Copyright 2005 CloudyNights.com
The William Optics FLT-110
(redesigned Summer 2005) Tom Trusock - 10/05
This scope is incredible. The 4 rotating focuser is an astrophotographers dream. Its got beautiful mechanics, excellent construction, and wonderful optics, all as befitting a flagship telescope. I found it a worthy competitor to any other designer optic on the market today. If youre lucky enough to see one in person, Id wager youll be immediately smitten. If youre looking at 4 (plus) apos do yourself a favor and check this one out. <eof> Huh - Whazzat? - You want more? Well Ok. When William Yang asked me if Id be willing to review this scope this last summer I jumped at the chance. Id heard a lot about the FLT in its previous incarnation excellent build quality and top of the line TEC optics. Then William Optics decided to redesign the scope and add a dual rotating 4 focuser. While this is of limited use for visual astronomers, just the announcement was enough to make many of my astrophotographically inclined friends drool. Suddenly, I was the most popular guy on my particular astroblock. I even had friends from Colorado come to see this scope not to mention several other locations in Michigan. (Well, ok, Randy SAYS he wanted to visit me, but it sure seemed like he spent more time with the scope) But Im getting ahead of myself here, so lets back up a bit.
William Optics FLT-110 Aperture - 110mm Focal Length - 715mm Focal Ratio f6.5 Objective TEC Oil Spaced Triplet Focuser 4 Rotating Crayford Retractable dew shield Compression ring adapters included Case and Rings included Base Price - $3295

First impressions

What you get depends on the package you choose, but William shipped me (direct from Taiwan) the f6.5 WO 110mm triplet OTA, a first class aluminum case for the above scope, a set of white 115mm tube rings (power coated white, these are MUCH nicer than the Parallax
Copyright 2005 CloudyNights.com rings I use on my FS102NSV and are a bit more expensive too, but hey), and their top of the line quartz diagonal. Finally WO sent an extension tube and.8x reducer/field flattener with their big box o goodies. Now, Ive seen, owned and used a fair amount of telescopes of all brands, and I thought I was somewhat immune but frankly, my heart beat a little faster as I opened the box. Having seen several William Optics telescopes I was ready for first rate mechanics and a gorgeous presentation. Yet, even so, my first peek took my breath away. WOs telescopes are gorgeous and this is their flagship. Befittingly, its a step above. As compared to any other scope Ive had opportunity to use well, the fit and finish is as good as anything Ive seen. William Yang shot high when he built this one and it shows. Opening the shipping container, I was shocked to see just small the included case is a mere 28 x 8.9 x 9.1 inches I must confess I was expecting something more in line with my TV102 or FS102 case. This is significantly shorter and more compact ergo, much easier to travel with. Its only down side is that there is no room for either diagonal or eyepieces. Opening the case, your senses are assaulted with one impressive telescope. The OTA is a white crinkle finish with black anodizing and gold trim very similar to that found on the Megrez line of telescopes. The white powder coat is both durable and easy to clean. The giant 4 focuser is anodized black, and impressive as all get out. The sheer size of the focuser makes you forget this isnt an 80mm scope at least until you pick it up and get it out of the case. I rather expected it to be a beast, weight wise, but surprisingly it turned out to be rather light. At 13.5 lbs, its only a little heavier than my other, smaller, 4 apos. Mount wise, it tended to ride easier than either the Tak or the TV undoubtedly due to its shorter body. The focal length is 715mm, making it an f6.5, and the lens is a 110mm oil spaced triplet manufactured for WO by TEC. Sliding out the dew shield, were treated to a first. It literally pops into place. Some investigation (and a letter from William) reveals that WO has used recessed spring loaded ball bearings to lock the dew shield. You never have to worry about it sagging or sliding down when the felt gets crushed. If anyone has ever done this before, please let me know, as Im completely unaware of it on any other telescope. The lens cap is an all metal press fit style with the WO logo emblazoned on the front, similar to whats found on their other offerings.

The focuser also looks like their standard focuser but all grown up. The knobs are a hefty 1.8 in diameter, and they are a joy to use. The tension is adjusted by the use of an allen screw located on the bottom of the focuser. That said, the default factory tension was just about perfect. Theres no focuser lock, but there didnt appear to be a need. At the factory set tension, it easily held my heaviest eyepieces and accessories as well as a buddies ST2000 CCD camera with no sign of slippage. Focus travel is 93mm, and the drawtube is calibrated another feature my astrophotographer buddies raved over. A two speed focuser should be available shortly after this article is posted, but wasnt available at the time of the review.

An extended look

While the FLT-110 was a little to much for my Gibraltar, it rode quite nicely both on the DM-4 Tom Peters sent in for review (that ones coming shortly folks), and an LXD75 that seems to have somehow wandered into my garage. Giving the OTA a rap on the side, I found that dampening times on both mounts were similar (the DM-4 was slightly better) at around to 1 second each. For visual use, this should give you an idea of what class of mount works well with this particular scope. While Im a fan of unity finders, I found that I didnt bother with one while using the FLT-110. When mounted on the LXD75, the fast focal ratio of the scope made it fairly easy to find the alignment stars, and Ive always found the goto to be pretty much dead accurate. When on the DM-4, I found I simply spent lots of time scanning the night sky, and honestly, frequently found I didnt care if I got to where I was going or not this scope was just that much fun to scan with. If I did get concerned, I just turned on the DSCs. With a 40mm TV Widefield the 110 yielded nearly a 4 deg true FOV. This was enough to frame the Veil perfectly and a gorgeous sight it made from dark skies. At the GLSG, I setup next to a buddy with a 20 Obsession and we pointed these two at the veil. Both views were equally amazing abet in different ways. Few scopes are capable of delivering larger TFOVs at this aperture.
Comparison to the TV102 and FS102NSV was natural. I found there was a very slight but noticeable gain over a 4 telescope in light gathering ability but for most targets the difference was not readily apparent. I typically found the color correction to be slightly superior in the FLT, and contrast and resolution were on a par. Visually, the optics are impressive. The scope yields a wide, flat, well corrected field the only aberrations I noted had nothing to do with the telescope. Only noticeable at low power, they were due to the excessive size of the exit pupil and the defects inherent in my own eyes (or in the eyepiece). In terms of secondary spectrum (false Courtesy William Optics color) visually - there was a negligible amount. The critical test in the summer / early fall is Vega. Not much is worse (excepting Venus). The very first night I turned the scope toward Vega, I saw nothing but the pure blue white of the star. Turning the scope on the Double Double yielded a clean split at only 73x, with the diffraction rings running unbroken around each airy disk. Picking a random semi-bright star, I defocused and found the fresnel patterns to be remarkably similar both in and out of focus, and the optic had an excellent snap to focus. The zone of confusion was for practical purposes non-existent. I didnt have an opportunity to take this scope through much of a temperature change, so I cant say how the cell and optic handled extended cool downs but for the minor deltas I was dealing with (10 deg) there were absolutely no issues. The scope was well baffled (knife edged) and delivered images that were extremely contrasty with very little scatter. Stars were pinpoints across the field. Although its a mere 110mm this refractor treated me to the hands down best full face view Ive ever had of M33. Both its spiral arms and largest HII region (NGC 604) were obvious in that slap you in the face sort of way. Luna is a prime target for a 4-5 inch telescope especially one with choice optics and one too often ignored. Astronomers tend to gather at new moon, so next summer I think Ill propose a lunar party to let the small scopes shine. In the FLT, Luna was a treat - the range, depth, transition of color and contrast was simply wonderful. While were on the

Copyright 2005 CloudyNights.com moon, Ill note that the scope took magnification very well, and maintained that snap to focus at near stupid high levels. Let me stress just how nice the rotate able focuser is when the scope is mounted on a GEM. No contortions needed. Just loosen, twist and tighten and its at a comfortable position. For many, this feature alone will be worth the price of admission. Overall, how would I rate the optics? Simple. Excellent. This scope is a gem. While Im not a photographer, Ive got a lot of friends who are. At GLSG, I loaned the OTA to Jeff Thrush for a night of imaging. He mounted it on his Paramount and was thrilled with the result. Here, take a look for yourself:

Courtesy Jeff Thrush

Saying hes smitten with the scope is an understatement. Heck, everyone who has seen it has been taken with it.

Perfection?

Pretty close. I had a couple of extremely minor issues with the scope. Frankly, neither was really a problem, but they did cause some head scratching. The focuser has TWO rotation points one that turns the entire focuser, knobs and all, and another that just turns the camera back. When we loosed the one for the camera back (as a photographer would for framing), we found there to be a small amount of nonorthogonal shift / tilt. A consultation with William Yang confirmed this is by design evidently to square up the image plane to the telescope if need be - an unexpected feature. The other was discovered by a friend of mine. If you look down the throat of the OTA in the daylight, you can see that the focuser isnt quite sealed to the OTA. What do I mean? Well, in daytime, you can see theres a very thin sliver of light where the drawtube slides in and out. Now to be fair, this isnt unique to this scope there are other high end scopes with similar construction. But knowing this, I kept a careful eye out for any hints of stray light in the system. In practice I saw absolutely nothing that gave me cause for concern. I also wondered if this increased the possibility of stray light being exposed to the film/sensor plane when imaging, but both astrophotographers I asked felt it was a non-issue. The only real downside is the limited availability of this scope if you want one you may find yourself waiting or calling around. But even so, you wont have to wait years. Oh, there is one other thing probably the most significant concern I had. My personal finances didnt allow me to keep it and it had to move on. Sigh to be independently wealthy.

Summary

William Yang and company have a scope to be proud of in the FLT-110. For the astrophotographer this scope must seem like a dream. Plenty of aperture, fast focal ratio, good correction, 4 focuser, rotating back, a reasonable price, and compared to many other scopes in its class its available without a multi-year wait. For the visual astronomer, its every inch a world class telescope that held its own with the best Ive seen.

Thank you for choosing a William Optics FLUOROSTAR 110, William Optics flagship refractor. This simple step-by-step instruction manual is designed to provide FLT-110 owners with a better understanding of how to operate their new telescope by providing precise, updated information. These instructions will also guide you through how to properly maintain the FLT-110, and how to operate it at its maximum capabilities. Please carefully familiarize yourself with your telescope's parts and functions before operating it for the first time.
www.william-optics www.william-optics.com. c o m

WARNING!

DO NOT USE THIS TELESCOPE UNDER ANY CIRCUMSTANCES TO DIRECTLY VIEW THE SUN.
It could easily cause instant blindness or serious damage to your eyes. To view the sun, use only appropriately designed solar filters that will reject 99.96% of the sun light and heat. Educate your family on how to use this telescope properly during day and night time observations. For further information please contact your local dealer.
Crafting the Earth's Finest Astronomical Instruments

CONTENTS

Getting to know your telescope FluoroStar 110 Specifications FluoroStar 110 Acessories Chart Connection Instructions (Mounting Rings) Connection Instructions (2" Diagonal Mirror) Connection Instructions (Erecting Finderscope) Connection Instructions (Aligning Finderscope) Usage Important Notice Storage and Cleaning Caution for Safety Bundled Equipment Optional Equipment Recommended for This Scope 11 12-16
Getting to know your telescope

Dew shield cover

Retractable dew shield

www.william-optics.com

Extend

Main tube

360 rotatable focuser lock
360 rotatable 2" nosepiece lock

Focuser knob

2" lock screw
1.25" adapter lock screw 2" to 1.25" adapter
FluoroStar Accessories Chart
Above diagram is only for future connectivity purposes. Please contact our Authorized Dealers for accessories purchase.

Connection Instructions

( Mounting Rings )

Step-1

Safely secure the 115mm mounting rings to the WO dovetail.

Step-2

Fully extend the dewshield cover before placing the OTA in the rings.

Step-3

Remember to insure that the mounting rings knobs are tight before operations.
( 2" Diagonal Mirror )
Loosen lock screw for release.
Remove 2" to 1.25" adapter.

Tighten lock screw.

( Finderscope )
Extract the black plastic screw and place the finder bracket on FluoriteStar 110 focuser and attach with lock screw. Connection point for finderscope bracket.
Finder Bracket Lock Screw

Finder Bracket

Insert finderscope into finder bracket.
Unscrew the knob of illuminator. Remove the knob from finderscope.
Insert illuminator into finderscope.

Step-4

Tighten the knob on finderscope. Adjust the alignment screws.

( Aligning Finderscope )

Align the finderscope pointing at the same object as the telescope.

Alignment Screws.

Find a distant object in the telescope with a low power eyepiece.
Align the finderscope by pointing at the same object, then loosen or tighten the alignment screws.
Use a high power eyepiece and repeat this procedure.
View Field of Finderscope. (with WO Erecting Illuminated Finderscope)

View Field of Telescope.

This telescope is also well suited for higher power observations with planetary eyepieces. To calculate the magnification of your telescope and eyepiece combination, divide the telescope focal length in mm by the eyepiece focal length in mm. Keep in mind that the atmosphere plays an important role in seeing conditions, and only the best seeing conditions will support high power viewing. Additional power under less than ideal seeing conditions will not result in an increase in viewable details, and lower powered eyepieces should there be used under those conditions. It's easiest to locate objects using low power eyepieces (20X magnification) and then zoom in by switching to higher powered eyepieces. The largest field of view will be seen using a 12X low power-wide field of view eyepiece. Also remember to let the telescope reach thermal stability for optimal results. A triplet lens takes longer than a doublet to cool down. A stable tripod or mount is recommended for optimal viewing. This includes high quality photography tripods, and German Equatorial mounts, which are designed for astronomical use and include precise tracking of celestial objects. William Optics is marketing a very practical Alt-Az mount too, which will perfectly complement any of its refractors. The Fluorostar 110 has been specifically designed for astrophotography; it will produce excellent results when used with the proper equipment. Being this a high-end astrophotography telescope, it should be mounted on a good mount. Please see our website for examples of photos taken with these telescopes. The Accessories Chart on page 3 provides additional details on photographic accessories for various CCD, digital and film cameras. Optional accessories from WO include mounting rings and plates, super high-quality 2" Quartz o o star diagonals, and 2" Erecting Prisms (45 and 90 ), all of which provide for superior viewing and high quality images. Never aim your telescope or finderscope at the Sun without proper Solar filters installed on the front of the telescope. Doing so for even a moment may permanently damage your vision. Proper Solar filters consist of a filters made by reputable manufacturers, designed to fit tightly over the front of the dew shield. Solar eyepiece filters are not considered safe, and should not be used. With proper front mounted Solar filters, the telescope will not be harmed by viewing the Sun. Contact your Authorized WO Dealer for further information on the brands, sizes, and prices of proper solar filters.

The Fluorostar 110 is designed to work with both 1 1/4 inch and 2 inch diameter eyepieces in various focal lengths, for both daytime and nighttime viewing. Because the Fluorostar 110 is well suited to viewing nebulae, clusters, large galaxies and comets, we recommend the use of high o o quality wide angle eyepieces. The WO SWAN ( 72 ) and UWAN ( 82 ) series eyepieces are available in a variety of focal lengths. Viewing the moon and planets is also impressive at magnifications of 120X when seeing conditions permit.

Important Notice

William Optics warranty does not cover damage to the focuser due to inappropriate tension setting.
This focuser is designed to hold many pounds without problems. If nonetheless your setup requires additional tension adjustment, please use the tension allen screw under the focuser. In order to avoid sagging or denting of the focuser steel reinforcement, it is necessary to adjust tension ONLY when the drawtube is FULLY EXTENDED.
Extend the focuser drawtube to its full 115 mm as in the picture here above before performing adjustment.

Storage and Cleaning

We suggest placing all accessories inside an airtight container with desiccative control. Secondly, remember to store the telescope in a non-humid environment, never leave it in a hot heated environment. If not properly stored, it may develop mildew growth and other preventable build up. Be particularly careful after a night observation that the lens has no dew on it before storing the telescope away. In case the lens surface becomes dusty, smeared, or gets fingerprints or fungus build-up on it, first of all, remove any surface particle by using an air blower, then carefully proceed to wiping the lens gently with a lint-free proper soft cloth. Use a lens liquid cleaner to get the best cleaning result. Make sure you change your cloth to a new one from time to time. The above-mentioned indications are not necessary if you carefully protect your telescope. The multi-layer paint white finish of your Fluorostar 110 is easy to ruin. Please take care of the exterior body tube by wiping it down with a slightly damp soft cloth from time to time. Water should be enough to do the job. Please do not use any organic solvent on your telescope, for example alcohol, benzene and other hazardous chemical as this might ruin it.

Caution for Safety

Caution! Never directly view the Sun with your telescope!
Do not aim your telescope at the Sun without a front mounted high quality professionally manufactured solar filter. Viewing the Sun without the proper protection may result in permanent severe damage to your eyes, and even cause blindness. Contact your Authorized WO Dealer if you are interested in purchasing a compatible and proper solar filter.
Always place the telescope on a flat surface, to prevent it from falling and injuring yourself or others.
Never use the telescope in the rain or in conditions where it may get wet.
telescope is not designed to be waterproof. If the telescope accidentally gets caught in the rain, immediately wipe off all water using a clean dry soft cloth. If the telescope gets totally soaked in water, immediately contact your Authorized WO Dealer for service instructions.
Do not disassemble or attempt to repair your telescope without a written authorization from William Optics Corp., as this violates the warranty terms under the limited product warranty, and negates any guarantee.

Bundle Equipment

1. Aluminum carrying case. 2. Gold plated dew shield cover. 3. 115mm mounting rings. 4. 2" to 1.25" adapter. 5. Various accessories depending on the package.

Optional Equipment

A sturdy tripod for astronomical or spotting scope usage, or a telescope tripod and mount (Equatorial or Alt-Az). A mirror diagonal or erecting prism (The 2" WO Dielectric model is strongly recommended for high quality astronomical viewing. A top quality Dielectric Quartz model is now also available from WO). At least one or two high quality eyepieces (9mm to 40mm wide-field recommended) depending on the application. For astrophotography, a photo adapter plus a T-Mount connection are necessary. William Optics offers a TMB-designed reducer / field flattener optimized for the 110mm TMB Triplet APO lens.

Also available from WO:

WO 2" Star Mirror Diagonals. WO 2" and 1.25" 45 Erecting prisms. 2.5x Apochromatic Barlow lens. 0.8x Reducer / Field Flattener with CCD camera adapter (will work ok, but we recommend the FLT field flattener instead). Super wide angle SWAN / UWAN Eyepieces, 1.25" or 2" versions. DCL 52, 28, 4337 series "Digital Camera adapter Lens for Digital Cameras and Digital Video". Digiscoping adapter: universal adapter for any type of digital camera. WO 2" VR-1 filter improves seeing on bright objects like the Moon. WO 115 mm mounting rings, saddle plate, dovetail plate combo for equatorial mounting. WO 2" Extension Tube.
Recommended for This Scope Diagonal Mirrors
2" Quartz Dielectric Diagonal
2" Dielectric Carbon Fiber Diagonal
99% reflectivity with 1/10 lambda highprecision mirror surface, with elegant exterior design, with 1.25" adapter.
High-quality dielectric coating (99% reflectivity), precision-polished quartz flat in our much-admired, patented mechanics. Our 2" Diagonals are what you need for your best observing sessions. Only from William Optics.
ZenithStar 80 II ED Doublet APO
The newest ZenithStar II generation Doublet APO is a 80mm ED refractor ideal for everyone who needs an excellent back-up scope / guiding scope at an excellent price, or a great first APO refractor, which you can use for planetary work, wide-field imaging, and crisp, high power observations.
Crafting the Earth's Finest Astronmical Instruments

SWAN Eyepieces

1.25" Eyepieces
Super Wide Angle (72 ). 9mm, 15mm, 20mm focal lengths. 5 elements in 4 groups, fully multi coated. Parfocal.

2" Eyepieces

Super Wide Angle (72 ). 25mm, 33mm, 40mm focal lengths, FMC. Generous eye-relief.

UWAN Eyepieces

Ultra Wide Angle (82 ), 28mm (2"), 16mm (1.25"), 7mm (1.25"), 4mm (1.25").

Binoviewer

R e d D o t F i n d e r ( R. D. F. )
This very practical r.d.f. comes with a handy, quick-release bracket included in the price. Centering your objects in the sky has never been easier!

45 Erecting Prisms

2" 45
1.25" 45 with 2" Barrel

1.25" 45

Perfect both for astronomical and terrestrial observations. Revolutionary and sophisticated design, extra-smooth feel.

2" 90

Erecting Prism
High quality prism, coating and finish, for good correct-image views of celestial objects. Perfect in daylight too.

Photo Adapter

Anodized 2" camera adapter for prime focus photography. Standard T ring thread.
E A Z Y- To u c h A l t - A z M o u n t
What is that you prize the most for your wide-field refractor? It's ease of use: EAZY TOUCH is the mount you in need, without by sacrificing our partner stability, looks and portability. Made Switzerland company AOK, this mount allows you to be ready to go in 5 minutes even with a 4" telescope!