aa6ww
New Member
Posts: 6
|
Post by aa6ww on Apr 8, 2014 19:35:40 GMT -5
Sounds sensational and i am waiting keenly to be the first southern hemisphere user in MT Victoria NSW (google it) A question i have for Ralph & others: I plan to pu this on a G 11 - just tell me please why i would need the extension pier does it need extra lift so it doesnt hit the tripod legs or is it for eyepiece height ? Any 1200 FL refractor will need an extension pier on a Stock G11, even with the legs fully extended. The mount is just not tall enough to support that length of scope unless you plan to lean way over every time you use it. The 12" extension pier puts the eyepiece at the correct height for both sitting and standing, depending on what object you are looking at in the sky. The scope wont hit the tripod legs, the eyepiece is just too low to the ground, unless your 3 feet tall, then it should be fine. As an example, the mount is a perfect height for a C11, which is what the mount was designed for, hence the name G11. But the C11 is a very compact tube scope. The extension pier is for eyepiece height. The scope is very heavy even more so, awkward to hold as its being mounted on the mount, and it really requires at least 2 people to mount it on a G11 safely, even if you can lift the weight easily. ...Ralph
|
|
|
Post by jamesling1000 on Apr 8, 2014 21:18:28 GMT -5
Hi JRC... Ralph is correct.... The F6 version although is only 1200mm fl, but mine is F8.8, 600mm more or almost 2Ft longer....than the F6 version... And I have a total of approx. 18" or 1.5Ft extension on my losmandy G11 mount... Yet in these picture which was took during one of the recent side walk with the 8" F8.8 Istar, you will understand.... REgards James Ling
|
|
jrc
New Member
Posts: 4
|
Post by jrc on Apr 29, 2014 8:18:34 GMT -5
Thanks James and Ralph. I'll probably put this on my castor enabled mount. Another question is what counterweights do you use: hard to see but have you got 3 x 11 lb losmandy weights there ?
|
|
|
Post by jamesling1000 on May 3, 2014 0:04:27 GMT -5
Hi JRC.
For my 8" ISTAR at F8.8, is 70 lbs, after adding the massive mounting rings, focuser, finder, diagonal and ep.... As such you need 3 X 21 LBS counterweight , in order to get this scope balanced....
For the 8" F6 version, I doubt is less than 50 LBS with all the accessories included.... 2 X 21 LBS counterweight maybe possible, with the weight mounted towards the bottom end of the counterweight bar....
Regards
James Ling
|
|
ivan86
Junior Member
Posts: 10
|
Post by ivan86 on May 11, 2014 7:03:04 GMT -5
The 204mm F6 Comet Hunter has been completely redesigned. It will now be made of thin walled aluminum alloy, have a drastic reduction in size of the back plate and counter cell (therefore further reducing the weight). The counter cell will now taper gradually at an angle instead of the abrupt 90 degree angle. The counter cell will no longer be engraved. I believe the engraving is being moved to the back plate. The dew shield is now retractable and has a new lens cap design. The dew shield moves forward and twists in a bayonet style action to lock it in place. The scope tube is in white with black tube rings. It will have a quality 3.5" rack and pinion white focuser. We believe the weight reduction from the original design is some 40%. The lenses are finished and the tubes and related parts are currently in production. John and Gerry, I am truly excited for you. Your wait will (weight) be worth it. All our scopes will be made in the fashion from now on. Each model will be redesigned as the orders come in. Mike This is the news i was waiting for! When will be possible the purchase of the new 204mm comet hunter from one seller inside europe? Peak2valley for example. Thanks
|
|
|
Post by Mike on May 13, 2014 18:57:42 GMT -5
The tubes are being delivered tomorrow. Of course they must be powder coated etc. All the pieces must be put together and tested so it will be a little while yet. If, some part doesn't fit or something is off well that adds time. I believe we are building six units and four are sold. Of course, we will build more right behind these. I think as we get really close to completion the other two will sell. Getting John a scope is not a problem. If you want one from this run you better act soon.
Mike
|
|
frt
New Member
Posts: 8
|
Post by frt on Aug 28, 2015 11:17:59 GMT -5
Hi,
It has been ages since I reported on my WFT 204. Last weekend I have had my first views since more than 2 years! You all know how things can go in life : busy work shedule, kids to be taken care off, house and garden, etc. Add to this some bad luck with the weather on the nights that I was at my dark observing site, the weekend with perfect weather that I had forgotten to bring my diagonal mirror (aaargh...), the good nights that relatives came visiting (and family comes first don't they), etc...
I thoroughly enjoyed my observing session visiting some old friends : M13, M57, M11, M31, M33, double cluster,North America and Pelican nebula,... It was again confirmation of the good quality of the lens that allows magnifications of up to at least 133x with my Nagler 9 mm (I had no shorter length eyepiece with me) and that f.e. shows a lot of stars in M13 with ease. I cannot understand why people keep insisting that a 200 mm F6 cannot possibly serve up decent images on deepsky objects, they should look through one sometimes and not only rely on theoretical reasoning. M31 and M33 were observed during at least 3 hours, the views of M31 becoming better and better as it got higher in the sky : this is a scope that really starts to show something of the spiral arms and some structure in them at lower magnifications. M33 was too low even at the end of the session to really pull out the best views. While I really like observing the North America nebula with a wider view (3.5 to 4°, as in my Vixen ED114SS), the structure that starts to become visible was really amazing and the Pelican was easy, this was at x34 and a 2° field of view (with 35 Pan).
I can go on and on but I would also like to add that this was my first session with the lighter telescope tube that I made last year. The telescope I have is indeed the very first WFT 200 produced and thus of the earlier (very) heavy kind that I found really on the limit for carrying around and hefting onto the mount, that is probably also another reason that it took so long before using it again. I ordered a tube and dew cap made from 'hartpapier' coming from Gerd Neumann and having the exact same dimensions as the existing aluminum ones, these are very precisely made (0.2 mm tolerance) and can be ordered in any dimension and very precisely cut on measure. Making some baffles, drilling some holes, painting and reassembling was all it took to obtain a telescope 4 kg lighter, meaning 14 kg instead of 18 kg. Not so light as the new WFT but still a vast difference when handling the tube. Total cost was some 200 Euro. I was afraid that the lower stiffness of this material could result in collimation issues through excessive bending of the tube during use but last weekend's session proved that wrong : collimation was done 9 month before and not the slightest miscollimation was observed during the observing night (again an example where practice can prove theory wrong).
Below some pictures of the rebuilt scope, unless you have seen one in the flesh you would hardly notice the difference.
Anyone owning the 'older' WFT can always contact me for more details. Since the tubes have to be ordered in a minimum fabrication length I have asked to cut me 3 pieces of the dewcap. If somebody is interested...
Frank Theys
|
|
|
Post by mikey cee on Aug 28, 2015 13:42:29 GMT -5
Hey Frank that is one nice looking scope. I particularly like the head on shot of the objective lens. Would like to see a more "fuller" view if you don't mind! Mike
|
|
|
Post by nobody on Sept 1, 2015 1:31:47 GMT -5
Continuing on Frank's theme of lightness I was looking at these same tube materials only recently. I chose dirt cheap steel over aluminium and much more costly CF. Since the glass can't be lightened by very much the major limitation on reducing overall OTA weight seems to be the cell, counter-cell and dewshield. Every ounce or gram up at the "wrong end" has to be balanced down at the other end. The heavier the objective "assembly" [including the dewshield] the nearer the cell has to be to the mounting. This in turn leads to ground clearance problems and difficulty of eyepiece access on modern tripods and compact mountings intended for stumpy SC OTAs. Not to mention that the nose heavy OTA just looks so wrong that it offends the eye. With the modern emphasis on portability and rapidly rising [iStar] apertures, perhaps it is time to examine alternative cell and counter-cell materials like carbon fiber or engineering plastics? CNC is so "yesterday!" There is absolutely no reason to have anything more than a hollow shell to house the glass, provide the cell adjustments and to adapt it all to the main tube diameter. The dewshield is a major contributor to mass and greatly increased moment arm but can easily be lightened by the use of stiff modern plastics or CF. The days of domed, private observatories and soaring classical refractors, made of brass and bronze and and iron, are a far cry from the modern Comet Catcher. There is no longer any reason to imitate the 19th century, observatory model as if ponderous mass was still a highly desirable indicator of quality. The reality is that the modern refractor owner usually has to carry his instrument out to the observing site and set up while working alone. Every pound or kilo you can remove from his, or her instrument, is removing a hurdle between him, or her, and their next observing session.
|
|
frt
New Member
Posts: 8
|
Post by frt on Sept 4, 2015 10:04:27 GMT -5
Hey Frank that is one nice looking scope. I particularly like the head on shot of the objective lens. Would like to see a more "fuller" view if you don't mind! Mike
Mike, So you want to see a "fuller" view, aren't we ashamed?
Nevertheless I can oblige, please don't mind the dust on the dewcap.
Frank
|
|
|
Post by mikey cee on Sept 4, 2015 12:13:18 GMT -5
Oh do those multi coatings look good!! Mike
|
|
|
Post by starlite on Oct 28, 2015 19:50:22 GMT -5
A brown shirt man left this at the front door one day.Thanks Mike and Ales. Attachments:
|
|
|
Post by Ales - iStar Optical on Oct 29, 2015 16:16:24 GMT -5
Congratuation! This is a truly gorgeous telescope when you see it fully assembled with a bino-viewer attached. I'm glad it arrived in a good shape and please, follow up with more information and a first flight report. Welcome to a fast growing family of Phoenix WXT 204-6LT owners!! Cheers Ales
|
|
jaymocha
Full Member
Bought me the Asteria 204-8 R35...
Posts: 46
|
Post by jaymocha on Nov 17, 2015 10:54:54 GMT -5
You guys are making me want to get another scope I personally have my eyes set on either a Semi APO or APO in the 7-9" range. That 180mm F/9 Semi-APO lens cell is looking pretty good right now. I really need to get a telescope for my wife you know Jason
|
|
|
Post by Ales - iStar Optical on Nov 23, 2015 13:36:40 GMT -5
Hello Jason, we spent some more time to fine tune this 180 F/9 Semi APO design and we were able to further "shrink" the yellowish halo by additional 25%. So the image quality of these doublets should really be nice. These are NOT APOs but the chromatic aberration should be visible only in form of slight bluish-purplish halo around bright stars. Also, all these lenses will be mounted in our newly developed all CNC machined lens cells. I designed these from bottom up and I believe that these are some of the best lens cells available. They will be more expensive compared to the old "classic" cells but the price difference should be well worth it, in my opinion. Im planning on producing 5 of these newly redesigned 180 F9 doublets by end of April 2016. Complete OTAs should become available by July 2016. There are no immediate plans to produce 204 F10 but we do have design ready and all depends on how these 180mm doublets are going to perform. If OK I will definitely look into 204mm Semi APOs.
Ales
|
|