magnifying glass
Enable an agent to recognise a magnifying glass, assess whether it can provide a useful enlarged view, and choose appropriate handling, positioning and care.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a magnifying glass, assess whether it can provide a useful enlarged view, and choose appropriate handling, positioning and care.
A magnifying glass is a direct-view optical instrument using a converging lens or lens assembly to present an enlarged, upright virtual image of a nearby object, increasing its apparent angular size.
It can be Position the lens, object and eye to obtain an upright enlarged view.; Compare candidate magnifiers using documented magnification, usable field and working distance.; Adjust a support or integrated light to improve visibility and stability.; Inspect and clean the lens using methods compatible with its material and coatings.; Withdraw a damaged or unstable unit from use pending repair or replacement.; Cover or store the lens to prevent unintended concentration of sunlight..
Distinguishing features
Provides a direct enlarged view through a positive-power lens assembly without requiring a camera or display.
In its ordinary magnifying configuration, a nearby object produces an upright virtual image viewed through the lens.
Does not require the separate objective and eyepiece arrangement characteristic of a compound microscope.
Its primary task is enlargement of nearby detail, rather than correction of the wearer's vision or observation of distant objects.
A loose positive lens is included only when its intended role is use as a direct-view magnifier; optical power alone does not establish tool identity.
Scope
+ Handheld and supported magnifying glasses used for direct visual inspection
+ Lens assemblies and their optical performance in the intended viewing configuration
+ Frames, handles, stands and integrated illumination that support magnified viewing
+ Object, lens and eye positioning needed to obtain a useful enlarged view
+ Optical condition, cleaning, storage and sunlight-related precautions
- Compound microscopes and their objective-eyepiece imaging systems
- Telescopes and binoculars intended primarily for distant objects
- Electronic magnifiers whose enlarged image is presented on a display
- Spectacles and clinical assessment or prescription of vision correction
- The identity, composition or diagnosis of the specimen being inspected
Characteristics
- Lens construction
- Single lens; compound lens assembly; Fresnel lens; other documented construction; unknown Construction affects image quality, thickness, weight and suitable cleaning methods.
- Effective focal length
- mm, with measurement method or specification source Helps establish the viewing geometry and interpret magnification claims.
- Stated angular magnification
- Dimensionless ratio expressed as ×, with reference viewing distance and viewing convention Magnification labels are not reliably comparable without their assumed viewing conditions.
- Clear aperture
- mm diameter, or mm width × height for noncircular apertures Constrains the viewing opening but does not alone determine the usable field.
- Usable object field
- mm diameter or width × height, with object distance, eye position and image-quality criterion Shows how much of the inspected surface can be viewed usefully at once.
- Object-side working distance
- mm from a stated lens or housing reference surface to the object Determines whether the tool leaves enough clearance for the inspection task.
- Support configuration
- Handheld; fixed stand; adjustable stand; folding support; other Determines how viewing distance is maintained and whether hands remain available.
- Illumination provision
- Ambient only; integrated unpowered light guide; integrated powered lighting; other Separates passive magnification from optional features that introduce power and maintenance needs.
- Optical and mechanical condition
- Record contamination, scratches, cracks, haze, loose lens retention and support instability separately Different defects require different responses and can affect both visibility and handling.
- Task compatibility
- Links to intended detail size, inspected surface, access constraints and viewing requirements Suitability depends on the inspection task rather than nominal magnification alone.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 14 findings · 23 questions.
Magnifier identity Establishes which direct-view magnifying tools the registry entry represents.
A magnifying glass can resemble a loose lens, loupe, microscope component or electronic magnifier, so recognition needs an explicit optical and functional boundary.
Direct-view function
Identifies the enlargement task and the optical path used to perform it.
Near-detail enlargement
Record whether the tool is intended to enlarge nearby detail for an eye looking directly through its lens assembly.
- Is the enlarged view seen directly through the lens, or supplied by a camera and display? boundary
- What nearby detail is the tool intended to make easier to distinguish? definition
Construction and kind boundary
Separates variants of the tool from neighbouring optical instruments and particular products.
Lens assembly and support
Describe the lens assembly and its support without treating one manufacturer, lens material or handle shape as the definition of the kind.
- What lens construction and support arrangement does this variant use? definition
- Does it function as a simple direct-view magnifier or as part of a separate objective-eyepiece instrument? boundary
Optical performance Describes the enlargement and useful view available under stated viewing conditions.
Nominal magnification alone cannot establish whether the tool will reveal the required detail.
Magnification and focus
Connects focal properties and magnification claims to their assumptions.
Interpretable magnification
Keep stated magnification distinct from measured performance and record the convention behind the stated value.
- What angular magnification is specified, and what reference distance and eye-focus condition does that value assume? provenance
- What effective focal length is documented or measured, and by what method? measurement
Field and image quality
Captures how much detail remains useful across the visible region.
Usable detail across field
Assess usable field and detail visibility together, including edge blur, distortion, colour fringes and glare where observed.
- What object area remains acceptably clear at the recorded object distance and eye position? measurement
- Which observed image defects prevent the intended detail from being distinguished? measurement
Viewing setup Relates lens placement, support and lighting to a practical inspection task.
A serviceable magnifier can still fail its task when clearance, steadiness or illumination is unsuitable.
Eye, lens and object geometry
Records the distances and support needed to maintain the desired view.
Stable working position
Establish an achievable viewing position with enough clearance and stability for the task.
- At what lens-to-object and eye-to-lens distances is the required upright enlarged view obtained? measurement
- Can the handle or support maintain that position while leaving the required access to the object? action
Inspection lighting
Describes illumination of the object and optional powered lighting features.
Light without obscuring detail
Record whether illumination exposes the detail or obscures it through reflections, glare or shadows, and identify controls only where present.
- Which light position and setting make the target detail visible without obstructive glare or shadow? action
- If lighting is integrated, what power source, controls and replaceable components are documented? provenance
Condition, care and storage Determines whether the lens and support remain usable and how they should be maintained and stored.
Lens damage degrades the view, failed retention creates handling hazards, and an exposed positive lens can concentrate sunlight.
Lens and support condition
Distinguishes removable contamination from optical damage and mechanical faults.
Inspect before intervention
Record the location and effect of defects before choosing cleaning, repair or withdrawal from use.
- Are visibility problems caused by removable contamination, scratches, cracks, haze or another observed defect? measurement
- Does the frame retain the lens securely, and does the support hold its viewing position? measurement
- Given the observed defects, should the unit be cleaned, repaired or withdrawn from use? action
Compatible care and sunlight control
Links cleaning to lens materials and storage to the possibility of focused sunlight.
Protect surfaces and surroundings
Use documented material-compatible care and prevent the stored lens from concentrating direct sunlight onto people or nearby materials.
- Which cleaning agents and methods are supported for the documented lens material and coatings? provenance
- What cover or storage position prevents direct sunlight from passing through the lens and being concentrated onto nearby surfaces? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The sense covered is the optical instrument class, not a specific product or the graphical search icon.
- Size and magnification ranges are approximate recall values, not specification limits; magnification claims require checking their reference viewing distance.
- Ordinary unilluminated magnifiers are passive; illuminated versions require electrical power, and applicable product requirements depend on their construction and market.
- Which of these check these first hold for the sense of magnifying glass this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Handheld magnifier
- Stand magnifier
- Illuminated magnifier
- Folding pocket magnifier
- Fresnel sheet magnifier
- Inspection loupe
- Which of these kinds and varieties hold for the sense of magnifying glass this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Enlarging print and other close visual tasks
- Inspecting small components, surface defects and workmanship
- Examining stamps, coins, jewellery and other collectibles
- Observing insects, plants and geological specimens
- Demonstrating refraction, focal length and image formation
- Which of these real-world use hold for the sense of magnifying glass this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Nominal angular magnification - Approximately 2-10 for common handheld magnifiers; rating depends on the viewing convention - ×
- Lens diameter - Approximately 20-100 for common handheld circular magnifiers - mm
- Which of these typical measurements hold for the sense of magnifying glass this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Scratches, dirt and coating damage reduce contrast and visibility.
- Spherical and chromatic aberration can blur or colour image edges, especially in simple lenses.
- Incorrect object distance prevents the intended upright magnified view.
- Concentrated sunlight can burn skin or ignite combustible material; viewing the sun through the instrument can cause severe eye injury.
- Broken glass, loose lens mounts or damaged handles can cause injury or make the instrument unusable.
- Which of these failure modes and hazards hold for the sense of magnifying glass this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Converging lens - A converging lens is an optical component; a magnifying glass is an instrument using that component or a lens assembly for direct visual enlargement.
- Compound microscope - A compound microscope uses an objective to form an intermediate image that an eyepiece magnifies; a magnifying glass operates as a simple magnifier.
- Loupe - A loupe is generally a compact, close-working magnifier and overlaps this category rather than forming a wholly separate class.
- Reading glasses - Reading glasses provide near-vision correction while worn before the eyes; a magnifying glass is positioned to enlarge the apparent view of a target.
- Digital magnifier - A digital magnifier enlarges a camera image on a display rather than providing direct optical viewing through a magnifying lens.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of magnifying glass this model covers, and on what evidence? provenance
What the second pass must settle
- Does the wider registry place loupes, sheet magnifiers and wearable magnifiers within this entry or in separate registered kinds?
- Which authoritative optical terminology and magnification conventions should govern comparison of manufacturer claims?
- Which standards, issuing bodies and conformity requirements apply to passive magnifiers and to variants with integrated electrical lighting in the intended markets?
- What sourced ranges of magnification, clear aperture and working distance represent common variants without implying universal limits?
- Which documented inspection criteria distinguish tolerable cosmetic defects from damage requiring withdrawal for each lens material and support design?