- Televue Genesis Owners Manual Pdf
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Televue genesis owners manual raymond reach truck manual - free ebooks download 4bt raymond easi opc30tt manual tricia joy crx raymond r40tt manual pdf health care finance solution manual the raymond corporation - forklifts and lift trucks taco bell suzuki dt 50 82 service manual. View and Download Genesis G90 owner's manual online. G90 car navigation system pdf manual download. This Televue 4' scope replaced the Genesis before it and was then replaced by the Televue 101. It included a clam shell ring, 2' diagonal, r&p focuser, and built in sliding dew shield. Optically it is a 4 lens system in two doublets, the rear one contains a fluorite element the front contains 'Special Dispersion' glass. The Genesis Pro® has an adjustable draw stop that provides the archer with a 'solid wall,' making shooting with a mechanical release aid easier. Use an Allen Wrench to turn the Draw. Read all WARNINGS, as well as the entire instruction manual, before attempting to use this bow! This bow is NOT a toy. Adult supervision is strongly recommended. Virtual Guide is a mobile manual to help customers utilize various features of Genesis through augmented reality(AR), virtual reality(VR), and 3D contents. Download for Android.
Celestron C102HD Refractor1) Meade Starfinder Equatorial 6' Reflector(6' f/8 Newtonian, DC RA drive, 6X30 finder, 25 mm MA, $650+$65 shipping)(No Longer Available)
A competent performer, and an excellent starter scope. Comparing this to my own, 20 year old Meade 6' reflector, it's amazing how little they'vechanged over the years. The optics on the sample I saw were very good.I also like the giant, 'sideways' RA scale for those who use setting circles.The finder is serviceable, and the Sonotube cools quickly and evenly. You'llwant to replace the mounting rings (they're actually a pair of tightly clampedmetal straps) at the earliest opportunity.I have only one complaint, and it is somewhat serious: the focuser. How Meade could spec such a cheap part on an otherwise well-built scope is beyond me. Not only is it made out of plastic, but it's the cheesiest, cheapest, thinnest plastic you can imagine. Even lightly banging the focuser against the wall (i.e., when moving the OTA outdoors) will shatter it to pieces.And if you allow the tube to roll around in the back of your car, it will eventuallycome to rest on the focuser, knocking it out of alignment. The drawtube on theunit above has 1/8' to 1/4' play in any direction. Budget another $50-$75 for adecent focuser.
No one seems to make 6' f/8 Newtonians any more, and that's a shame. Amateur astronomers have eschewed them recently, preferring the convenience of Schmidt-Cassegrains, the tack-sharp images of modern apochromatic refractors, or light-gathering capabilities of the new-generation Dobsonians.That doesn't mean that there still isn't a place for a good, old-fashioned Newtonian, like this one. If you're new to astronomy, any of the Starfinderscould keep you busy for years. Recommended. Just get rid of that focuser.
Update, 4/00: Meade recently dropped the price of this telescope to $499+ $65 shipping.
2) Celestron C6 (Brief Impression)(6' f/5 Newtonian, 6X30 finder, Polaris mount, 18 mm Ortho, $899, NLA)
Looking like a 'fatter' C4.5, these older 6' rich-field scopes are wortha look on the used market. The optics on the unit I saw were very wellcorrected for an f/5 system. I saw very little spherical aberration, but I did notice a trace of astigmatism.On 25 mm eyepieces (and longer, presumably), coma started to creep in near the edges. In fact, while watching the field near the Ring Nebula, I watched stars drift through the field. As they approached the edge ofthe FOV, the tiny points of light would spread out into little curves. It's a fun scope for deep-sky sweeps.
Televue Genesis Owners Manual Pdf
Celestron didn't seem to sell verymany of these, and for the reason, you have to look at the price. Forcomparison, the new Starsplitter 6' f/5 sells for about $530. The olderMeade 6600 and 645 models were also much less, and are worth seeking out. A convenient scope. It doesn't 'feel' like a 6' when you're moving it around;it feels smaller (that's supposed to be a compliment.) The Polaris mount is a known quantity and is more than suitable for the job. It may also come in handy for some of your other OTAs. Recommended, provided you get one at a decent price.
3) Meade Starfinder 10' Dobsonian(10' f/4.5 Dobsonian reflector, 5X24 finder, 25 mm MA, $599+$69 shipping)(No Longer Available)
A sleeper. Excellent value in a mid-aperture Dobsonian. It's only $50 more than the 10.1' Coulter, but has a pyrex mirror, finder, rack-and-pinion focuser, a better eyepiece, and superior fit and finish.In the spirit of cheap Dobs, the Starfinder feels more like a work in progressthan a completed telescope. Just looking at it, sitting in my living room, Ican think of a half-dozen or so things I could do to change it. The finder and focuser are made of incredibly cheap plastic, and should be put out of their misery at the earliest opportunity. The bearings need improving, and the feet should be replaced.
If you order one, have a drill and some hand tools ready; you may have tocorrect some of Meade's drilling errors, as I had to. Also, the scope isdifficult to collimate, as the secondary is somewhat undersized (this leadone cynical observer to refer to the scope as the '9.5-inch Starfinder.') The OTA looks identical to the equatorial version, but the mirror cell ismade of particle board instead of metal. The Sonotube is drilled to acceptthe other Meade finders. I installed my spare 8X50 unit. While it workswell, it makes the tube front heavy, and I have had to rig a counterweightsystem using Velcro and modeling clay. The star test was actually pretty good, with very little spherical aberrationin the center of the FOV. At the edges, however, coma and astigmatismcreep in. Using Nagler and Panoptic-type eyepieces helps to tighten upthe image near the edges. Use them if you have them.
The cheap mirror cell sometimes 'sticks' when you're collimating it, requiringyou to remove it, 'unstick' it, and re-assemble it. Not my idea of fun in thedark. Fortunately, the scope holds its collimation reasonably well, even duringfrequent transport.Also, the short 45' tube means you'll be stooping over and kneeling a lot. Getyourself a chair and save your back. And the jury's still out on the long-termdurability of the Sonotube.Other than the above concerns, the 10' Starfinder performs far better than I hada right to expect. It has generous aperture, good optics, it's easy to transport,it's fun to use, and it's cheap enough that I don't worry about it all the time. Its short, stubby profile even exudes a dash of personality. A bargain and a keeper.
Update, 4/00: Meade recently reduced the price of this telescope to $449,+ $69 shipping.
4) TeleVue 85(85 mm f/7 ED doublet, 2' diagonal, 20 mm TV Plossl, about $1850 street)
I spent about 2 hours with one of these under good, clear skies, with the moonat first quarter. At first glance, it's easily mistaken for one of the new, green-tubed Prontos, but it's just a little longer, and weighs about 8 lbs, to the Pronto's6.6. It comes in a Pronto-like soft carrying case.
The star test was nearly perfect, with just a trace of undercorrection. I noticedno false color on the limb of the moon. With a 7 mm Nagler, it easily splits thedouble-double and Epsilon Bootes. With a 35 mm Panoptic and a 2' O-III filter,all sections of the Veil are possible. I wound up looking at a lot of the summerMessier objects, as well -- the views were unfailingly crisp and refractor-like.The TeleVue 85 was set up beside my Takahashi FS102, and an older TeleVue Oracle was not far away. Comparisons were interesting, but there were no surprises. The Oracle and 85 both showed the same freedom from color, although the 85 went a little 'deeper', due to its slightly larger aperture.
Both the Oracle and TV 85 are a good leap ahead of the Ranger/Pronto series. However, the FS102 is still a step ahead of the 85 in terms of light-gathering abilityand perhaps sharpness as well (I felt the same way at Stellafane, comparing an 85 to a nearby Traveler.) However, a comparably equipped FS102 will run you about $2800, and the Traveler would ring the till at around $2600, once you add the 2' diagonal. Viewed in this manner, the 85 is almost a bargain (if $1850 for a 3.35' scope can ever be called a 'bargain!')In short, the TV85 is a marvelous portable, wide-field, refractor. If I didn't alreadyown 60 mm, 70 mm, 80 mm, and 102 mm refractors, I'd probably buy one.
5) TeleVue Bizarro (Brief Impression)(85 mm f/7 ED doublet, similar to TeleVue 85, above, with built-in binoviewer)
Leave it up to Al Nagler to come up with something like this. Take an innocent TeleVue 85, chop off the last five inches from the eyepiece end, add TeleVue'sexcellent binoviewer, and what you get is a 'Bizarro.'Most telescopes cannot accommodate the use of a binoviewer without the use ofa barlow. Nagler circumvents this by cutting off the end of a TeleVue 85, justenough so the attached binoviewer can be used without the need for a FOV-robbing barlow lens.In switching back and forth between the 85 and the Bizarro, I found it hard tonotice any light loss through the Bizarro, although I know it's there. The viewsthrough this scope on deep sky are breathtaking; images take on a 3-D qualitythat's simply hard to describe. On the Double Cluster and on M31, for example,I was convinced that these now-familiar objects were floating in space, in frontof a backdrop of pinpoint stars.At Stellafane, deep-sky through the Bizarro, along with the Veil through a 2' OIII-equipped Traveler, provided my most memorable views this year. Wonderful scope. Very pricey (about $2600.)
6) TeleVue Genesis SDF(101 mm f/5.4 refractor, 20 mm Plossl, 2' diagonal, case, was $2299, NLA)
These popular refractors throw up an impressively bright, wide-field view.The design is a hybrid, and involves more optical sleight-of-hand from AlNagler. The doublet objective lens operates at f/12. Near the eyepiecelies a second doublet, which brings the optical train down to f/5.4. Thesecond doublet uses a fluorite element, which is said to reduce chromaticaberration to nearly imperceptible levels. The scope is very well-built,almost overbuilt.
As a result of the design, the Genesis is a lot larger and heavier than a conventional 101 mm f/5.4 telescope. It weighs 11 lbs, and is as largeas my FS102. It's almost twice as large as a Traveler, even though ithas a shorter focal length.The sample I saw was slightly undercorrected, and had almost no false color. Stars at high power had that round-ball-on-black-velvet look that is the hallmark of any high quality refractor. The wide field is really stunningon the right objects. The entire Veil can be seen at once. M31 and itssurrounding field looks great with a low power 2' eyepiece.
I spent an evening comparing a Gibraltar-mounted Genesis with the FS102and an A-P Star 12ED. Jupiter came up, and we watched a double transitfor nearly an hour. With such a short focal length, you wind up usingbarlows and tiny eyepieces to boost the magnification, which gets a bituncomfortable. I don't think it's a coincidence that many Genesis ownershave 2.5 mm Lanthanums in their eyepiece cases.Apparently, all this glass doesn't bother the Genesis. With the new 5Xbarlow, and a Nagler Type II in place, you'd have 4+4+8=16 elements inthe optical path. Owners tell me there's no breakdown in image quality.The Genesis held its own against the AP and the Tak. I did think the Genesis was a tad less sharp, but this was not immediately obviousunless you did a direct A/B comparison. The Gibraltar mount is quite smooth, although it won't point at the zenith (guess where Murphy's Law usually places the object you want to view?)I will confess, I love TeleVue's Genesis, and have wanted one ever since Ifirst saw an ad for one. Alas, circumstances, financial and otherwise, haveprevented me from obtaining one. Now they've been discontinued, replacedby the identical-looking TeleVue 101 (about $2600), which uses exotic glass elements in place of the conventional glass in the Genesis. Original versions were f/5. Prices for all used versions have been steadilyrising. Buy now before the price gets unreasonable.
7) Astro-Physics Starfire 130 EDT(130 mm f/8 triplet apochromat, OTA only, $2450-$3250 depending on vintage)(Note: see related article)
My, oh my! What a scope. Available in 1992, these triplets were discontinuedsome years back, but have now been resurrected for 1998. Do not confuse thiswith the 130 f/8 doublets, which are not as well corrected (but still superb, world-class scopes) or the more popular new 130 mm f/6 EDF models.
This scope has perfect optics. No spherical aberration, no false color. It is agood step up in performance from the Starfire 120 mm f/8, and despite having only an 18% light-gathering advantage over the Star 12, it feels like a much larger scope. The 130 will tax a GM8; a G11, or one of Astro-Physics' own mounts, is preferred. It may not look all that large at first glance, but at nearly 20 lbs, the Star 130 is a serious chunk of glass and steel.The OTA is beautifully-made, almost a work of art. The focuser is incredibly smooth. This, coupled with the no-doubt 'snap' focus, gives the user a reassuringfeeling of micro-control while using the scope.
In viewing tests, the Star 130 gives a little more of that 'big refractor' performance, compared with the Star 120 or the Takahashi FS102. We caught a dual shadow transit on Jupiter, and the black dots were tack-sharp in times of steady seeing -- as if someone had used a hole-punch on the planet.Compared to my FS102, the Star 130 shows more detail in the cloud bands on Jupiter, and gave slightly sharper images on the floor of Copernicus. Later, we repeated the star test, and again found no aberrations. At high magnification, I thought I might have seen some undercorrection, but it was strictly academicand I wouldn't swear to it.Note that the AP 130 has an aperture advantage over the FS102. I didn't havean FS128 handy, but I suspect the 5' Tak would give the Starfire a good, hardrun for its money.The only major problem you will have with this scope (other than the cost of settingup a complete, working rig) will be obtaining one. There's always a waiting list,and used ones seem to be selling for at or above the retail value.Looking through one, it is easy to see why Astro-Physics refractors are the scopesby which all others are judged. If you are one of the lucky few who can afford thecost and the wait, consider yourself very fortunate. And invite me over sometime..
8) Celestron C102ED Refractor(102mm f/9 ED doublet refractor, 6X30 finder, 20 mm Plossl, GP mount, $2450, NLA)
Celestron has offered many telescopes with the 'C102' moniker, and it does getconfusing. 'Regular' C102 models are achromats, and operate at f/9.8. Theywere coupled with a GP mount and sold for about $1400. This ED version soldfor about $1000 extra. Finally, there was a fluorite version. All of the abovehad black tubes, and were made by Vixen.To make matters more confusing, the 102 achromats and fluorite versions arenow sold (in white tubes) by Orion. The price of the fluorite 102 has dropped to$2300, which is a major bargain. Finally, the newer C102 achromats, which aresupplied with the cheap-n-dirty 'HD' mounts, are made in China and sell for onlyabout $600, which does not seem like nearly enough money.
The C102ED I saw has superb optics. False color is almost non-existent; I wassurprised at how color-free an f/9 ED doublet could be. The color correction ismuch better than the ED refractors currently sold by Meade, for example. Thisscope will reveal a wealth of detail on Jupiter. It is a good leap in performanceahead of the C102 achromat, which will throw a slight purple halo around bright objects. The star test was nearly perfect.Set up next to the Takahashi FS102 and the AP130 EDT, the Celestron lost outby a tiny bit on demanding objects like close doubles and fine planetary detail.I should add, these differences were small. I don't think you'd notice them unlessyou had the scopes set up, side by side, the way we did.Like the Tak and the A-P, the C102ED is a reference-class instrument. Everyoneseems to want a fluorite refractor these days, which means that prices on the used market for these ED versions should drop. They're worth seeking out.
9) 12.5' Mag 1 Portaball Reflector(12.5' f/4.8 Open Truss Dobsonian, $2795+ depending on configuration) (Note: see also Todd Gross' Review of this same scope)
Peter Smitka's Portaball Dobsonians are different. Looking like conventionalopen-truss Dobs coupled to a bowling-ball type mount favored by ATMs intimes past, the Portaballs seek to combat certain position/comfort issues thathave plagued traditional Dobsonians.
First, the sphere moves incredibly smoothly along its three teflon pads. Ifound myself waiting for an object to drift out of the FOV, just so I could movethe telescope! Also, the whole truss can be rotated, so you can place theeyepiece at any height you wish. Nice. Those of you who have lugged around big, heavy rocker boxes are going to be shocked at how tiny the base is (it's about the size of a collapsed and flattened tripod.) Finally, there are manythoughtful features, including tethered hardware, easily-read markings, andconvenient handles on the sphere.If you want to move the whole scope, you will have to be careful. You can't justset the sphere on the ground. Any scratches on it can affect its motions. Tothis end, Mag 1 provides an inflated inner tube to set the sphere on, should you decide to move the scope in the middle of your observing session. And if youfind the motion of the scope too smooth, you are instructed to wax the sphere ('Honey, I'm going out to the garage to wax the telescope!')
Televue Genesis Owners Manual Free
By coincidence, I happened to review the model once owned by Todd Gross,and in fact drove down to pick it up at his house for a friend (we had a niceconversation, by the way.) It's a small astronomical world.The scope, when set up, looks like a giant white Astroscan with truss tubes.It is very small and light for a 12.5' Newtonian, and the parts will easily fitin just about any car you can name. According to the instructions, this onehas a killer mirror: 1/28th wave. Images were very sharp, almost refractor-like with a 35 mm Panoptic on the Double Cluster (although the full moon prevented us from seeing very deep.) On Jupiter, the scope had some serious competition from expensive glass nearby(the C102ED above, the FS102, and the AP130EDT.) On this night, the refractorswon out, but as Todd warned us, the Portaballs are extremely sensitive to seeingconditions. He reports the Mag 1 would outperform his own 130 EDF, when conditions allowed. Still, I thought Jupiter and Saturn were wonderful, and a healthy leapahead of most Newtonians on these bright planets. It significantly out-resolves my 10' Meade, which has unusually good optics for a cheap dob. I can't wait to seesome galaxies under dark skies. There are a few disadvantages. You can't use digital setting circles. It willhave some balance issues with unusually heavy (or light) eyepieces. It looksfunny. And the price is steep for a 12.5' - about (or over) $3000, depending onwhat options you order.Still, the Portaball succeeds at its intended goal: providing great optics in aneasy-to-use, comfortable package, with smooth mechanics that will spoil you.New versions are f/5.
Update, 9/20/98: Under dark, moonless skies, the Portaball is a wonderful deep-sky scope. The scope's design allows you to move effortlessly from object toobject. The ability to change eyepiece height with a twist of the wrist is a terrificluxury. Because of the convenience of the Portaball, I noticed I was expending less energy 'using' the telescope, which allowed me to conentrate on viewing. I think duringa long oberving session, a Portaball user is going be be a lot less tired, mentallyand physically, from not having to wrestle with his telescope and mount.We caught a number of late-summer deep sky objects and verified the almostrefractor-like sharpness of this telescope. Astigmatism crept in when using32 mm eyepieces (the TeleVue Plossl and the Brandon.) On planets, thescope was delivering images close to those in a nearby Meade 178ED andan AP 155 EDF.
10) Celestron C102HD Refractor(102 mm f/9.8 achromatic refractor, 'HD' mount, 6X30 finder, 20 mm Plossl, $650)
I bought this mostly out of curiosity. Many of us (myself included) who werefans of the C102GP ($1400) did a double-take when this latest version of thevenerable 4' refractor debuted in early 1998 for only about $650. This didnot seem like nearly enough money for a quality 4' achromat.Because I already owned a half-cousin of the 'HD' mount (these cheap mountsare springing up everywhere these days!) I ordered the OTA and set it up onmy Super Polaris. Yes, I know these Taiwanese mounts are supposed to beas good as the SP, I read the ad copy just like you do. I'll stick with the SP,thank you.At first glance, this newest, Chinese-sourced 'HD' scope looks just like theprevious (Vixen-Japan) version. However, there are some differences.
Televue Genesis Reviews
Thetube is no longer 114 mm in diameter, it's now 102 mm, which means theOTA isn't baffled as well as before (there are 3 on mine.) The tube is so skinny it looks like a longer version of the C80 (of course, the new Chinese C80s have also been downsized.) The whole OTA feels lighter and cheaperthan the old C102GP version, as well -- there's so much plastic, it almost feels like there's nothing inside.Also, the focuser, while good, is a bit rougher than the Vixen version. However,in a strange turn of events, the coatings on the new lenses are a deep, richgreen, which appears darker than the light blue MgF coatings on the C102GP.Also, mine has a 2' focuser. Other C102HDs I've seen only have a 1.25'focuser, so there may be multiple versions of this scope floating around.
I tested the C102 along with its natural competitor, Meade's new 102ACHR/500.The Celestron is slightly undercorrected (1/8 wave or so) and shows some chromatic aberration at 100X on Vega and Jupiter. The Meade is slightly overcorrect-ed and has somewhat more false color. We both agreed that the C102's opticsare a bit sharper - I could bring in detail on Jupiter more easily than on theMeade.Other than the false color, I couldn't find much wrong with the C102's optics.I did a brief late-summer Messier tour (M8,M20,M17,M16,M11,M26,M13,M57,M81,M82,M51, etc) and split some doubles. The C102 never let me down.I even went hunting for some obscure NGC galaxies in Pegasus (sorry -- noStephan's!) Only when attempting to resolve low-level detail on Jupiter did I wish for my Takahashi.We agreed that the Meade's color and sharpness problems (relative to theC102HD) resulted from its too-short f/9 focal ratio. Still, if one must havethe widest FOV from a 4 inch achromat, the 102ACHR/500 will do. Otherwise,I think I'd recommend the C102 to anyone seeking an inexpensive 4' refractor.It has better optics, and costs 30%, or about $350 less than the Meade, andeven on absolute terms, it's darned good. You just have to live with somefalse color.
The scope performs almost identically to a 102 mm f/9.8 TeleHoon, which inprinciple is the same telescope (Hoon assembles OTAs using Vixen opticsand parts.) Set up side by side with the same eyepieces, the C102 throwsup slightly more false color, and gives up a tiny bit of sharpness as a result.Note that I do not know how good the QA is on these new scopes comingfrom China. However, if all of them are as good as mine, these new C102HDtelescopes must qualify as a major bargain. Highly recommended.
End Telescope Reviews, Page 4
Back to Home Page101 mm f5.4 Apochromat Refractor (4.0' aperture)
Discontinued April 2001, replaced in August 2001 with new NP101 telescope.
Provided for information purposes only.
Provided for information purposes only.
Above: TeleVue 101mm telescope optical tube assembly with lens shade retracted (without optional mount) |
DEVELOPMENT
Compared to the other popular telescope designs (reflecting and Catadioptric) the well made refracting telescopes will offer the most natural, high contrast, three dimensional views of the brighter objects; these have certainly have been the choice of professional visual astronomers. The 4 and 5 inch aperture telescopes pioneered by TeleVue proved the concept of using a refractor for deep sky observing, and for imaging. If one could build a large enough mirror telescope to show what details a comparable refractor could show, then the field of view through the mirror systems would be relatively narrow. However, most refracting telescopes up to the early 1980's were relatively high magnification instruments affording relatively narrow fields of view. Recent optics innovations had resulted in relatively fast telescopes of f9 or so, compared to the previous common f12 to f15 ratio Achromat this afforded wider fields of view better suited to deep sky observing. Since the best apochromatic refractors such as the 101 are the most difficult and costly in raw materials to make well consistently, these telescope will cost notably more than competing designs - but the waiting lists and high resale values testify to the confidence that the astronomy community has in telescopes such as these. It was an original 'Renaissance' telescope (Serial No. 1019) evaluated in the March 1985 issue of 'Modern Photography' magazine that earned 'excellent' ratings on resolution tests, and 'High' ratings for contrast with praise that included 'with image quality beyond ordinary camera lens'; knowing the 101 is a notable improvement we can only imagine how such a telescope might be reviewed. And to our surprise in 1986 'Audubon' magazine rated the original 'Renaissance' as the top refracting telescope in a comparative survey of birding telescopes (the 'Questar Field Model' a compact Maksutov-Cassegrain telescope was rated top choice over all); but we found it hard to believe that too many birders would haul a 4 inch Apo telescope very far.
The '101' and 'Renaissance' telescopes are a fifth generation TeleVue four element refractor design succeeding the original 5 inch 'MPT' system introduced in 1982, the beautiful brass 4 inch aperture f5.5 'Renaissance' telescope introduced in 1984, the 'Genesis' 4 inch f 5 telescope of 1988, and the 'SDF' 4 inch f5.4 of 1993. Al Naglers patented four element design is based on the 'Petzval' concept where a two element air spaced objective lens at the front of the telescope passes the light through to a second doublet lens positioned at the rear of the telescope and before the focuser. The doublet lens group functions to 1) reduce the effective focal length, and 2) reduce or eliminate curvature of field.
Above: TeleVue '101' telescope optical arrangement; 1. air spaced doublet objective, 2. mounting collar, 3. doublet, 4. 2' focuser, 5. 'Everbrite' 2 inch mirror diagonal, 6. 2' to 1.25' reducer, 7. eyepiece (20mm Plossl is standard) |
Incorporating TeleVue's best 101mm aperture air-spaced 'SD' special dispersion doublet lens with a fluorite doublet telecompressor/field flattener this provides flat field wide angle views. Accepting 1-1/4' or 2' accessories including the highly regarded TeleVue Radian, Nagler and Panoptic eyepieces, magnifications as low as 10X and a tack sharp field of view of as wide as 4.9 degrees! A multi layer coating process of the lenses, and on all the TeleVue eyepieces prevents light reflection off the surface of, or between the lenses; this process virtually eliminates ghost images and flare and it improves color rendition. All of this achieves a dramatic increase in image contrast and actual light transmission, with a corresponding reduction in flare caused by internal reflection. The result is a very fast, wide and flat-field system so well corrected that panoramic nature or star and planetary images are breathtaking. A collapsing lens shade aids portability. Its' uses include birding, video and film photography as well as astronomy.
The TeleVue '101' series telescopes introduced in 1998 are the first large TeleVue Apochromatic refractors which Company Seven found to be truly competitive in optical performance with the best 4 inch aperture Apos ever made; providing visually false color-free, sharp, clear and high contrast images. The TeleVue 101 remains the worlds fastest, flat field apochromatic 4 inch telescope - while the brass 'Renaissance 101' also remains the world's most beautiful.
PERFORMANCE
The objective lens of the 101 is of an SD air spaced doublet design where two lenses (crown and flint) are matched to work as one; the positive element is of a fluorocrown substitute with special dispersion glass. In fact this design allows excellent color correction without annoying purple fringes (secondary color) common to less sophisticated achromatic refractors, and better than a number of older triplet and modern doublet apochromat designs. A fluorite doublet telecompressor/field flattener lens group provides flat field, wide angle capability. Spherical correction is very good also with the air gap objective contributing to this correction. Images of the stars and the planets are presented in their natural colors, daytime objects viewed at commonly used magnifications will appear quite three dimensional and sharp and contrasting. The objective's four air to glass surfaces have a multi-layer anti-reflection coatings that improves overall light transmission across the visual wavelengths and from 400nm to well beyond 700nm. Overall the complete system provides about 180 times the light gathering power of the unaided human eye. On most nights, the settling down time for the lens is on the order of minutes: from room temperature to sub-freezing conditions it rarely requires more than 30 minutes to acclimate.
The lens is so well figured that the consistency between telescopes is quite good, and each is capable of operating at very high magnification cleanly (with 'Barlow' or 'Powermate' optional lenses). This telescope reaches that threshold necessary to routinely obtain meaningful views of the planets showing several bands and their shades of color (beige, tan, browns) on Jupiter - observe the four largest moons of Jupiter and their shadows cast on the surface as distinct discs as they transit across the planet! Study the Cassini division and banding on Saturn, the polar cap and dark markings on a fiery red Mars. With an eyepiece that shows 1/2 degree field or so (such as a 5 or 6mm 'Radian') take a walk on our apparently three dimensional Moon possibly resolving objects on the Moon as small as 4.4 km in diameter. Or follow its' terminator throughout the moon phases (a optional neutral density filter is suggested to tone down its brightness). With an optional white light solar filter (such as our Baader AstroSolar film) observe Faculae and Sunspots on the Sun! With our optional Hydrogen Alpha filters (either the DayStar ATM or University series) observe Faculae, Sunspots, the Peach-fuzz like photosphere on the Sun as well as the sheer curtain like Prominences as they erupt from the Sun out into the blackness of space!
Above: Similar to the 101's focuser, shown is the TeleVue 2' Focuser and 2' diagonal in the textured finish as provided with the 102 telescope (54,505 bytes). |
Televue Genesis Telescope
In fact, one of the finest advertisements ever published for a telescope concept is the book Deep-Sky Companions: The Messier Objects where the author Stephen O'Meara sought to keep the drawings relevant to the amateur. To produce the highly detailed drawings of these celestial objects Stephen chose to observe with the second generation TeleVue 'Genesis' telescope (4' aperture, 500mm f5) which has since been replaced by the improved 101 and 102 apochromatic telescopes. This book has become one of our best advertisements for the versatile, readily transportable fast 4 inch (10cm) refracting telescopes. Similarly to keep things simple, and relate as much as possible to the average amateur observer Stephen chose to use the telescope on the simple but sturdy TeleVue 'Gibraltar' alt-azimuth mount with Ash Wood tripod. He equipped the telescope with only a modest selection of accessories: TeleVue 22mm 'Panoptic' eyepiece (providing 23X, 2.85 Degrees Actual Field of View), a 7mm Nagler eyepiece (71X, 1.08 AFOV), and a TeleVue Barlow lens to increase the magnification by 1.8X.
The 101 compares favorably against many telescopes in field of view:
- 1.7 at 25X for a common 102mm f10 achromatic refractor,
- 1.4 at 31X for a typical 8' f6 reflecting telescope,
- 1.3 degrees at 32X for an 8' Schmidt-Cassegrain (operating with an optional telecompressor lens)
- 1.3 degrees at 32X for an 3-1/2' Maksutov-Cassegrain.
In fairness, the cost the TeleVue 101 (equipped with either an optional Alt-Az or Equatorial mount) is positioned at a higher cost than most of the above telescopes. And as a practical matter for some applications in astronomy the nominal match of the '101' exit pupil to an average dark adapted human eye will be obtained at magnifications of between 17X and 15X. The best performance will be obtained at all magnifications if a wise choice of good quality oculars is made however, since the 101 telescope incorporates a field flattening element then it is compatible with several of the simpler eyepiece designs. Again consider that an optional good quality 'Barlow' or 'TeleVue Powermate' amplifying (negative) lens, or optional long eye relief TeleVue 'Radian' ocular (introduced in 1999) will usually be put into use to attain the highest use able magnifications which are necessary for observing small bright objects including planets, and double stars.
The telescope includes the TeleVue 2 inch diameter 'Everbrite' diagonal (or 'zenith') mirror. The 'Everbrite' mirror introduced in 1999 features a very high-tech dielectric coating (developed originally for military optics used in hostile environments such as blowing desert sand) which provide optimum performance and years of use. This new TeleVue 2 inch diagonal has no aluminum or other reflective metal coating. Instead, the reflective surface consists of 52 layers of thin film oxides similar to those used in anti-reflection coatings. The coatings are deposited by an electron beam evaporator at a high temperature. The result is that reflectivity is above 99% over the entire 4000 to 7000 Angstrom photo-visual range. Thin film coatings have extremely low surface scatter compared to aluminum or enhanced aluminum coatings; examination with a laser source shows approximately a five fold improvement in surface scatter. The mirror diagonal provides a comfortable viewing position for the observer by diverting the image at the rear of the telescope off axis by 90 degrees to the side, with minimal degradation of image quality. The view when using the telescope as it is provided will appear to be right side up, and is reversed left to right; this is not usually a problem for astronomy or nature observing because the image quality provided by the high quality mirror and 2 inch diameters panoramic oculars is exceptional.
While Company Seven does offer optional 45 degree inclined image erecting prisms, these prisms can only accommodate 1.25 inch diameter oculars. Furthermore, the erecting prisms will not provide image quality to equal that of a good mirror diagonal; this is particularly perceptible at higher magnifications. However, for moderate to medium magnification applications where one needs correct images (such as to read numbers, etc.) then the optional prism should be suitable.
For film photography, the telescope (with our optional camera adapters) becomes a super sharp 540 f5.4 ED ultra telephoto lens, showing about 4.54 degrees across the diagonal of a 35mm camera film plane. And for CCD imaging operations the telescope at prime focus can show about 0.86 degree across the diagonal of a common 2/3' detector (such as that employed on some of our SBIG CCD systems. Optional techniques and hardware permit imaging of the planets, or of wildlife at much higher magnifications.
With optional 2' and 3' long x 2' diameter extension tubes, it is possible to observe at close distances for use as a 'long distance microscope'.
The TeleVue 101 can operate on any of a number of optional German Equatorial or for extreme ease of use or portability consider our alt-azimuth mounts including:
- our Losmandy Hollywood General Machining portable mount systems, or
- our Astro-Physics portable 'Go-To' computer controlled mount systems
- our TeleVue 'Gibraltar' portable alt azimuth mount and tripod.
Furthermore, this is a telescope one can grow with since most of the accessories that one would buy for this telescope are upwardly compatible with any larger telescope that one is likely to buy at Company Seven.
MECHANICAL CONSTRUCTION
The 101mm has a fully machined aluminum front cell to house the objective lens and focuser housing. The objective lens is permanently aligned to the barrel as is the focuser assembly. Unless subjected to gross abuse this telescope will provide many lifetimes of service with no need for any other than cleaning of the front surface of the objective lens using common camera lens cleaning techniques. Its construction is extremely rugged to allow it to withstand all the handling that is typical of airline travel. However, some caution should be practiced not to damage the focuser pinion of any telescope; our experience with this focuser is that with routine handling this will not happen and in its hard shell case is routinely transportable.
The 101 telescope incorporates a retracting Dew Shield/Lens Shade. Also provided is a thread-on Lens Cover of machined aluminum in a tube assembly that has an overall length of only 33 inches with it's 2 inch diagonal attached. The precision TeleVue 2 inch focuser is a rack and pinion design with a tension/lock screw which helps to lock focus for uses including photography; this is one of the smoothest focusers made. The 1-1/2 inch diameter machined aluminum hand knobs resemble model car brushed aluminum mag wheels. The knob hand grips are rubber covered to facilitate operation in all extremes; even when wearing gloves all the controls on the telescope are easy to manipulate. The set screw has an easy to grip knurled head, this permits one to adjust resistance of the focuser to its draw tube thereby compensating for heavy loads that might otherwise cause an unintended shift of focus. The lock screw that is in the draw tube ring at the proximal (to the operator) end of the draw tube adjusts tension to retain accessories such as the 2 inch diagonal, or a camera; this set screw is captive so it will not easily come out.
The mounting collar is a two piece bracket. On one side of the collar is an Allen head screw (wrench provided - but not necessary), while on the other side is a tension adjustment knob. This design permits one to adjust the grip on the barrel so that the telescope may be easily moved back and forth to compensate for changes of accessory loads that may affect the balance of the telescope on a mount. However, telescopes with the length and weight of the 101 require that this collar be snugged tight to reduce or eliminate undue wavering of the telescope in the collar. For those interested in applications such as astrophotography or CCD imaging, Company Seven can provide optional conventional mounting rings (by the pair) which will also accommodate options including photo guide telescopes. The fabric lined mounting collar has three 1/4'-20 tpi threaded sockets in the base to facilitate mounting the telescope onto a variety of tripods and mounts. At the 10:30 and 1: 30 o'clock positions on the top of the collar there is a dovetail platform to accommodate a variety of TeleVue options including the 'Starbeam' sight, or a 'Piggycam' piggyback photography mount.
The telescope is furnished with a TeleVue 90 degree 2 inch diameter 'Everbrite' precision mirror diagonal (1/10th wave P-V quoted). This diagonal has a durable reflective coating described above. The male 2 inch barrel is threaded to accept 48mm photo and visual filters. The interior is fully anti reflection ribbed and coated. A 2 inch to 1.25 inch reducer adapter is furnished to permit the use of 1.25 inch diameter accessories. This diagonal permits an observer to employ any of a broad selection of 2 or 1.25 inch diameter oculars. The lock screw with a knurled head that is at the proximal (to the operator) end of the female 2 inch barrel adjusts tension to retain accessories such as the 2 to 1.25 inch reducer or lenses; this set screw is captive and so it too will not easily come out.
The objective (front) lens cell, focuser housing, mounting collar, and diagonal are anodized in a lustrous black satin. The barrel is powder coated in the customers choice of either a mottled Forest Green, or textured neutral Ivory (as illustrated above). The powder coat feels like a textured smooth plastic covering which is quite comfortable to manage even in extreme cold or damp climates. The interior of the optical tube assembly is lined with an anti-reflective covering unique to TeleVue telescopes, which is then finished with anti reflective black paint.
Also included with the telescope is a die cut, foam lined hard shell carrying case with latch closures. This case is 38-1/2 x 10-1/2 x 9-1/2 inches in dimension, and it has extra space to accommodate several 1.25 or 2 inch oculars, camera adapter, etc. And in a nice touch the case has a cutout provision for the 'Starbeam' or 'Qwick-Point' sights. The case will fit into the overhead storage area of most commercial aircraft (one exception being the L-1011). However, many airlines do not permit such 'oversize' packages on board; even if they do you will not be too popular with other passengers so you might ask a Flight Attendant to store the telescope for you - possibly in the garment bag storage area.
The telescope, in itsw case is well padded and then packaged for delivery within one box, and then this is placed into another box. We suggest that telescopes such as this be sent by a priority air service (Fedex,ÊUPS, U.S. Mail, etc.) to reduce risks of loss or damage in shipment.
TELEVUE 101mm f5.4 TELESCOPE SPECIFICATIONS
Specification | |
---|---|
Clear aperture: | 101.95mm (4') |
Focal length: | 540mm (21.26') |
Resolution (visual): | 1.15 arc seconds |
Resolution (photo): | 260 line pairs per mm |
Coatings: | Multi-layer |
Magnification range: | 10x to 360x |
Tube assembly: | Powder coat finish, 30' aluminum tube; fully baffled, permanently aligned cell construction |
Focuser type: | 2 inch rack and pinion |
Focuser Travel: | 2-3/8 inches |
Telescope length with diagonal: | 83.8cm (33') dew cap retracted |
Weight with 2' diagonal: | 12 lbs. (5.5 kg) |
Weight in carrying case: | 21 lbs. (9.6 kg) |
ShippingWeight: | 32 lbs. (14.5 kg) |
Shipping Dimensions: | 40 x 13 x 10 inches |
35mm prime-focus field: | 3.7 x 2.6 x 4.5 degrees @ f10.8 |
35mm field with 2x Barlow: | 1.9 x 1.3 x 2.4 degrees @ f10.8 |
Standard Eyepiece: | TeleVue 20mm Plossl (20X), 1.25 inch Dia. |
SUGGESTIONS
- Gibraltar Mount Head and Ash Tripod: An incredibly and portable 17 lb. (7.7kg), simple to use mount that cradles a telescope at its center of gravity for ideal balance at any viewing position.Right: TeleVue Ash Gibraltar Mount with optional 101 telescope, Starbeam sight, oculars and SkyTour CPU on accessory tray.The mount head is made of fully machined of aluminum which is black anodized, with brass elevation bearings and azimuth nylon bearing providing smooth vertical travel from 10 degrees below the horizon up to 85 degrees overhead, and smooth full 360 degree rotation. Clutches on the elevation axis permits the operate to compensate for changing accessory loads, or with the Azimuth control to lock the telescope in place. The tripod is made of American ash, in a two section extension design providing a range of 3 feet up to 5 feet, with accessory tray/leg brace. The 'Gibraltar' mount solved a problem of ease of use for those who are frustrated by the weight and relative complexity of equatorial mounts, and it provides a mount far better suited to terrestrial applications than an equatorial mount or common camera tripod would be. These mounts remain available with either a beautiful ash tripod in natural finish with black trim, or a walnut finish with solid brass journal and plated brass trim. (Yes, ash is the hard wood used to make baseball bats). Since it's introduction the 'Gibraltar' head has been engineered to accept optional encoders to feed a 'Digital Setting Circle' CPU such as that offered by TeleVue and third party units; this helps one to navigate the sky and find objects that might be hard to find particularly from suburban settings.
- 'Starbeam' Sight: Beautifully machined and black anodized aluminum, on a quick release machined hardware. Battery powered illuminator is adjustable in brightness; it projects a 10 arc minute diameter red dot onto a transparent 40mm clear aperture window so that the dot appears to be over wherever the scope is pointed. Six arc minute accuracy make 'star hopping' easy.
- Eyepieces: Plossl, Orthoscopic, traditional Erfle and wide angle eyepieces show sharp images only in the center of the field when employed with telescopes such as this. These are acceptable as long as you realize this limitation, and find this unobtrusive. If you object to less than perfect images at the edge of the field, then Company Seven recommends the TeleVue 'Nagler', 'Radian', or 'Panoptic' eyepieces. These oculars provide the most clear, and flat field images and will bring out the most in your '101' (and many other) telescope. A 35mm to 55mm focal length eyepiece can also make the main telescope also serve as your finder. Please refer to the brochure and the test report/data generated by Company Seven enclosed with our telescopes for descriptions of these items and additional accessories.
- Barlow or TeleVue 'Powermate' Lens: Company Seven suggests you consider any of a number of 1.25 inch or 2 inch diameter Barlow lenses that we offer to double or more than triple your magnification. Contact us for suggestions on how to to best meet your goals.
- TeleVue 1.25 Inch Prism Diagonal: 45 degree 1.25 inch diameter precision image erecting prism diagonal with high transmission coating. This is a good choice for those who must have an image erect and correct left to right view, and who do not intend to use the telescope at higher magnifications.
- If a customer saves the packing boxes, then he might be able to actually ship the telescope ahead for a vacation in Hawaii, or some other paradise. But the card baord boxes and the carrying case can not tolerate repeated abuse, or travel by common carriers. Company Seven does design and offer custom Airline Transport Association approved transport cases for those telescopes and mounts which we sell; one who travels quite a bit would find these to be cost effective protection, and convenient as well.
Eyepiece | Magnification | Actual field of view | Exit pupil |
---|---|---|---|
35mm Panoptic | 15x | 4.11 degrees | 6.54mm |
31mm Nagler Type 5 | 17x | 4.42 degrees | 5.80mm |
27mm Panoptic | 20x | 3.24 degrees | 5.05mm |
22mm Nagler Type 4 | 25x | 3.3 degrees | 4.11mm |
22mm Panoptic | 25x | 2.64 degrees | 4.11mm |
20mm Plossl | 27x | 1.81 degrees | 3.74mm |
17mm Nagler Type 4 | 32x | 2.58 degrees | 3.18mm |
12mm Nagler Type 4 | 45x | 1.81 degrees | 2.24mm |
9mm Nagler | 60x | 1.31 degrees | 1.68mm |
8mm Radian | 68X | 0.88 degrees | 1.50mm |
6mm Radian | 90x | 0.67 degrees | 1.12mm |
5mm Radian | 108x | 0.56 degrees | 0.93mm |
Eyepiece | Mag. w/2X 2 Inch Barlow | Actual field of view | Exit pupil |
---|---|---|---|
35mm Panoptic | 31x | 2.05 degrees | 3.27mm |
31mm Nagler Type 5 | 35x | 2.21 degrees | 2.90mm |
27mm Panoptic | 40x | 1.62 degrees | 2.52mm |
22mm Nagler Type 4 | 49x | 1.65 degrees | 2.06mm |
22mm Panoptic | 49x | 1.32 degrees | 2.06mm |
20mm Plossl | 54x | 0.95 degrees | 1.87mm |
17mm Nagler Type 4 | 64x | 1.29 degrees | 1.59mm |
12mm Nagler Type 4 | 90x | 0.91 degrees | 1.12mm |
9mm Nagler | 120x | 0.65 degrees | 0.84mm |
8mm Radian | 135X | 0.44 degrees | 0.75mm |
6mm Radian | 180x | 0.33 degrees | 0.56mm |
5mm Radian | 216x | 0.28 degrees | 0.47mm |