Binoculars Usage Guide

Binoculars are an excellent tool for astronomy, offering wide fields of view and ease of use. They’re perfect for beginners and experienced observers alike, providing wonderful views of star clusters, the Moon, and even some nebulae and galaxies.

CUAS Binoculars

CUAS has several pairs of binoculars available for member use:

• 10×50 binoculars (standard astronomical binoculars)
• 15×70 binoculars (larger aperture for deeper sky viewing)
• 20×80 binoculars (may require tripod mounting)

The numbers indicate magnification × aperture in millimetres. For example, 10×50 means 10x magnification with 50mm objective lenses.

Getting Started

Understanding Binocular Parts

• Objective Lenses: The large lenses at the front
• Eyepieces: Where you look through
• Focus Wheel: Central wheel that adjusts focus
• Diopter Adjustment: Usually on right eyepiece, compensates for differences between your eyes
• Hinge: Adjusts interpupillary distance (distance between your eyes)

Basic Setup

1. Adjust the Interpupillary Distance:

   • Hold binoculars up to your eyes
   • Adjust the hinge until you see a single circular field of view

2. Focus Adjustment:

   • Cover the right objective lens or close your right eye
   • Look at a distant object and adjust the centre focus wheel until sharp with your left eye
   • Cover the left objective lens or close your left eye
   • Adjust the diopter ring (usually on right eyepiece) until sharp with your right eye
   • Now both eyes should be in focus when using the centre wheel

3. Stabilisation:

   • For 10×50 binoculars: Brace elbows against your body or lean against a stable object
   • For larger binoculars: Consider using a tripod with a binocular adapter
   • Alternatively, lie on your back on a reclining chair for extended viewing comfort

Astronomical Observing with Binoculars

What to Observe

• The Moon: Excellent target showing craters, maria (dark areas), and mountain ranges
• Star Clusters:
  • Open clusters: Pleiades, Hyades, Double Cluster in Perseus
  • Globular clusters: M13 in Hercules, M3, M5
• Bright Nebulae: Orion Nebula (M42), Lagoon Nebula (M8)
• Galaxies: Andromeda Galaxy (M31), Bode’s Galaxy (M81) and Cigar Galaxy (M82)
• Milky Way: Scanning the Milky Way reveals countless stars and dark dust lanes
• Meteor Showers: Wide field of view is perfect for catching meteors

Observing Techniques

• Star Hopping: Use bright stars to navigate to fainter objects
• Scanning: Slowly sweep across areas of interest
• Averted Vision: Look slightly to the side of faint objects to use more sensitive peripheral vision
• Steady Hands: Keep as still as possible for stable views

Care and Maintenance

• Keep Lens Caps On: When not in use
• Proper Storage: Store in case in a dry place
• Cleaning:
  • Blow off dust with air blower
  • If needed, use lens cloth or lens tissue with proper cleaning solution
  • Never directly apply cleaning fluid to lenses
  • Clean in circular motions from centre outward
• Avoid Touching Lenses: Fingerprints are difficult to clean
• Temperature Acclimation: Allow binoculars to adjust to outside temperature before use

Using Binoculars with Tripods

For larger binoculars or extended viewing sessions:

1. Use a binocular tripod adapter (L-shaped bracket)
2. Attach adapter to binoculars and then to tripod
3. Balance weight properly to prevent strain on mount
4. Consider a fluid head for smooth movements
5. A reclining chair can work well for casual observing without a tripod

Tips for Better Viewing

• Allow 20-30 minutes for your eyes to dark adapt
• Use a red light to preserve night vision
• Observe from a dark location away from direct lights
• Learn key constellations to help navigation
• Consider a star chart app (with night mode) for identifying targets
• Start with easy targets before moving to more challenging ones
• Schedule observing around the Moon phases (new moon for deep sky, first quarter for lunar observing)

Borrowing CUAS Binoculars

To borrow CUAS binoculars:

1. Contact the ObsSecs at cuasobserv@gmail.com
2. Arrange pickup and return dates
3. Sign out the equipment in the logbook
4. Return in the same condition as borrowed

For any questions about using binoculars for astronomy, contact the CUAS Observation Secretaries at cuasobserv@gmail.com