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General Telescope Questions (applies to many scopes)

Mounting Brackets and options

What is the L-Bracket and what does it do?
The L-Bracket that is supplied on many of the 80mm and 66mm scopes is a removable bracket that can be used to directly attach the scope to the standard ¼-20 bolt used on photographic tripods. It is sturdy enough to hold the scope and most accessories.

The L-bracket on the new batch of ZenithStar 66 SD (orange and blue versions) will fit in the Vixen-style clamp of William Optics Eazy Touch alt-az mount.

What other mounting options are available?
There are a number of other mounting options including mounting rings from WO, mounting rings from other parties, and dovetail brackets that can be installed onto the rings or in some cases directly onto the L-Bracket.

Are there dovetail brackets that attach directly to the L-Bracket so that I don't have to purchase rings?
Yes, there are several. Users have reported several solutions on the WO Yahoo Group at various times, several links to the messages are provided below.

One option is provided here
http://groups.yahoo.com/group/William-Optics/message/6718

Another option seems to be here
http://groups.yahoo.com/group/William-Optics/message/6601

Can the L-Bracket be moved or adjusted for better balance?
Some people have been able to achieve better balance by taking off the L-bracket and reversing it, so that it points backwards and moves the balance point, but this depends on your setup.

What size mounting rings do I need?
Check the WO website specifications for any questions but the current sizes are listed as

ZenithStar 66mm scopes – Tube Diameter is 75mm
ZenithStar 80mm scopes – Tube Diameter is 90mm
Megrez 80mm scopes – Tube Diameter is 90mm
ZenithStar 105mm scope – Tube Diameter is 114mm

Can I use rings provided by other manufacturers?
Sure, but be careful in all cases, since it has been reported by several users that its very easy to scratch the finish of the scope while tightening the rings down on the OTA (optical tube assembly). Even the WO tube rings have been cited to cause this problem sometimes, so be careful, and perhaps check the edges or add some self sticking felt that is available at hobby and craft stores if you are concerned that installation of the rings may scratch the finish of the tube.

Optics Questions

What is the APOGRADE upgrade and how hard is it to install?
The APOGRADE is a user installable lens cell replacement for Megrez, ZenithStar and other brands of compatible 80mm refractors, that brings the same excellent optics found in the ZenithStar Fluorite Doublet APO scope, to any scope it is installed in.

A complete review with detailed instructions for the Megrez II, is available online in the Files section of the Yahoo group, written by me, Timm Bottoni, titled 「APOGRADE Fluorite Lens.doc」 to help users decide if the APOGRADE is something they want.

MAKE SURE you contact WO to determine what is needed for your scope before ordering, to ensure that you have the correct model and accessories needed for the APOGRADE to work for your installation.

How does the APOGRADE perform when installed by the user?
See the review mentioned above, for a complete set of comparison photos.

Is the installation the same for the ZenithStar scopes?
No, the installation is not identical, but the steps are similar. The biggest difference is that the baffles are designed and installed differently in the ZenithStar 80 models, and the baffle assembly ring is required in order for the installation to be completed. Detailed instructions were provided by Keith in the Yahoo Group in this post.
http://groups.yahoo.com/group/William-Optics/message/8128

What else is required for an APOGRADE to work?
A 2 inch focuser extension tube is required, available from WO, or other sources, in order to reach focus once the APOGRADE is installed. Also, since the lens cell is longer, the user will be required to modify the foam in their carry case, if they have one, if they want the scope to fit nicely.

What's the difference between ED, SD, FL glass?
To some extent these terms are used correctly or incorrectly by a variety of manufacturers of telescopes. The properties of the glass, and the glass type is often not widely made public by WO, or other companies, to perhaps prevent the copying of the design. There are a variety of articles available on the Internet, and published books regarding optical designs that can be found if you are interested in learning more about this.

Keep in mind that the optical performance of a telescope, in particular a refractor depends on much more than knowing what the glass types are. It is in fact, the overall design and execution of the lens that matters the most, in order to achieve a high performance refractor!

What's better, a doublet APO or a triplet APO?
It is not usually a matter of better or worse, but rather of the application required. There are drawbacks and advantages to both.

Refer to this very good article by Tom Trusack on CN:
http://www.cloudynights.com/documents/80mm.pdf

How do I know which scope I want?
Ask our Yahoo group members for advice!
http://groups.yahoo.com/group/William-Optics/

It works and the advice is free! Most existing users are happy to share their experiences, and their photographs with other members, and don't forget to use the SEARCH function on the group's home page.

What do the Longitudinal Chromatic Aberration charts on the WO website mean and how do you read them?
Scott Walker in the Yahoo group provides an explanation here.
http://groups.yahoo.com/group/William-Optics/message/7184

What does 「Co-designed by TMB」 mean?
Thomas M Back, is a leading optical designer http://www.tmboptical.com

There is also a Yahoo Group here http://groups.yahoo.com/group/tmboptical

Searching that group will reveal a number of posts from Thomas regarding his cooperation on various projects with WO. In the specific case, the TMB fluorite doublet lens was a lens designed by TMB and WO optical designer together.

Focuser Questions

How do I adjust the tension on my single speed Crayford focuser, its too loose or too tight?
Most of the problems with the focuser tension can be solved by understanding how the two different but related adjustment screws work.

The large silver knurled thumbscrew (it might be something other than silver) is the focuser lock screw. It thread through the focuser, and has a nylon tip on it, and makes direct contact with the focuser draw tube, as it moves in and out of the focuser assembly. Its only purpose is to lock the focuser in place to prevent it from accidentally moving or sliding during photography. It should be unscrewed enough to prevent any grad on the focuser tube, at all other times.

The small inset screw is used for adjusting the tension, and is tightened or loosened using a small allen wrench. It's most likely a 2.5mm allen wrench, and an entire metric set of allen wrenches can be purchased for a few dollars at most hardware stores. The screw puts pressure on the bar that holds the focuser shaft in place against the draw tube. This tension adjustment screw is tightened or loosened to provide the proper tension. The key to adjusting it is to first have the locking thumbscrew mentioned above, completely loosened so that it does not put any drag on the travel of the focuser tube. Then the tension screw can be adjusted to provide the proper tension, and is best done with the scope in a near vertical position, with the diagonal and eyepiece or camera attached so that it's easy to tell when the focuser holds well on its own, yet operates smoothly.

How do I adjust the tension on my two-speed Crayford focuser?
The two-speed focuser knob does not have any tension adjustment of its own. See the files located in the WO Yahoo Group for installation instructions provided by WO and for Timm's Tips provided in a review of the two-speed retrofit.

Adjusting the two-speed focuser is the same as adjusting the one speed focuser, with the difference being that the tension adjustment screw now serves two purposes for the Megrez and perhaps other models. It acts as both the focuser tension screw, and the f astening stud for the two-speed assembly. The Timm's Tips article gives more complete instructions, but it has been found that it takes some playing around with adjusting the tension, and tightening the f astening finger tightened knurled attachment nut to get things operating smoothly.

My two-speed focuser has hard and easy zones as it turns, is something wrong with it, and can I fix it myself?

Again, follow Timm's Tips found in the WO Yahoo Group Files section for complete instructions, but I found that the hard easy zones were a result of not having the two-speed assembly knurled f astening nut tight enough. If the nut is not tight enough, it causes the two-speed assembly to flex the main focuser shaft just enough to introduce hard and easy zones. This can often be adjusted out by tightening the unit more securely to the focuser.

General Accessories Questions (by product)

Binoviewers

What scopes do the binoviewers work with?
Most refractors and SCT scopes will work with binoviewers, as will many reflectors, however there are cases reported where scopes with a smaller amount of focuser travel, i.e. some reflectors will not be able to use binoviewers. This depends somewhat on the design of the focuser, and depends on the focal travel needed for the particular eyepieces.

The ZenithStar 80 Short model was optimized for use with binoviewers. The Megrez Triplet ED, Megrez Fluorite Doublet and ZenithStar Fluorite Doublet, and ZenithStar 105 can be binoveiwed easily too.

What does the Barlow nosepiece do and why is it needed?
The Barlow nosepiece (1.6x) is provided for easier focusing with any telescope that requires it to reach focus. Some telescopes can not reach focus without it. WO markets an optional 2x nosepiece corrector/Barlow too.

I can't get the image to focus correctly in both eyes, what do I do?
The focus of each eyepiece is independently controlled by the using helical focusers that are independent. Make sure the compression rings are tight on the set of two identical eyepieces, and adjust one first in the middle of the range, then adjust the other until the entire view is in focus.

Focal Reducer / Focal Flattener 2」 .8x w/CCD adapter

Can the WO Focal Reducer be used on any scope?
The WO focal reducer will work on most scopes from WO, but it is not recommended for the Triplet Super APO. Other options exist for this model, and the WO web site should be consulted for further instructions on what does work. Check the WO web site for up to date information. Users reported very good results with Orion/Skywatcher/Synta ED 80 and larger. This reducer/flattener is recommened for refractors with f/ratio f/6-f10.

Can other brands of Focal Reducers be used on WO scopes?
Yes, many brands of focal reducers have reported to work including the TeleVue models, the Meade and Celestron SCT models, and others. Refer to posts in the Yahoo group to search for success and failure reports of various users' experiences with other products.

What are the benefits of the Focal Reducer?
Its purpose is to reduce the focal length of the scope, which usually provides a wider field of view, and a flatter field of view for photographic use.

Diagonals

Can a standard 2」 diagonal be used in a 66mm WO scope?
Not all, even with the additional WO 2」 adapter, a standard 2」 diagonal will not have enough inward focus travel to reach focus with eyepieces. The 66mm scopes are threaded to accept SCT standard threaded devices, and the WO 2」 adapter will work with photographic accessories, and most 1.25」 diagonals. WO makes a special 2」 SCT diagonal for those who desire a 2」 diagonal.

Barlows

Can the WO 2」 2.5X Barlow be used in all scopes?
Apparently not, since it has been reported by users that it needs a fair amount of inward focuser travel to reach focus on some scopes with some eyepieces.

Its been my experience that adding a Barlow to scopes (at le ast the ones I have tried) brings the focal point inward towards the scope, so keep this in mind, because if the particular scope/eyepiece combination is already near the most inward point of the focuser's travel, there is likely to be a higher probability that you will not have enough inward travel with some barlows.

Specific Telescopes and Questions

Differences between the different lines of scopes available

What's the difference between the ZenithStar and Megrez scopes and their optics?
A large number of posts on the Yahoo group can be searched for answers to these questions and since the WO product line has changed and continued to change, its advisable to use the Search function to look up specifics. But here are some handy posts that might help

http://groups.yahoo.com/group/William-Optics/message/6496
http://groups.yahoo.com/group/William-Optics/message/6532

ZenithStar Family Telescopes
ZenithStar 80 (80mm)

What lens does the ZenithStar 80 use?
The standard Zenithstar 80 uses an 80mm doublet lens design, with a focal length of 480mm. It's fully multicoated, and is an improved achromatic lens design.

Can the lens be collimated or adjusted by the user?
The lens design is a cemented doublet that is permanently aligned at the factory, and is not user adjustable.

Can it be used for solar observations then?
With proper equipment (solar filters, wedges etc) it can be used without problems.

ZenithStar 80 Short (80mm)

What's special about the ZenithStar 80 Short?
It has a reduced length, that allows it to work with WO binoviewers without having to use the Barlow lens that is included, allowing it to reach focus without changing its magnification

ZenithStar 66 Petzval ED Semi-APO (66mm)

Can a standard 2」 diagonal be used in a 66mm WO scope?
Even with the additional WO 2」 adapter, a standard 2」 diagonal will not have enough inward focus travel to reach focus with many eyepieces. The 66mm scopes are threaded to accept SCT standard threaded devices, and the WO 2」 adapter will work with photographic accessories, and most 1.25」 diagonals. WO makes a special 2」 SCT diagonal for those who desire a 2」 diagonal.

If you have questions about what will work or not, contact WO directly with the list of items you plan to use with it to avoid being disappointed.

ZenithStar APO Family Telescopes
ZenithStar 105 ED Triplet APO (105mm)

Which is better – the ZS105 ED triplet or the Fluorostar 110 triplet?
Tom Trusak provides insight in this discussion here
http://groups.yahoo.com/group/William-Optics/message/7806

ZenithStar Fluorite Doublet (80mm)

Is the Red Anniversary model still available and will more be made?
This model was a limited production run, celebrating the 10th Anniversary of William Optics. It is still available after a second production run was built, but its not clear if more will be made after these run out, or if it will be made in black. WO will decide this based on market demand, but the plan was to make this particular model an Anniversary

ZenithStar 66 ED Triplet APO (66mm)

For a great review of the 66ED Triplet vs. the 66SD Doublet read Tom Trusak's report http://www.cloudynights.com/item.php?item_id=1395

Can a standard 2」 diagonal be used in a 66mm WO scope?
Even with the additional WO 2」 adapter, a standard 2」 diagonal will not have enough inward focus travel to reach focus with many eyepieces. The 66mm scopes are threaded to accept SCT standard threaded devices, and the WO 2」 adapter will work with photographic accessories, and most 1.25」 diagonals. WO makes a special 2」 SCT diagonal for those who desire a 2」 diagonal.

If you have questions about what will work or not, contact WO directly with the list of items you plan to use with it to avoid being disappointed.

ZenithStar SD Doublet APO (66mm)

For a great review of the 66ED Triplet vs. the 66SD Doublet read Tom Trusak's report http://www.cloudynights.com/item.php?item_id=1395

Can a standard 2」 diagonal be used in a 66mm WO scope?
Even with the additional WO 2」 SCT extender/adapter, a standard push-in 2」 diagonal will not have enough inward focus travel to reach focus with many eyepieces. The 66mm scopes are threaded to accept SCT standard threaded devices, and the WO 2」 SCT adapter will work with photographic accessories, and most 1.25」 diagonals. WO 1.25」 push in diagonal instead, does not require any additional accessories to come to focus.

Also, WO makes anl 2」 SCT diagonal for those who desire the benefits of a 2」 diagonal; this will come to focus without any additional accessories..

If you have questions about what will work or not, contact WO directly with the list of items you plan to use with it.

Megrez Family Telescopes
Megrez Baffles

The internal baffle slid down the inside of the tube when it was cold out one night, what do I do now?

Note: this should only be an issue on Megrez scopes in really cold weather.

I had this happen to me on my Megrez II 80 SD, when it was really cold out, and I heard the baffle sliding back towards the focuser when I tilted the scope up. The baffle is made of a series of flat black foam rings, glued into one assembly that fits tightly inside the tube of the scope.

Why does it suddenly loosen up and slide then? When it's really cold out, the metal of the tube contracts, but the air inside the foam contracts more, and the foam tube can slide. I fixed it myself by applying self sticking black felt circles, used for putting on the bottoms of items that might scratch the surface of a table or shelf. These are sold all over the place, and are a very inexpensive fix, to keep it from sliding backwards again. I put 4 inside the tube and it has not happened again, and I had the scope out in some pretty cold weather.

If you have any concerns about doing this yourself, call WO or your local dealer before trying to do this, or reading on.

If you want to do this yourself, be advised that it requires you to unscrew the tube from the focuser, which on my Megrez II SD was easy to do. It may or may not be the same on your scope, so again, call WO if you have any questions or concerns about this process. The lens assembly easily unscrews as well, and you may need to be working with an empty tube to get it back into place, depending on which way it has slid.

The original placement of the baffles is 58mm from the front, according to Daniel at WO

Also – when the tube and foam are at normal room temperature, it will not slide easily in the tube. It will be a very tight fit, which I think is normal, so be careful not to tear the foam when trying to slide it into place.

Megrez 80 Fluorite Doublet APO (80mm)

What is different about this model?
This model uses the same optical lens assembly as the one originally offered in the ZenithStar 80 Anniversary model, and is a high regarded 80mm Fluorite APO doublet that has a focal length of 555mm. Because of this it requires a 2」 focal extender to reach focus, because the original Megrez tube design was used and not modified. It was codesigned by Thomas Back (TMB) and William Optics and made exclusively by William Optics for its refractors and APOgrade lens upgrades.

Megrez 80 ED Triplet APO (80mm)

Why does the ED Model require a 2」 extender to reach focus?
The optical assembly has a focal length of 560mm, but the tube's length was kept

at the same length as the original 500mm focal length optics. WO did this for various reasons, but the end result is that the focuser needs more outward travel to reach focus for viewing with standard eyepieces, so it requires a 2」 extender.

Megrez 80 II SD Semi-Apo (80mm)

Is the 80 II SD still available?
No, the Megrez 80 II SD Semi-Apo is no longer available from WO, however

some dealers may have remaining stock, and used models can sometimes be purchased on Astromart (http://www. astromart.com).

You should consider other Megrez models or ZenithStar models instead.

What lens is in the 80 II SD?
The lens is a fully multicoated 80mm air-spaced doublet.

Can the lens be collimated or adjusted by the user?
It depends on the lens batch, but generally yes, the lens can be adjusted using the three nylon screws in the lens cell by someone with the proper knowledge and experience. I have carefully adjusted / collimated mine, but its important to understand what is needed before attempting any adjustments. The process is not hard, but is not something that usually needs to be done once it's set, so if the star test looks good, it can be left alone. The key to collimation is to have a good bright star, Polaris is my usual choice, and to make sure the scope is in thermal equilibrium. The optics and the tube should all be the same temperature as the outside environment, or any collimation attempts will results in making things worse. And don't confuse optics that appear to change while its cooling with poorly collimated optics. Glass is a good insulator, and the metal tube is a good conductor, and I have seen my optics go through a range of good, to poor, to good while it's cooling. This is especially true when it's very cold outside, and star tests will reveal all sorts of aberrations, including pinched optics, astigmatism, coma shift, and others while the glass elements cool down.

I find the scope cools down the quickest when the tube is pointed downward, and the diagonal is installed so that the warm air can leave the tube at the top – which of course makes sense since warm air rises.

Fluorostar Telescope
Flourostar 110 Triplet APO (110mm)

Which is better – the ZS105 ED triplet or the Fluorostar 110 triplet?
Tom Trusak provides insight in this discussion here
http://groups.yahoo.com/group/William-Optics/message/7806

Are there any reviews on the Fluorostar 110?
Yes – Tom Trusak did an in depth report on CloudyNights
http://www.cloudynights.com/documents/flt110.pdf

Spotting Scopes
Toucan 50 (50mm)

Binoculars
7 x 50 ED

I cannot find much info about these…
There is a thread on CloudyNights.com that includes some useful information:
http://www.cloudynights.com/ubbthreads/showflat.php/
Cat/0/Number/694293/page/0/view/collapsed/sb/5/o/all/fpart/1/vc/1

8x42 APO

I heard WO would apply Phase Coating to these, is it done now? How can I tell?
Yes, they now come standard with phase coating on prisms and improved FM coatings.

WO does not market non-phase coated version any longer. The warranty card specifies P.C. for phase coated versions.

8x42 Semi-APO

Eyepieces

SWAN Eyepieces (40mm, 33mm, 25mm, 20mm, 15mm, 9mm)

Are there any reviews written about the SWAN eyepieces?
There is one posted on CloudyNights here:
http://www.cloudynights.com/documents/swan.pdf

And a review of the 20mm on Astromart here
http://www. astromart.com/articles/article.asp?article_id=233

UWAN Eyepieces (28mm, 16mm, 9mm, 4mm)

Are there any reviews written about the UWAN eyepieces?
There are a number of discussions ongoing on CloudyNights.com forums, and in the Yahoo Group but when an official review has been posted it will be listed here.

Zoom Eyepieces (8-24mm)

Are there any reviews written about the Zoom eyepiece?
None yet, but the product is so new at this point that its likely too early to see a formal review.

Mounts

EZTouch Mount

Will the EZ Touch Mount be sold separately from the tripod?
Yes, the pricing is listed on the WO shopping site here
Tripod alone - https://www.william-optics.com/wo_shop/catalog/product_info.php?products_id=140

Mount alone - https://www.william-optics.com/wo_shop/catalog/product_info.php?products_id=139

Are there any reviews written about the EZTouch Mount?
None yet, but the product is so new at this point that it's likely too early to see a formal review.

You can find many comments on Cloudy Nights:
http://www.cloudynights.com/ubbthreads/showflat.php/
Cat/0/Number/788735/page/3/view/collapsed/sb/5/o/all/fpart/1

http://www.cloudynights.com/ubbthreads/showflat.php/
Cat/0/Number/834269/page/0/view/collapsed/sb/5/o/all/fpart/1#Post863453

http://www.cloudynights.com/ubbthreads/showflat.php/
Cat/0/Number/754463/page/5/view/collapsed/sb/5/o/all/fpart/1

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/
Number/776977/page/0/view/collapsed/sb/5/o/
all/fpart/7#Post863035

http://groups.yahoo.com/group/William-Optics/message/7861

Why there are no slow motion controls the EZTouch Mount?
Because they are not necessary!
Refer to: http://www.cloudynights.com/ubbthreads/showflat.php/
Cat/0/Number/865533/page/0/view/collapsed/sb/5/o/all/fpart/1

Is it easy to install this mount?
Very easy! Refer to: www.william-optics.com/wowebs/prod_acc/
mnt_eztaltaz/manual.pdf

GT One Mount

Is the GT One Mount available?
The mount is no longer made, but is sometimes sold used on various sites like Astromart.

It was discontinued in 2004, and at the moment there are no plans to run a new production batch.




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