# Lamps: research notes Date: 2026-10-21. Scope: portable luminaires for the home that plug in or run on a battery: table lamps, bedside lamps, desk and task lamps, floor lamps (including torchieres and arc lamps) and rechargeable cordless lamps. Not ceiling fixtures, wall sconces or bare bulbs, except where a bulb's spec becomes the lamp's because the bulb is included. In the Zamana taxonomy socket lamps sit under furnishings / decor (`lighting_fixture_lamp`, `lamp_shade_base`) and built-in LED lamps under machines / electronics (`led_lighting`); the register keeps one facet set and lets the `light_source` split route between them. Quote labels: **verbatim** = the sentence in quotation marks was in text I read myself (pdftotext on a downloaded PDF, or curl plus HTML stripping) or the fetch tool returned it in quotation marks; **fetched excerpt** = the fetch tool summarised or lightly reworded the page; **search excerpt** = the claim came from a search-engine summary because the page itself would not load. A search-excerpt-only number does not go in category.json. ## Seed Seed run (recorded verbatim from the brief): - Example: car-tyres `treadwear_grade`: "a number that is on every listing and still needs a judgement attached, because experts know it only compares within one manufacturer's range." - Persona: "A car mechanic, who thinks in wear, serviceability and what fails first." 1. **The lamps equivalent of treadwear is the rated life of a built-in LED, the "25,000 hours" or "lasts 17 years" line.** It is on every integrated-LED listing and it is real, but it measures the wrong thing. It is L70, the projected hours until the LED chip fades to 70 percent, produced by running the chip for 6,000 hours (LM-80) and extrapolating by at most six times (TM-21). It says nothing about the driver, the electronics that actually fail. The DOE's 2009 reliability sheet says such claims "do not account for other components or failure modes" (verbatim); the NGLIA 2014 lifetime guide's field chart puts 73 percent of failures in the driver power supply, 1 percent in driver controls and 7 percent in the LED packages (figures read off the rendered chart, with the guide's own caveat that the chart "cannot be generalized across all types of products"). Like treadwear, the number is comparable in principle (L70 is a defined metric) but useless as a ranking of how long the lamp will work. **Kept** as `rated_life_h` with a judgement attached and `warranty_years` as the number to read instead. ENERGY STAR turns out to encode exactly this: 3-year warranty where the driver is replaceable, 5 years where it is not (verbatim). 2. **The mechanic notices serviceability first: can you change the part that fails?** That is the socket-versus-integrated split, and it survives as split 2 (`light_source`) with the strongest data in the register. The mechanic would also check: the switch (what wears), the cord (does it reach), the base (does it tip; UL 153's 15 degree stability test, verbatim), and whether the dimmer will fight the bulb (leading-edge dimmers and LED drivers; verbatim from Jolt Electric). **Kept**: `switch_type`, `cord_length_m`, `safety_listing`, the dimmer compatibility note inside `dimmable`. **Dropped**: a "heat inside a closed glass shade shortens LED bulb life" facet. The claim is widely made (search excerpts from 1000bulbs and Tecolite; one verbatim line from Luxeon Star that enclosing a driver "traps heat"), but neither consumer page could be fetched and I have no second verified source with a number, so it stays here as a note. ## Sources and what each supports ### Regulators and standards bodies **FTC consumer leaflet "An important message from the Federal Trade Commission: What to look for" (govinfo PDF, pdftotext)** https://www.govinfo.gov/content/pkg/GOVPUB-FT-PURL-gpo25713/pdf/GOVPUB-FT-PURL-gpo25713.pdf - verbatim chart "How Bright a Light?": "150 w 2600 lm / 100 w 1600 lm / 75 w 1100 lm / 60 w 800 lm / 40 w 450 lm", "Estimates based on typical incandescent bulbs". - verbatim: "lumens = brightness / watts = energy"; "A standard 60-watt incandescent bulb, for example, produces about 800 lumens of light." - verbatim label contents: "Brightness (in lumens) / Yearly estimated energy cost / Expected bulb life (in years) / Light appearance (how warm or cool the light will look) / Wattage (the energy used) / If the bulb contains mercury". - verbatim sample label: "Estimated Yearly Energy Cost $7.23 Based on 3 hrs/day, 11¢/kWh"; "Light Appearance Warm Cool 2700 K"; "Energy Used 60 watts". - Supports: the lumens ladder, the Kelvin scale as a visual grammar, the energy-cost derived metric. Confidence high. **FTC, Shopping for Light Bulbs (consumer.ftc.gov)** https://consumer.ftc.gov/articles/shopping-light-bulbs - fetched excerpt (quoted): "a traditional 60-watt incandescent bulb produces about 800 lumens of light"; label shows "brightness (in lumens)", "yearly estimated energy cost", "expected bulb life (in years)", "light appearance (how warm or cool the light will look)". - Supports: second source for 60 W = 800 lm and label contents. Confidence high. **16 CFR 305.23 Labeling for lighting products (Cornell LII)** https://www.law.cornell.edu/cfr/text/16/305.23 - fetched excerpt (quoted): energy cost "based on the average initial wattage, a usage rate of 3 hours per day and 11 cents ($0.11) per kWh"; life "expressed in years rounded to the nearest tenth (based on 3 hours operation per day)"; light appearance "placed proportionately on the scale where the left end equals 2,600 K and the right end equals 6,600 K". - Supports: the energy-cost formula and the 2,600 to 6,600 K scale endpoints. Confidence high. **ENERGY STAR, Learn about brightness** https://www.energystar.gov/products/lighting_fans/light_bulbs/learn_about_brightness - fetched excerpt: 40 W "450", 60 W "800", 75 W "1,100", 100 W "1,600" lumens. - Supports: second source for the lumens ladder. Confidence high. **ENERGY STAR Program Requirements for Luminaires, Eligibility Criteria Version 2.2 (PDF, pdftotext)** https://www.energystar.gov/sites/default/files/Luminaires%20V2.2%20Final%20Specification.pdf - verbatim definitions: "Floor Lamp (Luminaire): a portable luminaire on a high stand, suitable for standing on the floor. (ANSI/IES RP-16-17)"; "Table Lamp (Luminaire): A portable luminaire with a short stand suitable for standing on furniture."; "Torchiere or Torchère (Luminaire): An indirect floor lamp that sends all or nearly all of its light upward."; "Portable Desk Task Light (Luminaire): A light fixture resting on a desk that directs light to a specific surface or area". - verbatim scope: "Portable Desk Task Lights" under directional luminaires; "Portable" under non-directional. - verbatim 9.4 CRI: solid state "shall be capable of meeting or exceeding Ra ≥ 80 and R9 > 0." - verbatim table (section 9, efficacy): "Portable Desk Task 50 lm/W Luminaire shall deliver a minimum of 200 lumens. Luminaire shall deliver a minimum of 60% of total lumens within the 0-75° zone"; "Inseparable Other SSL Luminaire 70 lm/W Luminaire shall deliver a minimum of 200 lumens." - verbatim 10: "L70(6k) ≥ 25,000 hours" for indoor; "≥ 25,000 hours for indoor luminaires / ≥ 35,000 hours for outdoor luminaires / ≥ 50,000 hours for inseparable luminaires". An inseparable luminaire is one whose LEDs and driver "cannot be easily removed or replaced by the end user, thus requiring replacement of the entire luminaire", which is what this register calls a built-in LED lamp. - verbatim 11.7 Flicker: "The following flicker-related metrics shall be reported for certifications as of September 1, 2018: Short Term Flicker Indicator (Pst), Stroboscopic Visibility Measure (SVM)"; method "NEMA 77-2017"; "Optional: meet NEMA 77-2017 for temporal light modulation limits." - verbatim 12.1: LED light engines "shall make use of electrical interconnects that allow for consumer replacement of the engine or kit without the cutting of wires or the use of solder"; luminaires that cannot "are to be evaluated as inseparable SSL luminaires". - verbatim 15.1 Dimming: "shall provide continuous dimming from 100% to 20% of light output. At minimum light output, the luminaire shall not emit noise above 24 dBA when measured within one meter of the luminaire." - verbatim 17 Warranty: solid state with replaceable drivers "a minimum of 3 years from the date of purchase"; "For luminaires incorporating non-replaceable drivers, the above warranty requirement is extended to 5 years."; "Warranty language shall place no limitations on coverage based on duration of luminaire operation (e.g. hours per day)." - Supports: the trade's definitions of lamp types, the CRI floor, the L70 floor, dimming behaviour, flicker reporting, the 3 versus 5 year warranty, the efficacy floors. Confidence high. (An earlier fetch-tool summary of this PDF claimed "Minimum CRI 90, R9 50, percent flicker 10%"; the text does not say that. Only the pdftotext figures above are used.) **UL 153, Standard for Portable Electric Luminaires, 2025 preview (PDF, pdftotext)** https://ulnormdoc.com/wp-content/preview/UL%20153%202025.pdf - verbatim 1.1: "These requirements cover portable luminaires and subassemblies whose primary function is task or ambient illumination."; 1.2: "intended for connection to a nominal 120-volt, 15- or 20-ampere branch circuit, by means of an attachment plug". - verbatim 2.58: "TORCHIERE – A portable luminaire supported by the floor having a bowl shaped shade with the concave surface facing upward (open top/closed bottom design) intended to provide indirect light. ... The lamp (bulb) is typically 5 – 6 feet (1.27 – 1.52 m) above the floor". - verbatim 18.2: "The portable luminaire shall not overturn when tested in accordance with the Stability Test, Section 153, with a 15 degree inclined plane." - verbatim 20A.4.1: "If the portable luminaire has a user-replaceable light source, the user instructions shall provide guidance for acquiring a suitable replacement light source. This is in addition to the lamp replacement markings of Sections 201 – 205". - Not in the preview text: the temperature-test wording about the maximum marked lamp wattage (a search excerpt said the lamp is run "with a lamp rated 500 watts or the maximum wattage lamp of the same type specified in the lamp replacement marking"). Not used in the JSON. - Supports: the stability test, the torchiere definition, the lamp replacement marking, the scope. Confidence high. **CPSC, 1997 corrective action on halogen torchiere floor lamps** https://www.cpsc.gov/Recalls/1997/CPSC-and-Industry-Announce-Corrective-Action-to-Improve-Safety-of-Halogen-Torchiere-Floor-Lamps - fetched excerpt (quoted): "40 million halogen torchiere floor lamps"; "at least 189 fires and 11 deaths since 1992"; "only halogen bulbs of 300 watts or less in the lamp"; "free-standing lamps with a shallow bowl-shaped light fixture mounted on top of a 6-foot pole". - Supports: why heat ratings and listings matter; torchiere description. Confidence high. **IEEE Std 1789-2015, Recommended Practices for Modulating Current in High-Brightness LEDs (PDF, pdftotext)** https://www.lisungroup.com/wp-content/uploads/2020/02/IEEE-2015-STANDARDS-1789-Standard-Free-Download.pdf - verbatim: "Modulation (%) = 100 × (Lmax – Lmin)/(Lmax + Lmin)". - verbatim Recommended Practice 1: "Between 90 Hz and 1250 Hz, Modulation (%) is below 0.08×frequency. Above 1250 Hz, there is no restriction on Modulation (%)." - verbatim Recommended Practice 2 (NOEL): "Between 90 Hz and 3000 Hz, Modulation (%) is below 0.0333×frequency. Above 3000 Hz, there is no restriction on Modulation (%)." - verbatim NOTE: "When PWM dimming is used, the percent flicker is 100%." - verbatim: the low-risk line "corresponds to a factor of about 2.5 above the NOEL". - Supports: the flicker thresholds and the flicker map grammar. Confidence high. **LightingEurope, FAQ on alleged LED related health issues, December 2016 (PDF, pdftotext)** https://www.lightingeurope.org/images/publications/general/FAQ_on_alleged_LED_related_health_issues_-_December_2016.pdf - verbatim: "A luminaire employing a light source classified RG0 or RG1 requires no warning or caution."; "general illumination products used in homes, offices, stores, and schools do not produce intense levels of blue light"; on flicker: "Current standards, however, do not define maximum permissible levels of these effects." - Supports: the eye-care judgement; that flicker has no mandatory limit. Confidence high (industry body; paired with ICNIRP below). **ICNIRP Statement on LEDs, 2020 (PDF, pdftotext)** https://www.icnirp.org/cms/upload/publications/ICNIRPled2020.pdf - verbatim: "Acute damage to the human retina from typical exposure to blue or white LEDs has not been demonstrated."; "Thus far, the only clear, acute adverse health effects from LEDs are those due to temporal light modulation (including flicker). Glare can also create visual disturbances when LED light fixtures are not properly designed." - Supports: the eye-care judgement and the priority of flicker over blue light. Confidence high. **LEDVANCE, FAQ on EU regulations 2019/2020 (SLR) and 2019/2015 (ELR) (PDF, pdftotext)** https://www.ledvance.com/00_Free_To_Use/asset-13016798_slr-elr_faq_en.pdf - verbatim: "Luminaires, as containing product, will no longer require an energy label as early as December 25, 2019. As a light source, luminaires must be labeled as of September 1, 2021."; "A++ to E will become A to G." - Supports: EU listings show an energy class only for bulbs and for lamps whose LED cannot be removed; not for socket lamps. Confidence medium (manufacturer FAQ; the Commission FAQ page returned 403). ### LED life and failure **US DOE, LED Measurement Series: LED Luminaire Reliability (2009 fact sheet, PDF, pdftotext)** https://cool.culturalheritage.org/byorg/us-doe/luminaire_reliability.pdf - verbatim: life claims "are based on the estimated lumen depreciation of the LED used in the product and often do not account for other components or failure modes. Life claims by LED luminaire manufacturers should take into account the whole system, not just the LEDs." - verbatim: "The LM-80 test procedure addresses only one factor in the life of an LED luminaire – lumen depreciation of the LED device over the prescribed test period."; other factors include "failure of the driver or other electrical components". - Supports: rated life is lumen fade only. Confidence high. **Next Generation Lighting Industry Alliance / LED Systems Reliability Consortium, LED Luminaire Lifetime: Recommendations for Testing and Reporting, September 2014 (PDF, pdftotext)** https://www.nglia.org/pdfs/led_luminaire_lifetime_guide_sept2014.pdf - Figure 5 (page 21, rendered with pdftoppm and read as an image, because pdftotext scrambles the pie labels), "SSL Luminaire - Failure by Category (as % of All Failures across 212M Field Operating hours)": Driver (Power Supply) 73%, Housing Integrity 17%, LED Packages 7%, Electrical Contact 2%, Driver (Controls) 1%. Source: Appalachian Lighting Systems, Inc. - verbatim caveat: "Figure 5 below, an updated version of that chart, cannot be generalized across all types of products"; it is an outdoor family and "housing integrity ... generally would not apply to indoor or less-exposed products". - verbatim: members' "Most-Observed LED System Failures" chart is led by "Power/driver components". - Supports: the driver fails first; the 74 percent figure (73 + 1) and the 7 percent LED figure, with the caveat. Confidence high for the figure, medium for generalising it to table lamps (which is why the register says "one luminaire family"). **Wikipedia, Lumen maintenance** https://en.wikipedia.org/wiki/Lumen_maintenance - fetched excerpt (quoted): L70 is "the expected operating hours until light output has diminished to 70% of initial levels"; "LM-80 specifies a minimum testing period of 6,000 hours, with 10,000 hours being the preferred testing period." - Supports: L70 and LM-80 definitions. Confidence high. **Hyperlite, LM-80 vs TM-21** https://hi-hyperlite.com/blogs/comprehensive-guides/lm80-tm21-testing-lifetime-projection-led - fetched excerpt (quoted): "a lifetime projection cannot exceed six times (6x) the actual test duration of the LM-80 data"; 6,000 h test → 36,000 h maximum; 10,000 h → 60,000 h. - Supports: the six-times cap. Confidence medium (vendor explainer), paired with the next source. **OlamLED, In-depth analysis of LED lifetime standards** https://www.olamled.com/in-depth-analysis-of-led-lifetime-standards-lm79-lm80-tm21-and-l-value-definitions/ - fetched excerpt (quoted): "With 20 or more samples, a projection may extend to six times the test duration; with 10 to 19 samples, 5.5 times."; "LM-80 applies to the LED package, so it tells you nothing about the optic, the driver or the heat path inside the luminaire." - Supports: second source for the cap; that LM-80 says nothing about the driver. Confidence medium. **Portfolio Lighting, Integrated LED vs socketed LED lifespan data** https://www.portfoliolighting.net/database/integrated-led-vs-socketed-lifespan-data.html - fetched excerpt (quoted, attributed by the page to a USPTO filing): "While an LED chip has a potential lifetime of over 100,000 hours, the average lifetime of an LED driver is around 20,000 to 30,000 hours"; (attributed to Eaton) "More often than not, the point of failure is the driver."; the capacitor rule "Every 10°C increase ... the expected service life approximately halves". - Supports: background for the driver argument. Confidence low to medium (secondary compilation); not used for any number in the JSON. **Moonlight Design, Everything you need to know about integrated LED lights (curl)** https://www.moonlightdesign.co.uk/blogs/blog/everything-you-need-to-know-about-integrated-led-lights - verbatim: "the answer to the question, 'Can an integrated LED be replaced?' is usually no."; "In most cases, you must replace the entire integrated LED light fixture if it breaks or reaches end-of-life."; "They typically operate between 20,000 and 50,000 hours". - Supports: the consumer consequence of the integrated choice. Confidence medium (retailer). **Upgraded Home, Can an integrated LED light bulb be replaced?** https://upgradedhome.com/can-an-integrated-led-light-bulb-be-replaced/ - fetched excerpt (quoted): "Integrated LED light bulbs cannot be replaced because they are built into the circuitry."; "You must replace the entire fixture if an integrated LED light bulb goes bad." - Supports: second consumer source. Confidence medium. ### Flicker, colour and light quality **Waveform Lighting, Diagnosing and resolving LED flicker issues** https://www.waveformlighting.com/human-centric/diagnosing-and-resolving-led-flicker-issues - fetched excerpt (quoted): "Most LED bulbs flicker at 100-120 Hz. At this frequency, the IEEE 1789 recommended safe ('low risk') flicker percentage is 8%, and 3% to completely eliminate the effects of flicker."; "many PWM dimmers use a frequency that is too low"; most dimmers "will not include a PWM frequency specification"; phone "SLO-MO" camera test. - Supports: plain-language flicker thresholds, the phone test, that specs are missing. Confidence high (consistent with the IEEE text). **Waveform Lighting, Does color rendering matter? 80 CRI vs 90 CRI vs 95 CRI** https://www.waveformlighting.com/home-residential/does-color-rendering-matter-80-cri-vs-90-cri-vs-95-cri - fetched excerpt (quoted): CRI uses "eight standardized colors"; at 80 CRI "nuanced colors, especially those that have a deep red component will appear unnatural"; at 90 "skin tones ... will for the most part appear normal"; at 95 "nearly identical to their appearance under natural light"; R9: the body says "around 0", "around 50" and "around 90" for 80, 90 and 95 CRI while the page's summary says "25, 50 and 90" (the checker read both); the register says roughly 0 to 25 at 80 CRI; "higher CRI is almost always associated with lower efficiency"; "higher purchase cost". - Supports: the CRI facet and the CRI-versus-efficiency trade-off. Confidence medium-high (a high-CRI vendor, but the claims match ENERGY STAR's R9 > 0 floor and Golden Lighting below). **Golden Lighting, What is CRI in lighting? 80 vs 90+** https://goldenlighting.com/blogs/the-golden-edit/what-is-color-rendering-index-in-lighting-2 - fetched excerpt (quoted): "CRI 80 to 89: Rooms look decent, but some materials still lack depth"; "CRI 90 to 94: Better skin tones, truer paint, richer woods and fabrics"; R9 is "saturated red, which drives skin and wood tones"; "Use 90+ CRI where people spend time up close". - Supports: where CRI 90 matters. Confidence medium. **Fotios, A Revised Kruithof Graph Based on Empirical Data, LEUKOS 2017 (White Rose eprint PDF, pdftotext)** https://eprints.whiterose.ac.uk/id/eprint/98531/17/Fotios_2017_a_new_Kruithof_graph.pdf - verbatim abstract: "these do not support Kruithof. For pleasant conditions, these data suggest only avoiding low illuminances and do not favor any CCT." - verbatim conclusion: "1. Variation in CCT has a negligible effect on ratings of brightness and pleasantness. 2. Low illuminances (less than approximately 300 lux) may be perceived as unpleasant; an illuminance of 500 lux is sufficient to provide a pleasant environment and a further increase in illuminance above 500 lux is of little benefit."; "nine of the 29 studies presented credible evidence". - Supports: the Kruithof judgement; the 300 to 500 lux anchor; the colour-temperature-is-taste judgement. Confidence high. **Feit Electric, Light color temperature guide** https://www.feit.com/blogs/inspire/how-to-choose-the-right-color-light-temperature-for-your-bulb-or-fixture - fetched excerpt: 2700K soft white "Bedroom, Living Room, Dining Room"; 3000K "Bathroom, Hallway, Accent Lighting"; 3500K "Kitchen, Home Office, Laundry Room"; 4000K "Bathroom Vanity, Kitchen, Workspace"; 5000K "Garage, Basement, Security Lighting". - Supports: the retail room convention. Confidence medium. **Pro Lighting, Choosing the right color temperature for your home** https://www.prolighting.com/blog/2020/06/16/choosing-the-right-color-temperature-for-your-home/ - fetched excerpt (quoted): bedroom "2700-3000K"; living room "2700-3000K"; kitchen "3000K–4000K"; home office "3000-5000K". - Supports: second source for the room convention. Confidence medium. **US DOE SSL, Understanding LED color-tunable products** https://www.energy.gov/eere/ssl/understanding-led-color-tunable-products - fetched excerpt (quoted): dim-to-warm products "mimic incandescent or halogen dimming performance, usually designed for 2700-3000K at full output with a decrease in correlated color temperature (CCT) as the output is reduced, down to as low as 1800K"; white-tunable uses warm "around 2700K" and cool "5000K to 6500K" sets. - Supports: dim-to-warm and tunable definitions. Confidence high. **Bees Lighting, Dim to warm vs tunable white** https://www.beeslighting.com/blogs/ideas-advice-blog/dim-to-warm-vs-tunable-white-led - fetched excerpt (quoted): "shift from a crisp 3000K down to an amber 1800K"; "dual-chip architecture"; needs "a modern Electronic Low Voltage (ELV) or TRIAC dimmer switch that is specifically rated for LED loads". - Supports: second source for dim-to-warm. Confidence medium. **Jolt Electric, Your guide to LED bulb dimmer compatibility** https://www.joltelectric.biz/post/your-guide-to-led-bulb-dimmer-compatibility - fetched excerpt (quoted): leading-edge dimmers cut "power at the very beginning of each electrical wave, doing this 120 times every second"; "The sensitive electronics in an LED driver interpret this choppy signal as faulty power"; result "flickering, buzzing, strobing"; the 10 percent rule: "a 600W dimmer can probably only handle about 60W worth of LEDs"; use the maker's "compatibility list". - Supports: the dimmer-compatibility note. Confidence medium (electrician's blog; consistent with ENERGY STAR's NEMA SSL 7A reference). **Wikipedia, 3-way lamp** https://en.wikipedia.org/wiki/3-way_lamp - fetched excerpt (quoted): "A 3-way lamp, also known as a tri-light, is a lamp that uses a 3-way light bulb to produce three levels of light in a low-medium-high configuration."; "One common 3-way incandescent bulb is the 50/100/150 W."; GE announced it in 1933. - Supports: 3-way definition; it is a North American convention. Confidence high. **Cary Lighting, 3-way light bulb base guide** https://www.carylighting.com/info/3-way-light-bulb-base-guide-103552602.html - fetched excerpt (quoted): "A 3-way bulb usually runs at one brightness in an ordinary on/off socket."; 3-way LED bulbs exist and "list three lumen outputs". - Supports: second source. Confidence medium. **Gearbrain, How to use a smart light bulb: light switch must be left on** https://www.gearbrain.com/how-smart-light-bulb-works-1801637028.html - fetched excerpt (quoted): "A smart bulb must always have power flowing to it to perform its smart functions."; "If you use the lamp or a wall switch to turn off the light, Voila, the bulb ceases being smart." - Supports: the smart-bulb caveat in `switch_type` and the smart trade-off. Confidence high. **Hue Home Lighting, Can you still use your existing light switches with Hue?** https://huehomelighting.com/can-still-use-existing-light-switches-hue/ - fetched excerpt (quoted): Hue bulbs "must always be switched on at the mains"; after a switch-off and on, the bulb returns to "a bright warm white glow. This state is the default on state". - Supports: second source. Confidence medium (enthusiast site). **ERCO, SDCM (color consistency)** and **Any-lamp, What is the MacAdam ellipse?** (fetched excerpts: "From SDCM = 4, differences are clearly recognized"; "3 SDCM: Few deviations visible"; "5 SDCM: Strongly visible deviations"). Considered for a colour-consistency facet for pairs of lamps. Dropped from the register (see "Dropped"); kept here. ### Sizing rules (retailers and designers) **Lamps Plus, How to buy a table lamp** https://www.lampsplus.com/ideas-and-advice/how-to-buy-a-table-lamp/ - fetched excerpt (quoted): "the bottom of the shade should line up with your eye level so that the light isn't shining directly into your eyes"; bedside: "the bottom of the lamp shade should line up around chin level"; "Buy a table lamp with a shade that is smaller than the width of the table". - Supports: the eye-level rule and its reason (glare). Confidence high for the rule as a trade convention. **Lamps Plus, How to size a lamp shade** https://www.lampsplus.com/ideas-and-advice/how-to-size-a-lamp-shade/ - fetched excerpt (quoted): "your lamp shade should be roughly one-third the height of the lamp body. For some tall and modern lamp designs, the shade may be up to one-half the height."; "shade's width be roughly equivalent to the visible height of the lamp base"; "the lamp shade is wider than the widest part of your lamp body"; four measurements: top diameter, bottom diameter, slant, height. - Supports: shade proportion rules. Confidence medium (one convention among several). **Lamps Plus, How to measure a lamp shade and select the right fitting (curl)** https://www.lampsplus.com/ideas-and-advice/how-to-measure-a-lamp-shade/ - verbatim: "Spider fittings are the most common type of fitting for table and floor lamps and are used with harps."; "Uno Fittings are used on smaller table lamps, bedside lamps, and swing-arm lamps. No harp is needed as an Uno fitting attaches directly to the lamp socket."; "Clip-on fittings are found on small accent lamps and chandeliers. The wire fitting simply clips directly onto the light bulb." - Supports: fitter definitions. Confidence high. **Fenchel Shades, Can you put a lamp shade on any lamp?** https://www.fenchelshades.com/blog/post/can-you-put-a-lamp-shade-on-any-lamp-a-complete-guide - fetched excerpt (quoted): "The height of the shade should be roughly one-third the height of the total lamp."; "The width of the lampshade should be twice the width of the lamp base."; spider, uno, clip-on and slip-uno fittings. - Supports: the 2x width and one-third height rules. Confidence medium. **Kevin Francis Design, Measure first, avoid returns: lamp shade sizes** https://kevinfrancisdesign.com/blogs/design-ideas/lamp-shade-sizes - fetched excerpt (quoted): "bottom diameter should run 1.5 to 2 times the width of the base"; "Shade height should be approximately 60 to 70 percent of the lamp's body height"; floor lamps "closer to one-third of total lamp height"; "the shade bottom sit roughly at or slightly below eye level when you're seated"; "Measure the harp, not just the socket." - Supports: the alternative proportion rule (the disagreement) and the harp note. Confidence medium. **Masdio, Bedside table lamp height** https://masdio.com/blogs/news/bedside-table-lamp-height - fetched excerpt (quoted): "the ideal bedside table lamp height typically ranges between 24 to 30 inches"; "the total height (table + lamp) should usually land between 58 and 64 inches from the floor"; "the bottom of the lampshade should sit at or slightly below eye level when you're seated in bed". - Supports: bedside height band and the combined height band. Confidence medium (retailer). **Tablelights, How to choose the right lamp size (curl)** https://tablelights.com/blogs/post/lamp-size-style-guide - verbatim: "When you are sitting on a sofa or chair, the bottom of the lamp shade should be at your eye level."; "Living Room: Most table lamps should be between 24 and 34 inches tall."; "Bedside: Your lamp should generally be 26 to 30 inches tall"; "If the base is 6 inches wide, the shade should be at least 12 inches wide."; "Aim for that 58 to 64 inch sweet spot."; "a lamp height of 28 to 32 inches on a standard side table works best for most readers." - Supports: second source for 58 to 64 in combined, the 24 to 34 in table lamp band and the 2x shade width. Confidence medium. **The Everything Depot, Table lamp size guide** https://theeverythingdepot.com/table-lamp-size-guide/ - fetched excerpt (quoted): "18 inches" from tabletop to seated eyes (attributed to a Lamps Plus example); standard table lamps "24 to 32 inches"; desk/task lamps "15 to 27 inches"; shade "about one third of the overall lamp height" and "wider than the widest part of the base"; "60 watts or more" for reading; "around 2700 to 3000 Kelvin"; "design rules of thumb, not fixed standards". - Supports: height bands and the honest caveat. Confidence medium. **Eyely, What height should your new floor lamp be?** https://www.eyely.com/blogs/lighting/whats-the-right-height-for-a-floor-lamp - fetched excerpt (quoted): "When it comes to floor lamps, they should be 58 to 64 inches tall."; "The bottom of the lamp shade should not be lower than the eye level of a seated person." - Supports: floor lamp band. Confidence medium. **Govee, How tall should a floor lamp be? (curl)** https://us.govee.com/blogs/smart-lamps/how-tall-should-a-floor-lamp-be - verbatim: "Most floor lamps fall somewhere between 58 and 64 inches (about 147–163 cm)"; reading: "just about shoulder height when you're seated"; living room: "bottom of the shade is positioned just above eye level when you're seated, which usually happens to fall around 60–66 inches total height"; task: "the shade should be slightly above your seated eye level (50–58 inches)". - Supports: second source for 58 to 64 in; the shoulder rule for reading floor lamps. Confidence medium (brand blog). **Golden Lighting, How tall should your lamp be?** https://goldenlighting.com/blogs/the-golden-edit/how-tall-should-your-lamp-be-sizing-it-to-the-furniture - fetched excerpt (quoted): "These are house design guidelines based on common design conventions, not independently verified industry standards"; table lamps: shade bottom at seated eye level; floor lamps: shade bottom "at or slightly above the shoulder line of someone seated". - Supports: the rules are conventions; the floor-lamp shoulder rule. Confidence medium. ### Light distribution and shades **AGi32 Photometric Toolbox docs, IES Indoor Report Summary** https://docs.agi32.com/PhotometricToolbox/Content/Indoor_Report_Tool/IES_Indoor_Report_Summary.htm - fetched excerpt (table): Direct 0–10% up / 90–100% down; Semi-Direct 10–40 / 60–90; General Diffuse 40–60 / 40–60; Semi-Indirect 60–90 / 10–40; Indirect 90–100 / 0–10. - Supports: the CIE classification. Confidence high. **Manufacturer.lighting, Types of light distribution for indoor luminaires** https://www.manufacturer.lighting/club/15/ - fetched excerpt (quoted): direct luminaires "distribute 90 to 100 percent of the emitted light in the general direction of the surface to be illuminated"; semi-direct "60 to 90 percent ... downward"; general diffuse "40 to 60 percent ... downward"; semi-indirect "60 to 90 percent ... upward"; indirect "90 to 100 percent ... upward". - Supports: second source for the bands. Confidence medium. **Color Cord Company, Shades 101** https://www.colorcord.com/blogs/lighting-design-blog/shades-101-understanding-shade-materials-types-of-light-shades - fetched excerpt (quoted): "Translucent hues on a lightweight material (glass or fabric) to provide powerful light from every angle."; "Dark hues on a dense material (metal or natural) to project light from the top and bottom of a shade."; "an opaque metal shade delivers the best results" for directional light; fabric "a happy medium of diffusion between glass and metal". - Supports: mapping shade material to distribution. Confidence medium. **Pooky, A guide to lampshade fabrics** https://www.pooky.com/blogs/inspiration/a-guide-to-lampshade-fabrics - fetched excerpt (quoted): velvet shades "are opaque and don't transmit light around the space as much as some other materials, but instead they send the light upwards and downwards, creating a lovely pool of light underneath"; linen "diffuses a lovely ambient light". - Supports: second source for the opaque-versus-translucent split. Confidence medium. ### Bulb bases and wattage **Bright Ideas Lighting, Bulb base guide** https://brightideaslighting.store/blogs/news/bulb-base-compatibility-guide - fetched excerpt (quoted): E26 "26 mm", E27 "27 mm", E12 "12 mm", E14 "14 mm"; B22 "Standard in the UK, Australia and India"; "An E26 bulb screws into an E27 socket and vice versa"; "a bulb rated only for 220–240 V will run dim or not at all on 120 V"; E12/E14 "not interchangeable". - Supports: base codes and regions. Confidence medium. **Glowryte, Light bulb base guide** https://glowryte.com/blogs/lighting-guides/light-bulb-base-guide - fetched excerpt (quoted): "E26 is the most common bulb base in the United States. It is the standard medium screw base used in many residential light fixtures, including table lamps, floor lamps"; "E12 is the candelabra base ... 12 millimeters"; "E27 is the standard European medium base". - Supports: second source. Confidence medium. **SlashGear, Can you use a 100W LED bulb in a 60W socket?** https://www.slashgear.com/1819588/60w-socket-100w-led-bulb-compatibility-explained/ - fetched excerpt (quoted): a 100 W-equivalent LED "only uses between 12 and 14 watts on average, with some coming closer to 20 watts"; check that "the wattage of your bulb — the actual wattage used, not the incandescent equivalent measurement — doesn't exceed that of the fixture". - Supports: max wattage is a heat rating on actual watts. Confidence medium; the FTC chart supplies the 1,600 lm side. ### Specialist reviewers and spec sheets **Wirecutter, Our favorite bedside lamps (read via a mirror at ideal.house that credits The New York Times; nytimes.com cannot be fetched)** https://ideal.house/community/news/our-8-favorite-bedside-lamps-of-2026-reviews-by-wirecutter - fetched excerpt (quoted criteria): "ease of use (in-line switch, pull chain, or touch control, or smart bulb compatibility)", "effective light diffusion through a well-designed shade", "a stable base to prevent tipping", "a minimum 5-foot cord length", "dimmable functionality", "compatibility with common, accessible bulbs". - Supports: bedside criteria, the 5 ft cord floor, dimming as a requirement. Confidence medium (mirror; the criteria list is specific enough to trust, the numbers are not load-bearing beyond the cord). **Wirecutter, The best desk lamp** (search excerpt only; nytimes.com blocked): tested lux at lowest and highest height settings; panel of 23 staff; "CRI ... 90 or above"; a lamp dropped after "flickering during video calls". Not used for any number. **DeskForged, Best desk lamps** https://deskforged.com/rankings/best-desk-lamps/ - fetched excerpt (quoted): "I used an ambient light meter at 12 points across a 140cm desk surface and measured evenness, peak lux, and falloff at the edges."; flicker checked with "a phone slow-motion camera at 240fps"; CRI values quoted: BenQ ScreenBar Halo 2 Ra95+, Lepro Ra85, Dyson Solarcycle Morph Ra90+; "A desk lamp exists to put photons on your workspace without wrecking your eyes or washing out your screen." - Supports: how task lamps get tested. Confidence medium (independent blog). **BenQ, e-Reading desk lamp product page** https://www.benq.com/en-us/lighting/e-reading-desk-lamp/e-reading.html - fetched excerpt (quoted): "Ra 95"; e-Reading mode "500lux at a color temperature of 4000k"; paper-reading mode "1000lux of illumination directly below"; "35.4"" wide coverage; "2700K" to "5700K"; "non-flicker driver chip" and "passed the IEEE 1789 standard for LED luminaires"; "max.18W"; "up to 17 years, 8 hours per day". - Supports: what a premium task lamp specifies; the "17 years" life marketing. Confidence high for what the page says. **The Lightie, Dyson Lightcycle Morph review** https://thelightie.com/reviews/dyson-lightcycle-morph - fetched excerpt (quoted): "850 lumens"; "CRI 90 minimum"; "less than 1% flicker under the cited test condition"; "2700–6500K"; "We have not independently measured output, colour quality, flicker, glare, or dimming behaviour." - Supports: published figures for a second premium task lamp. Confidence medium (document-researched review). **Flos, Bellhop Table / Unplugged product page** https://flos.com/en/us/bellhop-table/M-bellhop.html - fetched excerpt (quoted): "Power (W): 3"; "CCT (K): 2700"; "Charging min. time: 3H"; "IP rating: 20"; "Dimmable: Yes"; battery autonomy "up to 24 hours". No lumens on the page (retailers quote 151 lm, search excerpt only). - Supports: cordless power, runtime, IP. Confidence high for the stated fields. **Lightology, Zafferano Poldina Pro listing** https://www.lightology.com/index.php?module=prod_detail&prod_id=983136 - fetched excerpt (quoted): "1 x LED/2.2W"; "256 lumens" at 3000K ("234-251-256 lumens" across 2200/2700/3000K); "80 CRI"; "9 hours" battery (description also says "12 hour battery life"); "6 hours" charge; "IP65 rating"; "built-in 0 to 100% dimmer". - Supports: the one fetched cordless lumen figure, IP65, runtime. Confidence high for the listing's figures. **Heal's, HAY PC Portable listing** https://www.heals.com/pc-portable-outdoor-table-lamp.html - fetched excerpt (quoted): "Wattage: 3.5W"; "Lumens: 1000-1500lm"; "Colour temperature kelvins: 2700-3000K"; "Battery life: 10 Hours"; "Charging time: 8 Hours"; "Ip rating: IP44: Splash-proof". - The lumen figure is not credible for a 3.5 W LED (search excerpts from Connox and Galaxus give 220 lm). Used for wattage, runtime and IP only; the lumen disagreement is logged as a judgement. **IKEA US, TÄRNABY table lamp** https://www.ikea.com/us/en/p/taernaby-table-lamp-dimmable-beige-10508079/ - fetched excerpt (quoted fields): "Max.6.0 W"; "Shade width 4 ""; "Height 10 ""; "Base diameter 6 ""; "Cord length 5 ' 11 ""; "Shade: Glass"; "Light bulb sold separately. IKEA recommends LED bulb E12, dimmable, chandelier brown clear glass."; "Can only be used with dimmable light bulbs."; feature "Dimmable". - Supports: what a lamp listing carries (height, shade width, base diameter, cord length, max wattage, bulb base via the recommended bulb, shade material, dimmable), the dimmable-bulb rule, the LED-only wattage rating. Confidence high. - Other IKEA pages (search excerpts only): STRÅLA max 7 W, GRÖNÖ 6 W, TOKABO 4 W, TVÄRFOT 8.6 W, LAMPAN 40 W, STOCKHOLM 2025 8.6 W per bulb. Not used in the JSON. **Lamps Plus product pages** (Harp and Finial Palmer, Ronda): both returned a maintenance page. Search excerpts show the listing pattern "uses one maximum 150 watt standard-medium base A19 bulb, dimmer switch on neck, light gray cotton drum shade" and "29" high x 11" wide overall". Used only as a listing_field_hint phrasing, labelled as such. **Archtoolbox, Recommended lighting levels** https://www.archtoolbox.com/recommended-lighting-levels/ - fetched excerpt (quoted): "Library – Reading / Studying: 30-50 FC / 300-500 lux"; cites "the IESNA Lighting Handbook". - Supports: the 300 to 500 lux reading anchor (with Fotios). Confidence medium. **LEDYi, Residential recommended lighting levels** (fetched excerpt: desk lights "within 400- 500 lux"; mixed units elsewhere). Background only. ### Could not reach Wayfair table lamp size guide (429 twice), Wirecutter desk and floor lamp guides (nytimes.com blocked), Lumens.com Kelvin guide (navigation only), Lamps Plus product pages (maintenance page), TechGearLab desk lamps (directory page only), Concord Lamp and Shade luminance article (403), Grand Brass cord-length FAQ (403), Tablesroom switch types (403), Lumière Home and Homeyfad height guides (refused/403), 1000bulbs blog (no output), Tecolite enclosed-fixture page (403), LED Lighting Info and Fixfirst integrated-LED pages (403/timeout), the EU Commission light-sources FAQ (403), Mike Holt forum CRI thread (403), Reddit (no results surfaced). Amazon listings were not attempted; prior registers record that they block fetches. ## Data points used for derived metrics - `combined_height_in`: sofa-side target 58 to 64 in combined (Masdio verbatim-quoted, Tablelights verbatim); the eye-level rule (Lamps Plus, Eyely, Golden Lighting, Tablelights); desk eye line 18 in above the tabletop (Everything Depot quoting Lamps Plus). - `shade_to_base_ratio`: 2x (Fenchel; Tablelights' 6 in base → at least 12 in shade), 1.5 to 2x (Kevin Francis). Band 1.5 to 2. - `max_led_lumens`: 100 W-equivalent LED = 1,600 lm (FTC chart; ENERGY STAR) drawing 12 to 14 W, some near 20 W (SlashGear). Formula uses 15 W per 1,600 lm as a conservative middle. A 60 W socket → about 6,400 lm of LED headroom in principle (in practice limited by available bulbs); IKEA's 6 W rating → about 640 lm, roughly one 60 W-equivalent bulb (800 lm at 9 to 10 W would slightly exceed 6 W; IKEA's recommended bulbs are lower output). - `yearly_energy_cost`: 3 h/day and 11¢/kWh (FTC leaflet verbatim; 16 CFR 305.23). 60 W → $7.23 (the leaflet's own sample). 10 W → $1.20. - `efficacy_lm_per_w`: ENERGY STAR floors 50 lm/W (portable desk task) and 70 lm/W (inseparable other SSL), verbatim. ## Against the existing add-on schema `zamana-expertise/data/schema-parts/furnishings/decor/add-ons/lighting_fixture_lamp.jsonc` has `bulb_base_required` (enum e26_e27_medium, e12_e14_candelabra, g9, gu10, other) and `max_wattage_per_socket`. `lamp_shade_base.jsonc` has `fitter_type` (spider_washer, uno, clip_on, other) and the four shade dimensions plus harp height. `machines/electronics/add-ons/led_lighting.jsonc` has `light_color` enum, `color_temp_kelvin`, `lumens`, `cri`, `dimmable`, `location_rating`. The decor standard has `materials`. Proposals only; nothing edited: - `bulb_base_required`: split e26_e27 and e12_e14 by region, and add `b22_bayonet`. E26/E27 interchange but E12/E14 do not (Bright Ideas), and B22 is the UK and Australian standard; a lamp sold in those markets will say B22. - `lighting_fixture_lamp` lacks `bulb_included`, `switch_type`, `cord_length`, `dimmable` and `safety_listing`; all are on IKEA's page or in Lamps Plus listing text. `dimmable` matters on socket lamps because it forces a dimmable bulb. - `led_lighting` lacks `rated_life_hours`, `warranty_years`, `flicker_claim`, `battery_runtime_hours` and `power_source` (plug-in, USB, rechargeable); the cordless segment is invisible to the current schema. - A shared `light_distribution` (CIE five bands) could be derived for both add-ons from shade material and type. - `location_rating` (damp, wet, outdoor) and the IP code are different vocabularies; portable lamps quote IP (IP20, IP44, IP65). Consider accepting an IP code. ## Branches - lighting_job = reading or desk work → ask brightness, arm and reach, flicker, CRI, colour temperature. Chain: reading wants 300 to 500 lux on the page (Archtoolbox, Fotios); task lamps are the ones that state lumens, CRI and flicker (BenQ, Dyson, DeskForged); reach and aim are what reviewers test (DeskForged). SUPPORTED. - lighting_job = room glow → ask light distribution, height, shade material; arm and reach irrelevant. Chain: ambient light is about where the shade sends light (CIE bands; Color Cord, Pooky) and glare control by height (Lamps Plus, Eyely). SUPPORTED. - lighting_job = bedside → ask switch type, height, cord length, colour temperature; arm irrelevant. Chain: Wirecutter's bedside criteria (switch reachable, 5 ft cord, dimmable), 24 to 30 in height (Masdio, Tablelights), 2700 to 3000 K convention (Feit, Pro Lighting). SUPPORTED. - lighting_job = mood or accent → ask power source and colour temperature; CRI, flicker and arm irrelevant. Chain: cordless lamps are a few hundred lumens (Poldina 256 lm) which suits a table setting; CRI and flicker matter where people look closely (Golden Lighting). WEAK on "flicker irrelevant" (a flickering mood lamp still flickers) but acceptable because mood lamps are not looked at for long; logged. - light_source = standard bulb socket → ask bulb base, max wattage, bulb included; rated life and flicker irrelevant to the lamp (they belong to the bulb and dimmer). SUPPORTED (IKEA "bulb sold separately"; DOE and NGLIA on where life lives). - light_source = LED built in → ask brightness, colour temperature, CRI, rated life, warranty; bulb base, max wattage, bulb included irrelevant. SUPPORTED (ENERGY STAR 12.1 and 17; Moonlight Design). - dimmable = yes → ask switch type, flicker, colour temperature (for dim-to-warm). Chain: dimming is where PWM flicker appears (IEEE: PWM is 100 percent modulation; Waveform on low-frequency PWM dimmers) and dim-to-warm is a dimming behaviour (DOE). SUPPORTED. - power_source = rechargeable cordless → ask battery runtime, IP rating, brightness; cord length, bulb base, max wattage, bulb included irrelevant. SUPPORTED (Flos, Lightology, Heal's fields). - power_source = plug-in → battery runtime irrelevant. Trivial. ## Numbers in category.json and how many sources stand behind each | Number | Sources | |---|---| | 450 / 800 / 1,100 / 1,600 lm for 40 / 60 / 75 / 100 W | FTC leaflet (verbatim), ENERGY STAR brightness page | | 3 h/day, 11¢/kWh, $7.23 for 60 W | FTC leaflet (verbatim), 16 CFR 305.23 | | Kelvin scale 2,600 to 6,600 K | 16 CFR 305.23; FTC leaflet draws it | | LM-80 6,000 h minimum; TM-21 cap 6x | Wikipedia, Hyperlite, OlamLED | | Driver 73% + 1%, LED packages 7% of failures, 212 M hours | NGLIA 2014 (chart read as an image); DOE 2009 on failure modes (no figure) | | ENERGY STAR L70 ≥ 25,000 h indoor and ≥ 50,000 h inseparable; Ra ≥ 80, R9 > 0; dimming 100 to 20%, ≤ 24 dBA; warranty 3 vs 5 years; 200 lm and 50 lm/W desk, 70 lm/W other | ENERGY STAR V2.2 (verbatim); single source but the primary document | | IEEE 1789: < 0.08×f low risk, < 0.0333×f no effect, 1,250 / 3,000 Hz, PWM 100% | IEEE 1789 (verbatim); Waveform (8% and 3% at 100 to 120 Hz) | | CRI 80 / 90 / 95 with R9 about 0 / 50 / 90 | Waveform; Golden Lighting for the 80 to 89 vs 90 to 94 reading; ENERGY STAR R9 > 0 | | 300 to 500 lux for reading; < 300 lux unpleasant | Archtoolbox (IESNA), Fotios | | 2700 to 3000 K bedroom and living room; 3000 to 5000 K office | Feit, Pro Lighting | | Dim-to-warm 2700 or 3000 K down to 1800 K | DOE SSL, Bees Lighting | | Combined table plus lamp 58 to 64 in; bedside 24 to 30 in; table 24 to 34 in; floor 58 to 64 in; desk 15 to 27 in | Masdio and Tablelights; Tablelights and Everything Depot; Eyely and Govee; Everything Depot (single, flagged) | | Shade width 1.5 to 2x base; height one third (or 60 to 70 percent of body) | Fenchel, Tablelights, Kevin Francis; Lamps Plus, Fenchel, Everything Depot vs Kevin Francis | | UL 153: 15 degree incline; 120 V scope | UL 153 preview (verbatim) | | 40 million torchieres, 189 fires, 11 deaths, 300 W | CPSC (quoted) | | CIE bands 0–10 / 10–40 / 40–60 / 60–90 / 90–100 | AGi32 docs, Manufacturer.lighting | | 100 W-equivalent LED draws 12 to 14 W (some near 20) | SlashGear; FTC chart for the lumens | | E26 26 mm, E27 27 mm, E12 12 mm; B22 UK/AU/India; E12/E14 not interchangeable | Bright Ideas, Glowryte | | Poldina Pro 2.2 W, 256 lm, CRI 80, 9 h, IP65; Bellhop 3 W, up to 24 h, IP20, 3 h charge; PC Portable 3.5 W, 10 h, IP44 | Lightology; Flos; Heal's (each one listing; brand-specific facts, not generalised) | | BenQ e-Reading Ra 95, 500 / 1,000 lux, 35.4 in, 2700 to 5700 K, 18 W | BenQ page | | Dyson 850 lm, CRI 90, < 1 percent flicker | The Lightie quoting Dyson | | 5 ft minimum cord | Wirecutter via mirror; IKEA TÄRNABY 5' 11" as an example | | EU: no luminaire label since 25 Dec 2019; light sources A to G from 1 Sep 2021 | LEDVANCE FAQ (verbatim); Commission FAQ unreachable | ## Dropped - Colour consistency between a pair of lamps (SDCM / MacAdam steps). Real, sourced (ERCO, Any-lamp), but it only matters for pairs of built-in lamps and nobody lists it; the advice collapses to "buy the pair together, and the same bulb batch". Kept here. - Heat inside closed glass shades shortening LED bulb life. One verbatim line (Luxeon Star) and two search excerpts; not enough. - USB charging ports and night-light modes as facets. Common bullets, but they do not change which lamp lights the room; fold into switch and features text if the UI wants them. - A weight facet for tip resistance. UL 153's 15 degree test is the real signal and sits under `safety_listing`; stated weights are missing too often to filter on. - Lux on the page as a derived metric. It needs beam data no listing has. - The Kruithof curve as a usable grammar. Listed in visual grammars only to say not to draw it. ## Trimmed detail - `rated_life_h`: BenQ's "up to 17 years, 8 hours per day" is 25,000 hours in disguise (17 × 365 × 8 ≈ 49,600 h; so it is nearer 50,000 h L70 maths); either way it is lumen fade, not driver life. - `colour_temperature`: Fotios's range of credible evidence is about 2500 to 6500 K and interior contexts only; the conclusion is about pleasantness ratings, not sleep or circadian effects, which this register does not claim either way. - `light_distribution`: UL 153 defines a torchiere as an uplight bowl with the bulb hidden; ENERGY STAR (RP-16) as "an indirect floor lamp that sends all or nearly all of its light upward". Both land in the CIE indirect band. - `switch_type`: Hue's default after a power cut is full warm white, which is why a smart bulb on a lamp with a socket switch surprises people at 3 a.m. - `flicker`: ENERGY STAR makes makers report Pst and SVM to NEMA 77 but only optionally meet its limits; the metrics never reach retail listings. ## Corrections after the blind check (2026-10-21) A fresh agent graded eight load-bearing numbers against the cited sources (raw text via pdftotext and curl), tested the four split questions, and graded every branch leg. Grades: 5 supported, 2 partial, 1 contradicted. Changes made: - **Contradicted.** The NGLIA Figure 5 labels were swapped: the chart reads LED packages 7 percent and driver controls 1 percent, not the other way round. pdftotext scrambles the pie labels; the page was re-rendered as an image and read. The register now says 74 percent driver (73 power supply plus 1 controls) and 7 percent LEDs, in `light_source`, `rated_life_h`, the first trade-off, the first judgement and the reference line. - **Partial.** ENERGY STAR's L70 floor is 25,000 hours for indoor luminaires but 50,000 hours for inseparable luminaires, which is the built-in LED lamp this facet describes. `rated_life_h` typical and the reference line now say both. - **Partial.** Tablelights gives bedside lamps as 26 to 30 in where Masdio gives 24 to 30; the height facet's typical range now notes the narrower figure. - **Partial.** The Lightology Poldina Pro page says 9 hours in its spec and 12 in its blurb, and 6 or 6 to 7 hours to charge; `battery_runtime_h` now says so. - Waveform's CRI page gives R9 at 80 CRI as "around 0" in the body and "25" in its summary; the register now says roughly 0 to 25. - `brightness_lm` said reading wants 500 lux; aligned to the 300 to 500 lux used elsewhere, and the reading judgement now says Fotios measured room pleasantness, not reading. - `safety_listing` claimed UL 153 marks the bulb the lamp was tested with; the preview text only requires lamp replacement markings, so the sentence now says that. - The energy-cost and efficacy metrics need the lamp's watts, which no facet carried; their dependencies now name the listing field. - Branches: flicker is no longer made irrelevant by the mood answer (ICNIRP calls it the one clear acute effect) nor by the socket answer (the dimming branch asks it); the plug-in branch now also covers USB-powered lamps. - Questions: the checker found the cordless question generic (it would sit unchanged under vacuums or drills). Now "Stays plugged in, or carried to table and patio?". The light-source question says why it matters ("Standard bulb you can replace, or LED built in?") and the dimming question is "Dim for evenings, or on and off is enough?".