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Optical & Mechanical Telescope Competition

Homemade telescopes can be entered in our competitions to be judged on optical quality and/or several mechanical categories. Certificates are awarded at the Saturday evening program for the best instruments entered. Read the details so you know the rules and what to do, then Register your scope or instrument below.

Master Class Competition

Masters Class Example
An example of Master Class ATM work by Allen Hall and Dick Parker
An example of Master Class ATM work by Allen Hall and Dick Parker

Our Master category for highly skilled Optical and Mechanical Competitors was new in 2016... and a huge success.

  1. The purpose of the Master Class is to encourage first time entrants to enter their scope without feeling they must be ready to compete at the level of a master. It is also intended to allow for an avenue for previous winners, judges and professionals to enter their own creations made for amateur use and purposes.
  2. Previous winners of 1st place in any category must enter in the Master Class if they wish to enter again in that same category.
  3. Anyone desiring to compete with the "high achievers" may enter as a Master, but only those mentioned above will be required to do so.
  4. Members of the judging committee must not judge in the years in which they are entering the competition.
  5. In case of controversy, the head judges will decide on classification of entries, and their decision shall be final.

First Homemade Telescope Certificate

In order to further encourage and recognize telescope building, we are offering a certificate of recognition for first time telescope makers. You do not have to enter the competition if you do not what to, but you must bring your first homemade telescope to Breezy Hill and display it. Please register ahead of time online with the form below, and check in at the judging table. You will be awarded a certificate recognizing your efforts in building and displaying your first homemade telescope at Stellafane, and your name will be shown on the screen at the Saturday night program.

Optical & Mechanical Judging: Things to Know

All amateurs are invited to display their telescopes and to enter them in competitions. Telescopes to be judged for optical and/or mechanical performance must be registered online (below) or at the Registration Table and must be set up one hour before judging begins. Competitors who are registered online must still stop by the Registration Table to pick up their entry forms and identification tags. Please keep the Registration Table folks advised about where your entry is located so that the judges can find you when the time comes.

Registration Table Hours: Friday 5 - 8pm and Saturday 8 – 9:30am
Saturday after 8pm if we are clouded out for Optical on Friday evening
If you are unable to get to the Registration Table during those hours, ask at the Stellafane Pink Clubhouse for Cecilia Detrich, Katie Shusdock or Janet Hunter, and we will find one them to register you individually if possible. Cecilia, Katie and Janet will be at the registration table throughout the convention so you may find them there even beyond the posted hours.

Registration Table Location: In the Stellafane Pink Clubhouse

Telescope Judging Location: (Optical and Mechanical) On the lawns to the North & South of the Stellafane Pink Clubhouse

Optical Judging

Friday 10:00 PM until all scopes have been judged, often extending until 2:00 or 3:00 AM
If Friday is Clouded Out, same times, same place on Saturday.

To be eligible for the Optical Competition, the primary optic must have been made by the exhibitor. Rarely, the chief optical judge may allow another person to represent the actual builder if the person who made the optics can not attend due to a handicap or other reason. These exceptions must be arranged in advance. Small items such as diagonals, prisms, and eyepieces may be purchased.

Your telescope must be in working order so that you can center the eyepiece on Altair or Vega and so that the judges can track by hand or motor when they star test your optics. You should provide an eyepiece with a similar focal length in millimeters as the focal ratio of your telescope (for example, you should use a 5mm eyepiece in an f/5 system). The eyepiece does not need to be exactly correct, but within 1mm is best. This requirement is meant to provide a magnification of about 25 per inch for all apertures and focal ratios.  

Optical Competition Categories:

Judges will examine the telescope for resolution and alignment, assigning numerical scores for the Edge quality, Symmetry of the images (between inside and outside focus, and around the center of the image), Collimation of the telescope, and Contrast of the images. They will examine Vega/Altair in and out of focus and determine if the diffraction ring pattern is symmetrical, and whether the central obstruction (if any) appears centered.

Your telescope should be collimated as well as it can possibly be. If it is not, it will be marked down due to the centering criteria listed above, and this has caused many otherwise excellent telescopes to receive lower scores. Inform the competition registrars if you need assistance collimating your scope - guidance on collimation might be able to be provided.

Be prepared to point your scope at the star Altair when the judges arrive. Please note that the judges may inspect your telescope more than once. Therefore, you should remain on the field with your instrument until the preliminary results are announced via loudspeaker.

If the weather permits the completion of the judging on Friday night, the optical judging will be closed for the duration of the convention and optical awards will be presented during the Saturday evening program. If the optical judging cannot be completed Friday night, it will be continued on Saturday night, weather permitting. Additional optical entries may be accepted on Saturday, at the discretion of the judges. To inquire about this possibility, please ask a judging representative at the table in the Pink Clubhouse from 8:00 a.m. to 9:30 a.m. on Saturday. People are often surprised about how late optical judging can go -plan to stay up with your telescope until 2:00 or 3:00 am.

In the event that the competition will have to be continued Saturday, some telescopes that were judged on Friday might need to be judged again. Please inquire with the registrar if your scope will need to be available again on Saturday. If the optical judging cannot be completed by the end of Saturday night, a partial field of optical excellence awards may be given, at the discretion of the judges.

Please note that it is the intention of the Stellafane judging committee to have the optical competition completed Friday night, weather permitting. Therefore, to ensure that your instrument is judged you must be registered for the Friday night judging.

2017 Optical Judging Chairman: Rick Hunter

Telescope Mechanical Competition
The Heart and Soul of Stellafane!

Saturday 10:00 am – 1:00 pm.

If you have built a telescope, special gadget or restored a historical instrument, we strongly encourage you to bring it and enter it in the competition. We welcome all homemade telescopes in the display area. They do not have to be entered in the competition!

Only telescopes that are operative both mechanically and optically will be accepted in the mechanical competition (with exceptions allowed for the “special” category -see below). The judges may visit the telescopes in several small groups or one larger group. You must attend your telescope until the end of the competition is announced via the loudspeaker. Be prepared to describe any special construction techniques and components to the judges. Awards will be presented at the Saturday evening talks.

To be eligible for the Mechanical Competition, the majority of the instrument must have been made by the exhibitor. Rarely, the chief mechanical judge may allow another person to represent the actual builder if the person who made the entry cannot attend due to a handicap or other reason. These exceptions must be arranged in advance. Small items such as spiders and focusers, etc., may of course be purchased.

To be eligible for the Mechanical Design or Craftsmanship award, a telescope must be operative optically, although not necessarily completed. Telescopes that are not optically operative, or other individual components, may still be entered and will be judged in the Innovative Component, Special Award, or in another category.

For competition in the Mechanical Design category, it is highly recommended that the telescope clearly presents as a complete and finished instrument with at least some history of use validating its design attributes.

Mechanical Competition Categories:

At the discretion of the judges, one or more of the above categories may be dropped, or the number of place awards given reduced, if insufficient quality entrants exist.

For your information, these are the guidelines given to the Mechanical Competition Judges: The following four characteristics are to be examined on each telescope. The specific items to be included in the scoring are listed only as a guideline; judges are encouraged to add others. The craftsmanship score should be based on items 1, 2, and 3. The design score should be based on items 2,3, and 4. A handicap may be deducted from each score depending on how many components were purchased.

  1. Craftsmanship:
    • Parts well machined
    • Castings finished
    • Paint and others finished
    • Non-metal parts well fabricated
  2. Stability:
    • Rigidity
    • Smoothness of bearings
    • Tube vibration
    • Tube balanced in all positions
    • Stays where pointed
  3. Convenience:
    • Ease of setup
    • Tube rotation, if necessary
    • Ease of finder use
    • Smooth focus adjustment
    • Portability/usability
  4. Ingenuity:
    • Unusual solution to component design
    • Use of cheap scrap materials
    • Use of inexpensive tools
    • Easy to build

Note: any numerical scoring is not released to entrants.  This is not to withhold any results but rather simply because scoring is only part of the highly detailed process involved in judging deliberations.

2017 Mechanical Judging Chairman: Chris Houghton

Previous Year's Winners

The 2016 winners of the Optical and Mechanical competition are listed our 2016 Convention Pages here.

Online Telescope Registration

We encourage you to register your scope right here; this will save time for you and us during convention as we can prepare some of the paperwork ahead of time. Thank you. (You must still check in at the judging table before the competition begins so we can mark the location of your instrument on a map for the judges.)

Telescope Registration Form

First Name   Middle Initial   Last Name
City State/Provence   Postal Code
Country     Phone
Email (Required so we can contact you!)
Have you ever been to a Stellafane convention? Yes   No
Have you ever entered an instrument at Stellafane before? Yes   No

I am registering for a First Homemade Telescope Certificate:  Yes   No

I certify the telescope is the first one I have ever made, that I made it substantially myself, and that it is set up on Breezy Hill. (While we encourage you to make your own optics, that is not a requirement for this certificate.)

Even if you are not entering the telescope competition, please fill in the telescope items at the bottom of the Telescope Competition section, so we know what kind of telescope you made.


I am entering: Not Entering, Mechanical Only, Optical Only, Both Mechanical & Optical

Are you entering: Telescope   Other Type of Astronomical Instrument

Entering in the Master Class category:   Yes   No

Entering in the Junior category (under 16 years of age):   Yes   No

Is this an Antique Restoration?  Yes   No

If you are NOT entering a telescope, it should be entered in the mechanical competition. Please provide a description of your non-telescope entry. For antique restorations, provide some history such as maker and year of manufacture:

Your telescope must be optically functional even if you are registering only for the mechanical com­petition! No exceptions. (Rule does not apply for items that are not intended to form an optical image entered in the mechanical competition under the 'Other Instrument' category.)

The instrument's optics must be home made to enter the optical competition (does not include diagonal mirrors).

Please list the materials used in your instrument:

Please list any special components used in your instrument:

Please list any other comments:


Did you make the primary mirror yourself?   Yes   No
Telescope's optical system:  
Telescope's mounting type:  
Aperture of primary objective: inches,   Focal ratio:

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