COMMISSIONING YOUR OWN
Made to Order
Questar 3.5" telescopes are Made to Order with delivery times measured in weeks to months, depending on current production queue and parts inventory. When choosing to purchase a Questar 3.5", you can work with either Questar directly or an authorized reseller to help customize your purchase with the right selection of options. Some of the options are purely cosmetic such as the use of a genuine leather case rather than an equally functional case made of vinyl (more popularly called "vegan leather" nowadays). Other options are fundamental to the optical performance or user experience. One benefit of working with an authorized reseller is the ease of adding 3rd-party accessories to your Questar or flexible payment plans.
Several different models are available and both the Questar Standard and Duplex come fully functional with no additional accessories required to get started. Two eyepieces are included to provide six different real-world magnifications when accounting for the barlow and finder modes. Common 3rd-party accessories can include additional eyepieces and high-performance scientific cameras that can help you take photographs of the planets and the moon and attach directly to a laptop/desktop.
Astronomics.com is one of the largest on-line retailers of astronomy equipment and also own and operate CloudyNights.com, the largest online community of astronomy enthusiasts. Astronomics allows you to purchase Questar products from the convenience of your web browser, which is particularly important if you're making your purchase outside of routine business hours.
Many enthusiasts choose to purchase from Company Seven. Company Seven's expertise with Questar products is unparalleled given their expertise across the entire Questar product line including the scientific and reconnaissance products. Company Seven is an ideal choice for those local to Montepelier, Maryland. However, they typically work primarily via in-person visits and telephone rather than an online interface or email, which can be a benefit for the improved communication or an obstacle depending on your time zone and schedule.
It is also possible to order directly from Questar as well.
These prices were accurate as of 2020.
STEP 1: SELECT YOUR MODEL
Specialized Questar 3.5" optical assemblies are available for scientific and industrial use. For the consumer line, there are four options.
The Standard
The Standard represents the original Questar design for the home astronomy hobbyist. The optical assembly and mount are a single integrated unit.
Visually, this is the most elegant design with a circumferential star chart and economy of design.
Starting Price: $5,150
The Duplex
The Duplex is a modular design that allows the optical tube of the telescope to be separated from the base/mount. Total weight is higher, but it is now possible to carry each component individually and to use the optical tube assembly itself on a regular camera or video tripod.
Starting Price: $5,500
Field / Birder
The Field and Birder only provide a optical assembly and the customer must provide the mount. For astronomical use, it is essential to have a dedicated astronomy mount or a camera tripod with a geared head. These do not come with the Star Chart/Moon map standard.
The Birder adds a supplemental lens to the finder for increased magnification and a re-geared focus knob for an additional $680.
Starting Price: $3,495
STEP 2: SELECT YOUR OPTICS
All Questar optics provide excellent quality, but various upgrades are available for specific needs. If in doubt, be confident that the entry-level configuration has stood the test of time.
Pyrex / MgF2
ALUMINUM
The base configuration is built around a Pyrex mirror coated with aluminum and a corrector using traditional magnesium fluoride anti-reflection coatings. The Pyrex used in astronomical telescopes is true borosilicate glass opposed to the modern "Pyrex food storage" which is heat-strengthened soda-lime glass.
No-Cost Option
Pyrex / BBAR
SILVER
The Pyrex mirror is now coated with silver, which is a more reflective material than aluminum and the use of "broadband" dielectric anti-reflective coatings increase effective total light grasp by 22%.
Continuous exposure to salt may damage the optics (i.e. coastal homes).
+ $375 Upgrade
Zerodur/BBAR
SILVER
Schott Zerodur is used instead of Pyrex. Zerodur is a low-expansion substrate and maintains its shape across a wide ranger of temperatures than Pyrex glass. Thermal cool down of the telescope of the system is slightly better in very cold environments. The air in the telescope still needs to come to equilibrium.
Continuous exposure to salt may damage the optics (i.e. coastal homes).
+ $725 Upgrade
Quartz / MgF2
ENHANCED ALUMINUM
1/10 wave precision
Fused silica (Quartz) offers some of the thermal benefits of Zerodur though its thermal performance is not quite as good.
Enhanced aluminum is used for the mirror which offers some of the reflectivity benefits of silver while maintaining resiliency in coastal environments.
Instruments commissioned with Quartz optics also are guaranteed to reach 1/10 wave precision at the focal point taking the optics even closer to the mathematical limits of performance based upon the physics of light.
+ $1695 upgrade
Quartz / MgF2
SILVER
1/10 wave precision
For the 50th Anniversary Edition, Questar offered a specialized model with the combination of Quartz mirror substrate and a silver mirror.
Only 250 units were made.
No longer available
STEP 3: SELECT YOUR MOTOR
One of the toughest choices when commissioning your instrument is the motor.
The Questar 3.5" is not designed as a computerized "Go-To" mount. Thus, in its most basic configuration, you change the altitude/azimuth of the telescope by manually turning high-precision knobs to point the telescope toward your target. As the planets and moon travel on their orbits, and the Earth rotates around its axis, your target slowly drifts out of view requiring you to manually correct the position of the telescope.
After aligning your Questar 3.5" to the Celestial North Pole which is close to Polaris (the North Star), your Questar 3.5" can rotate along this axis to follow the movement of the night sky. This stabilizes the image in the eyepiece and can improve the details that are viewable in very stable atmospheric conditions.
Synchronous Electric Drive
110V AC household power
Once polar aligned, plugging in your Questar to a standard household outlet engages the synchronous electric drive to rotate the telescope to approximate the rotation of the night sky. Slight variations in the frequency of your home current will result in slight variations in tracking speed. This variability is typically not an issue unless attempting sophisticated long-exposure imaging.
Aftermarket portable AC inverters provide an untethered battery-powered option, however variations in frequency still apply and modified-sine wave may have different results than true-sine wave.
No cost option
PowerGuide III
9V battery power
The synchronous motor is replaced a high precision stepper motor that is powered by a battery powered handheld controller. The option of AC power is lost.
The tracking rate is carefully calibrated to a quartz-reference clock and it is possible to track at the rate of the Earth's rotation (for viewing the planets and night sky) or at the slightly different rate of the combination of the Moon's orbit and Earth's rotation.
This option offers a lightweight portable unit. Battery life is about 6 hours on a 9V battery. Aftermarket rechargeable batteries are highly recommended.
The now-discontinued PowerGuide II used a simple controller with extended battery life, but the components for the PowerGuide II can no longer be sourced. The current PowerGuide III uses a monochrome LCD touchscreen. The touchscreen is durable across wide ranges of temperature, but is bulkier. Future software upgrades to the hand controller are planned.
+ $649 upgrade