Celestron C5 Spotting Scope Instruction Manual

Model #52291

A spotting scope is a telescope designed for terrestrial viewing, producing correctly oriented images. Celestron spotting scopes utilize high-quality optics and rugged housings for durability and minimal maintenance. This manual provides instructions for the Celestron C5 spotting scope, covering its setup, operation, and care.

Important Safety Information

• Never look directly at the Sun with the naked eye or with the spotting scope. Permanent eye damage can result.
• Never use the spotting scope to project an image of the Sun onto any surface, as internal heat buildup can damage the equipment.
• Never use an eyepiece solar filter or Herschel wedge without proper precautions, as internal heat can cause them to crack or break, allowing unfiltered sunlight through.
• Never leave the spotting scope unsupervised, especially when children are present.
• Always use a proper solar filter when pointing the spotting scope at the Sun. Celestron solar filters are recommended.
• Always cover the finderscope when using a solar filter, as it can also cause permanent eye damage and burns.

Assembly

The Celestron C5 spotting scope uses a Schmidt-Cassegrain optical system, a compact and rugged design combining mirrors and lenses.

Included Accessories:

• 25 mm Plössl Eyepiece (50x magnification)
• 6x30 Erect Image Finderscope
• 45° Erect Image Diagonal (1.25")
• Photo Tripod Adapter block
• Nylon Water Resistant Case
• Lens Cap

The Erect Image Diagonal

The diagonal prism diverts light at a right angle. To attach it:

1. Loosen the thumbscrew on the visual back.
2. Slide the diagonal into the visual back.
3. Tighten the thumbscrew to secure it.

The orientation of the diagonal can be adjusted by loosening and retightening the thumbscrew.

The Eyepiece

The eyepiece magnifies the image. To install an eyepiece:

1. Loosen the thumbscrew on the diagonal.
2. Slide the eyepiece into the diagonal.
3. Tighten the thumbscrew.

Eyepieces are identified by focal length (determines magnification) and barrel diameter (1-1/4" for the C5). Longer focal length equals lower power; shorter focal length equals higher power.

Finderscope

The 6x30 erect image finder helps locate objects. To attach it:

1. Unthread the three screws in the finder bracket.
2. Slide the rubber O-ring onto the eyepiece end of the finder.
3. Position the O-ring towards the objective end of the finder.
4. Slide the finder into the front ring of the bracket until the O-ring is snug.
5. Hand tighten the three set screws.

Alignment of the finder is described in the "Aligning the Finder" section.

Attaching to a Tripod

The C5 attaches to a photographic tripod using a 1/4" x 20 threaded screw via the included photo tripod adapter block. Align one of the block's holes with the tripod screw and tighten to secure the spotting scope.

Technical Information

• Aperture: 5" (125 mm)
• Focal Length: 1250 mm (f/10)
• Optical System: Schmidt-Cassegrain
• Resolution: 0.9 arc sec.
• Tube Length: 11"
• Weight (with mount): 6 pounds
• Finderscope: 6x30
• Highest Useful Magnification: 300x
• Lowest Useful Magnification: 23x
• Limiting Magnitude (visual): 13
• Near Focus: Approximately 20'
• Angular Field of View (standard eyepiece): 1.04°
• Angular Field of View (with Reducer/Corrector): 1.7°
• Coatings: Starbright XLT

Focusing

The focusing mechanism moves the primary mirror. The focusing knob is located on the rear cell. Turn the knob until the image is sharp. If the knob won't turn, the mirror has reached its limit. Turn clockwise for closer objects and counterclockwise for distant objects. Approximately 40 turns are needed to go from close focus to infinity.

Calculating Magnification

Magnification = (Focal Length of Spotting Scope) / (Focal Length of Eyepiece)

Example: Using a 25 mm eyepiece with the C5 (1250 mm focal length) yields 50x magnification (1250 / 25 = 50).

The highest useful magnification is generally 60x per inch of aperture (300x for the C5). Most observing is done between 20x-35x per inch (100x-175x for the C5).

Determining Field of View

True Field = (Apparent Field of Eyepiece) / Magnification

Example: With a 25 mm eyepiece (52° apparent field) and 50x magnification, the true field is 1.04° (52 / 50 = 1.04).

To convert degrees to feet at 1,000 yards: multiply by 52.5. (1.04° x 52.5 = 54.6 feet).

Observing Tips

• Never look through window glass, as optical imperfections can affect focus.
• Avoid looking across or over heat-producing objects like asphalt on hot days.
• Hazy skies, fog, and mist can reduce detail and affect focus.
• When using the C5 as a telephoto lens with an SLR camera, use the ground glass focusing screen or a focusing magnifier if the viewfinder "blacks out."
• For visual observation, remove eyeglasses. For photography, wear eyeglasses for sharpest focus. Wear eyeglasses if you have astigmatism.

Photography

The C5 can be used for terrestrial and astronomical photography. Use through-the-lens metering to set exposure. Use a cable release to minimize vibration when tripping the shutter for sharper photos.

Care & Maintenance

• Cleaning the Corrector Plate: Remove dust with a brush or compressed air. Use an optical cleaning solution and soft tissue, wiping from the center outwards. Do not rub in circles. A solution of 60% isopropyl alcohol and 40% distilled water, or diluted liquid dish soap, can be used.
• Dew Prevention: Use a Celestron Lens Shade / Dew Cap or point the scope at the ground until dew evaporates.
• Internal Moisture: If moisture condenses inside, place the scope in a dust-free environment, point it down, and remove accessories to allow evaporation.
• Prevent Contamination: Replace lens covers when not in use, especially the rear cell opening.
• Internal Cleaning/Adjustments: Should only be performed by Celestron's repair department. Contact them for return authorization.

SOLAR WARNING

Never attempt to view the Sun without a proper solar filter. Permanent eye damage and equipment damage can occur.

For assistance, contact Celestron Technical Support at celestron.com/pages/technical-support.

© 2024 Celestron. Celestron and Symbol are trademarks of Celestron, LLC. All rights reserved. Celestron.com

2835 Columbia Street, Torrance, CA 90503 USA

This product is designed and intended for use by those 14 years of age and older.

Made in China • 07-24