: James Barnett

Bleh. Cloudy despite the forecasts to the contrary. Hopefully it'll thin out later tonight. Otherwise, the new moon will push the remaining evaluation out for quite some time.

- Jim

UPDATE:

I just received shipping notice from Clear Vue Optical that my 105mm, F14.4 Vixen-Spec is on the way.

I'll do a quick and dirty shootout between it and the Orion 100ED when I receive the Antares scope. I'm planning a longer term comparison between the two too.

Cheers,

Jim

"They" being the Antares "Vixen Spec" 105mm f/14.4 Achromat and Antares 48" Pier.

My first impression is "What a BEAST!" It's not heavy (maybe 9.5# with the finder attached), but it is LONG. Really, really long. It will see first light this weekend, but I ave formed some opinions about the contruction quality. I would characterize it as "first rate". A bit better overall assembly and finish quality than my 5" D&G. Significantly better fit and finish than my Orion 100ED.

I opted for a 7x50 RA Finder in lieu of the standard straight through model. If you haven't seen one in person, these are el-premo finders. Unlike Meade and Orion finders, these have a very deep dew shield, multi-coated objectives and a focusable eyepiece. The stock tube rings are the standard Chinese made Orion-style 100mm units. The OTA must be a hair over 100mm in diameter (perhaps 102-105mm) because they barely fit the OTA. One of the contributors to this thread who owns one warned me of this, so I have on order some beefier Stellervue Deluxe rings for their 4" OTAs.

I also opted for the 10:1 Micro Focuser rather than the standard one-speed Crayford. Very smooth, but with a little weight installed (diagonal and an eyepiece) it tends to slip unless you tighten the tension knob. I'll tweak it a bit this weekend.

Althought the objective is hawked a fully multi-coated, it appears to instead be coated on all 4 surfaces with MgFl yielding a bluish tint. This seems to be confirmed by ad copy on cetain websites selling this OTA. The spacers are metal, and the objective looks pretty similar to the objective in an old Vixen 102mm f/9.8 I used to own.

The dew shield is an impressive affair. Very long with the interior flocked with black felt.

The attention to detail is impressive; particularly at the modest $650 pricepoint. The overall effect is somewhat breathtaking. I can't wait to capture some photons with it. I will update this thread after first light.

Also after I've played with it for a couple of weeks, I have a face-off between the Antares and the 100ED planned.

Cheers!

Jim

Here's a close-up of the objective...



Note: I do appear in this picture. I am wearing a "parrot green" polo shirt.

The 110mm William Optics Zenithstar triplet comes close to your spec by the numbers. 110mm O.D., f/7, 9# OTA weight and a length of 22.8" with the dew shade retracted. I guess the question is whether the extra 2.8" is fatal to the "travel scope" designation?

- Jim

Bill:

Thanks for the report. I wonder is there may be some differences in design between the 34mm Siebert Observatory Series and the 36mm unit.

I have a 34mm Siebert that I use occassionally in a 12" f/4.9 Dobsonian and it is one of the flatest field and best corrected eyepieces in my collection for edge performance in fast scopes and is the best edge corrected hands down among my "wide field" designs. It is considerably sharper at the very edge than my 27mm Panoptic for example.

The 34mm Siebert has other weaknesses (so-so coatings, some internal reflections, etc.), but poor edge performance isn't one of them. Now I am itching to do a head to head between the 36mm and 34mm Sieberts.

Based on your report on the 40mm I'll have to give those 16mm and 24mm TMBs a look when they are available.

Regards,

Jim

Howdy Floyd. I have no experience with the LXD 650 mount, but have had a 127ED for a couple of years. It is a very well-made OTA. I may be in the minority, but I prefer the Meade's "Giant Focuser" over the 2.7" Astro-Physics R&P focuser I have on a D&G. It is a big, fairly long, fairly heavy OTA and demands a stout mount. I use mine on a Losmandy GM-8 and feel the GM-8 is ovetaxed by the OTA. I am considering moving to an Orion Atlas.

Optically these are very good refractors. Mine was purchased new from Anacortes and was one of the last lot of 127EDs made. It has the user-adjustable lens cell - which is important. Optimal performance requires very acurate lens centering and collimation. Mine arrived well collimated and has remained so during my ownership. It provides great views of the moon, Jupiter and Saturn, does a good job on double stars, and gives very satisfying views of brighter DSOs. It is not 100% apochromatic. At higher magnification (200x+) on Jupiter and bright stars like Vega and Sirius it throws up a small amount of spurious blue-violet. For comparison's sake, it has about the same amount of chromatic aberration as my 4" f/14 Antares achromat and less than the D&G 5" f/10 have curently and a Stellarvue 80/9D I used to have.

Chromatism aside, it serves up a wealth of detail on Jupiter (on the order of 8-9 belts with detail in many of them) and Saturn (Cassini always, sometimes Encke gap, sometimes the crepe ring, always 3-5 subtle bands). Were it not such a chore to transport, set-up and take-down, it would be my lunar and planetary workhorse. As it is, I usually opt for a shorter, lighter set-up out of convenience (usually a 100ED or 150mm MCT) for lunar and planetary observations.

Regards,

Jim

Oh, and here's a link to a shoot-out by some Bay Area astronomers in 2003 between the 127ED and some high-zoot Astro-Physics and Takahashi 5" glass. My experience with the scope is consistent with this report. For the money (my OTA was $1600) it is a good deal. Where money is not an object, the fancier OTAs will absolutely perform better. At $4-5k a pop they had better.

The 127ED gives you 85-90% of the performance of the premium 5 inchers at 33% of the price or even less used.

http://www.cloudynights.com/item.php?item_id=506

- Jim

Mr. Gastaldo:

I thinks these will fit the focuser posts on the 80ED crayford.

Regards,

Jim

http://www.scopestuff.com/ss_fkcx.htm

There's nothing innovative about an 80mm f/11 achromat. Vixen imported excellent scopes in this configuration for decades. Even at f/11, the focal length of 880mm is still pretty short compared to say a F=1500mm 4-incher like Antares sells.

You'll need Barlow "witchery" to get ridiculously high magnification out of a 3" f/11, or some pretty rare eyepieces like a Takahashi LE 2.8mm or Nagler Zoom 2-4mm.

If it's a 3" f/11 apochromatic doublet (ala 80ED but with a longer focal length), then maybe there's a niche. It should be utterly color free in this case.

The biggest problem I see is that faster 80mm apochromats are just fine from a color correction perspective for visual use, and the Burgess' f/11 even if it were utterly devoid of color, would turn off astro photographers who are more demanding generally on the color purity front. Heck, they fuss about the 100ED's f/9 F=900mm configuration.

Seems questionable.

- Jim