Welcome to Monocular Guide
Whether you're a birdwatcher seeking a lightweight spotting solution, a hiker wanting to observe distant peaks, or a hunter needing quick target identification, a monocular can be your ideal companion. This guide covers everything you need to know about monoculars, from understanding specifications to choosing the perfect model for your needs.
What is a Monocular?
A monocular is essentially half of a pair of binoculars - a single optical tube that magnifies distant objects. Think of it as a compact, portable telescope designed for handheld use. While binoculars use two optical paths (one for each eye), a monocular uses just one, making it significantly lighter and more compact.
Monocular vs. Binoculars: Key Differences
| Feature | Monocular | Binoculars |
|---|---|---|
| Weight | Very light (typically 100-300g) | Heavier (300-1000g+) |
| Size | Pocket-sized | Bulkier, needs case |
| Depth Perception | Limited (single eye) | Better (both eyes) |
| Eye Fatigue | Can occur with extended use | Less fatigue |
| Price | Generally more affordable | Higher price point |
| Best For | Quick observations, hiking, backup | Extended viewing sessions |
Advantages of Monoculars
- Portability: Fits easily in a pocket or small pouch
- Weight: Perfect for weight-conscious hikers and travelers
- Quick deployment: Faster to pull out and use than binoculars
- One-handed operation: Leaves your other hand free
- Cost-effective: Quality optics at a lower price point
- Smartphone compatible: Many models work with phone adapters for photography
Understanding Monocular Specifications
Monocular specifications can seem confusing at first, but understanding them is crucial for making the right choice. Here's what those numbers mean:
Magnification Power (The First Number)
When you see a monocular labeled "10x42," the first number (10x) is the magnification power. A 10x monocular makes objects appear 10 times closer than they would to the naked eye.
Magnification Recommendations:
- 6x-8x: Great for general use, steady handheld viewing, wider field of view
- 10x-12x: Good balance of power and stability, popular for birdwatching
- 16x-25x: High power for distant subjects, may need tripod for steady viewing
- 40x+: Very high power, definitely requires tripod or stabilization
Objective Lens Diameter (The Second Number)
The second number (42 in "10x42") indicates the diameter of the objective lens in millimeters. Larger lenses gather more light, providing brighter images, especially in low-light conditions.
Objective Lens Guidelines:
- 20-25mm: Ultra-compact, pocket-friendly, best for daytime use
- 32-36mm: Good balance of portability and light gathering
- 42-50mm: Excellent low-light performance, slightly larger
- 50mm+: Maximum brightness, best for dawn/dusk, larger and heavier
Exit Pupil
Exit pupil = Objective lens diameter / Magnification. For example, a 10x42 has an exit pupil of 4.2mm. A larger exit pupil (4-7mm) provides brighter images and is easier to use. In bright daylight, your pupil contracts to about 2-3mm, so exit pupil matters less. In low light, your pupil dilates to 5-7mm, making a larger exit pupil beneficial.
Field of View (FOV)
Field of view indicates how wide an area you can see at a specific distance, typically expressed as feet at 1,000 yards or meters at 1,000 meters. A wider FOV makes it easier to locate and track moving subjects like birds.
Eye Relief
Eye relief is the distance between the eyepiece and your eye where you can see the full field of view. If you wear glasses, look for eye relief of at least 14-15mm, with 17-20mm being ideal.
Close Focus Distance
The minimum distance at which the monocular can focus. Important for observing butterflies, flowers, or insects. Most monoculars focus down to 6-15 feet, while some specialty models can focus as close as 18 inches.
Prism Types
- BAK-4 (Barium Crown): Higher quality, produces sharper images with better edge clarity. Preferred for quality monoculars.
- BK-7 (Borosilicate): More affordable, adequate for casual use but may show slight image softening at edges.
Lens Coatings
- Coated: Single layer on at least one lens surface
- Fully Coated: Single layer on all air-to-glass surfaces
- Multi-Coated: Multiple layers on at least one surface
- Fully Multi-Coated (FMC): Multiple layers on all surfaces - best light transmission and image quality
Monocular Use Cases
Birdwatching
Monoculars are excellent companions for birders who value portability. They're perfect for quick ID of birds in your backyard or on trails where carrying heavy binoculars isn't practical.
Recommended specs: 8x-12x magnification, 32-42mm objective, wide FOV for tracking birds in flight, close focus under 10 feet for nearby subjects.
For serious birdwatching, consider the Gosky 12x55 HD Monocular which offers excellent magnification and a large objective lens for bright, detailed images of distant birds.
Hiking & Backpacking
When every ounce counts, a compact monocular beats binoculars. Use it to scout trails ahead, identify landmarks, observe wildlife, or simply enjoy distant vistas.
Recommended specs: 8x-10x magnification, 25-36mm objective for balance of performance and portability, waterproof rating, rubber armor for durability.
The Vortex Optics Solo 10x36 is a top choice among hikers for its rugged build, excellent optics, and included utility clip for easy access.
Hunting
Hunters use monoculars for game spotting and range estimation. The quick one-handed operation is valuable when you need to keep your other hand on your firearm or bow.
Recommended specs: 10x-12x magnification, 42-50mm objective for dawn/dusk viewing, waterproof and fogproof, durable construction.
For low-light hunting conditions, the Gosky Titan 12x50 provides excellent light gathering with its 50mm objective lens.
Stargazing & Astronomy
While not a replacement for a proper telescope, monoculars can reveal lunar craters, Jupiter's moons, and star clusters. They're great for casual sky watching and meteor showers.
Recommended specs: Higher magnification (12x+), large objective (50mm+), tripod adaptable for steady viewing.
Sports & Events
A compact monocular fits easily in your pocket for concerts, sporting events, or theater performances where binoculars might be too bulky.
Recommended specs: 8x-10x magnification, compact size (25-32mm objective), quick focus system.
Night Vision Applications
Digital night vision monoculars use infrared illuminators and sensors to see in complete darkness. These are popular for wildlife observation, security, and nighttime hunting (where legal).
Recommended specs: IR illuminator with adjustable levels, good battery life, recording capability for documentation.
The Sheawasy Night Vision Monocular offers 1080P recording, a 32GB memory card, and 7 IR levels for complete darkness viewing.
Monocular Buying Guide
Follow this guide to find the perfect monocular for your needs and budget.
Step 1: Determine Your Primary Use
Your main activity dictates the ideal specifications:
- General/casual use: 8x25 to 10x32 - compact and versatile
- Birdwatching: 10x42 to 12x50 - balance of power and brightness
- Hiking/travel: 8x25 to 10x36 - prioritize compactness and weight
- Hunting: 10x42 to 12x50 - low-light performance matters
- Night observation: Digital night vision with IR illuminator
Step 2: Set Your Budget
Budget ($20-50)
Basic optics, BK-7 prisms, single coating. Suitable for occasional casual use. Image quality acceptable but not impressive.
Mid-Range ($50-150)
BAK-4 prisms, multi-coated or FMC lenses, waterproof construction. Good image quality for regular use. Best value for most users.
Premium ($150-400)
High-quality ED (extra-low dispersion) glass, superior coatings, excellent build quality. Sharp, bright images with minimal chromatic aberration.
Professional ($400+)
Top-tier optics from renowned manufacturers. Best possible image quality, lifetime warranties, exceptional durability.
Step 3: Check Essential Features
- Waterproof rating: Look for IPX7 or better for outdoor use
- Fogproof: Nitrogen or argon purged to prevent internal fogging
- Rubber armor: Protects from drops and provides grip
- Tripod mount: Essential for high magnification or extended viewing
- Smartphone adapter: Useful for digiscoping (photography through the monocular)
Step 4: Consider Ergonomics
- Focus wheel: Should be smooth and easy to reach
- Eye cup: Twist-up or fold-down for glasses wearers
- Size and grip: Should feel comfortable in your hand
- Weight: Light enough for your intended use
Top Monocular Recommendations
Based on specifications, user reviews, and value for money, here are our top monocular picks for different categories:
Best Overall Value
Gosky 12x55 HD Monocular
- Magnification: 12x
- Objective Lens: 55mm
- Prism: BAK-4
- Coating: Fully Multi-Coated
- Field of View: 352ft/1000yds
The Gosky 12x55 delivers impressive performance at a reasonable price. The large 55mm objective provides bright images even in lower light conditions, while the BAK-4 prism and FMC lenses ensure sharp, clear views. Includes a smartphone adapter for photography.
Check Price on AmazonBest for Hiking
Vortex Optics Solo 10x36
- Magnification: 10x
- Objective Lens: 36mm
- Prism: Roof prism
- Waterproof: Yes (O-ring sealed)
- Includes: Utility clip
Vortex is known for quality optics, and the Solo delivers. The included utility clip makes it instantly accessible from a pack strap or belt. Waterproof, fogproof, and built to handle trail abuse. Vortex's VIP warranty covers it unconditionally.
Check Price on AmazonBest for Low Light
Gosky Titan 12x50
- Magnification: 12x
- Objective Lens: 50mm
- Prism: BAK-4
- Coating: Fully Multi-Coated
- Waterproof: Yes
The Titan's 50mm objective paired with quality BAK-4 prisms makes it excellent for dawn and dusk observation. Great for hunters and wildlife watchers who need to see clearly in challenging light. Includes smartphone holder and tripod adapter.
Check Price on AmazonBest Budget Option
16x52 High Power Monocular
- Magnification: 16x
- Objective Lens: 52mm
- Prism: BAK-4
- Field of View: 66m/8000m
- Waterproof: Yes
An affordable entry point with surprisingly good performance. The 16x magnification is powerful enough for most applications, though a steady hand or tripod helps at this power level. Good for beginners testing the waters.
Check Price on AmazonBest Compact
10x40 Compact Monocular
- Magnification: 10x
- Objective Lens: 40mm
- Design: Non-slip grip
- Best for: Camping, hiking
- Focus: Quick-focus system
A solid compact choice that balances portability with performance. The 10x magnification is manageable for handheld use while the 40mm objective provides adequate brightness. Non-slip design works well in various conditions.
Check Price on AmazonBest Night Vision
Sheawasy Night Vision Monocular
- Type: Digital infrared
- Resolution: 1080P FHD
- IR Levels: 7 adjustable
- Storage: 32GB included
- Viewing: Day and night
See in complete darkness with this digital night vision monocular. The 850nm IR illuminator with 7 intensity levels lets you observe wildlife without disturbing them. Records photos and video to the included 32GB card.
Check Price on AmazonBest with Smartphone Mount
12x60 Monocular with Tripod
- Magnification: 12x
- Objective Lens: 60mm
- Includes: Phone holder, tripod
- Best for: Photography
- Coating: FMC
The large 60mm objective and included smartphone holder make this ideal for digiscoping. Capture photos and video of distant subjects through your phone. The included tripod provides stability for the higher magnification.
Check Price on AmazonStylish Choice
Nocs Provisions Zoom Tube 8x32
- Magnification: 8x
- Objective Lens: 32mm
- Prism: BAK4
- Design: Premium styling
- Build: Durable aluminum
Nocs brings style to the monocular world without sacrificing performance. The 8x32 configuration is perfect for everyday carry, and the BAK4 prism delivers crisp images. A favorite among design-conscious outdoor enthusiasts.
Check Price on AmazonMonocular Care & Maintenance
Proper care extends the life of your monocular and maintains optical performance.
Cleaning the Lenses
- Remove loose debris: Use a soft brush or compressed air to remove dust and particles before wiping
- Use proper cleaning solution: Apply lens cleaning solution to a microfiber cloth, not directly to the lens
- Wipe gently: Use circular motions from the center outward
- Dry properly: Use a dry portion of the cloth to remove any remaining moisture
- Avoid: Paper towels, tissues, shirt fabric, or household glass cleaners - these can scratch coatings
Storage Tips
- Store in a dry place with lens caps in place
- Use the included case or pouch for protection
- Avoid extreme temperatures (hot cars, freezing conditions for extended periods)
- Add silica gel packets to storage area to absorb moisture
- Store with the objective lens facing down to prevent dust settling on the eyepiece
Field Care
- Use the neck strap or wrist lanyard to prevent drops
- Keep lens caps handy for quick protection
- Avoid touching lenses with fingers (oils degrade coatings over time)
- If the monocular gets wet, dry it before storage but don't use heat
- In cold weather, let the monocular acclimate before moving between temperature extremes
What to Avoid
- Never disassemble your monocular - this voids warranties and risks misalignment
- Don't look at the sun through your monocular - it can cause eye damage
- Avoid using alcohol-based cleaners on rubber armor
- Don't force the focus wheel if it becomes stiff - this indicates a need for service
Frequently Asked Questions
Is a monocular better than binoculars?
Neither is objectively better - they serve different needs. Monoculars excel in portability, one-handed use, and weight savings. Binoculars provide more comfortable extended viewing, better depth perception, and are generally easier on the eyes for long observation sessions. Many outdoor enthusiasts own both.
What magnification is best for general use?
8x to 10x is ideal for most people. This range offers good magnification while remaining stable enough for handheld use. Higher magnification (12x+) amplifies hand shake and often requires a tripod or support.
Can I use a monocular for stargazing?
Yes, especially for casual astronomy. Monoculars can reveal lunar craters, Jupiter's moons, Saturn's rings (as an oval shape), and many star clusters and nebulae. For serious astronomy, a proper telescope is better, but a monocular is a great portable option.
Are expensive monoculars worth it?
It depends on your usage. For casual use, a mid-range monocular ($50-150) offers excellent value. Premium models provide noticeably better image quality, especially in edge sharpness, color accuracy, and low-light performance. Professionals and serious enthusiasts will appreciate the difference.
Can I attach my phone to a monocular?
Many monoculars include smartphone adapters or are compatible with universal phone mounts. This allows you to take photos and videos through the monocular (called digiscoping). Look for models with a flat eyepiece design for the best phone compatibility.
What does "waterproof" actually mean?
Waterproof ratings vary. IPX4 handles splashes, IPX7 survives submersion to 1 meter for 30 minutes, and IPX8 handles deeper/longer submersion. For outdoor use, IPX7 or better is recommended. Note that "water-resistant" is not the same as waterproof.
Why is my view through the monocular shaky?
Higher magnification amplifies hand movement. Try bracing your elbows against your body, leaning against a stable surface, or using a tripod. Monoculars above 10x typically benefit from some form of stabilization for the steadiest view.
Monocular Terminology Glossary
- BAK-4
- Barium crown glass used in high-quality prisms; provides sharper images and better edge clarity than BK-7.
- BK-7
- Borosilicate glass used in prisms; more affordable but may show slight image quality reduction at edges.
- Chromatic Aberration
- Color fringing around high-contrast edges, caused by different wavelengths of light focusing at different points. ED glass reduces this effect.
- Diopter
- Adjustment that compensates for differences between your eyes; important in binoculars, not applicable to monoculars.
- ED Glass
- Extra-low dispersion glass that reduces chromatic aberration for sharper, more color-accurate images.
- Exit Pupil
- The diameter of the light beam leaving the eyepiece; calculated as objective lens diameter divided by magnification.
- Eye Relief
- The distance from the eyepiece where you can see the full field of view; important for eyeglass wearers.
- FMC (Fully Multi-Coated)
- Multiple anti-reflective coatings on all air-to-glass surfaces; provides maximum light transmission.
- FOV (Field of View)
- The width of the area visible through the optic, usually expressed as feet at 1,000 yards.
- Nitrogen/Argon Purged
- Inert gas filling that prevents internal fogging when moving between temperature extremes.
- Objective Lens
- The front lens that gathers light; larger diameter means brighter images but increased size and weight.
- Porro Prism
- A prism design with an offset light path; often found in larger, traditional-style optics.
- Roof Prism
- A compact prism design allowing for a straight-through barrel; used in most modern compact monoculars.