Osram Superstar Plus E27: dimmable, but not with every dimmer switch

What the documents show: data according to the manufacturer and the register

LEDVANCE (brand OSRAM) lists the bulb under order number 4058075602458 as LED Superstar Plus Classic A 60 Filament DIM 5.9W 927 Clear E27. The manufacturer's product database gives 806 lumens at 5.9 watts, a luminous efficacy of 136 lumens per watt, 2700 kelvin (colour code 927), a colour rendering index of Ra 90 and a beam angle of 300 degrees. In addition there are a rated lifetime of 15,000 hours according to L70 and B50 at 25 degrees, 100,000 switching cycles, energy efficiency class D, a length of 105 millimetres, a diameter of 60 millimetres and a weight of 31 grams.

For operation the manufacturer gives 220 to 240 volts at 50 and 60 hertz, a rated current of 38 milliamperes, an inrush current of 2.2 amperes, a power factor above 0.40 and a run-up time of under half a second to 60 per cent of luminous flux. According to the data sheet the bulb draws 0 watts when switched off, is rated IP20 (so for dry indoor rooms only) and may be operated at ambient temperatures between minus 20 and plus 40 degrees. LEDVANCE gives the photobiological safety as risk group RG1 according to EN 62778. On flicker, the database gives Pst LM less than or equal to 1.0 and SVM less than or equal to 0.4.

The following table separates what comes from where. The Source column means the LEDVANCE product database unless the EU product register EPREL is also named.

One detail is worth a look: in the shops the bulb is often listed at 5.8 watts, while the current manufacturer figure is 5.9 watts. The next section explains why, because the answer lies in the EU product register.

Three register entries, one luminous flux: why it says 5.8 watts in one place and 5.9 in another

The product database lists three EPREL registration numbers for this order number: 642776, 1361243 and 2505754. We looked up all three in the EU product register. The supplier is LEDVANCE GmbH in each case, the luminous flux is 806 lumens throughout, the cap is E27, the class is D, the colour consistency is 6 steps, and all three are entered as mains-operated (MLS) and non-directional (NDLS) and marked as dimmable. Three things differ: the model identifier, the market launch date and the power.

That is the answer to the watt question: over the years the bulb has been registered in at least three versions. The oldest two give 5.8 watts, the entry from April 2026 gives 5.9 watts. Which version is in your box is stated on the packaging or the bulb itself, and cannot be said for certain without looking. In practice the difference of 0.1 watt changes nothing about the light. It does change what you enter as the power in a calculation, and it shows that listings for the same bulb do not necessarily describe the same version.

The lumen maintenance factor is striking. The oldest entry gives 0.80, the two newer ones 0.93. This is the factor stored in the register for the decline in luminous flux. If you calculate with the two values, about 750 lumens remain of the 806 lumens in the newer case (806 times 0.93 equals 749.6) and about 645 lumens in the older case (806 times 0.80 equals 644.8). The register does not say which point in time the factor is based on. We therefore do not interpret it as a statement about the 15,000 hours, but only note that the manufacturer enters a better value for the newer version.

The efficiency calculation with the factor disclosed

Under Annex II of Regulation (EU) 2019/2015, the efficacy of a light source is the useful luminous flux divided by the on-mode power consumption, multiplied by a factor from Table 2. There are four factors. For non-directional light sources on mains the factor is 1.000, for non-directional without direct mains connection 0.926, for directional on mains 1.176 and for directional without direct mains connection 1.089. The register lists our bulb as NDLS and MLS, so the factor is 1.000. Nothing is extrapolated.

806 lumens divided by 5.9 watts equals 136.6 lumens per watt. With the 5.8 watts of the older register entries it would be 139.0. The class limits of the regulation are: D from 135, C from 160, E from 110. At 136.6 the bulb is therefore just above the limit for D and well below C. The manufacturer figure of 136 lumens per watt agrees with our calculation apart from rounding, and Class D is stated correctly. No criticism of the manufacturer can be derived from the figures.

For context: for Class C at 5.9 watts, at least 944 lumens would be needed (160 times 5.9 equals 944), that is around 17 per cent more light. The gap to the next class up is therefore considerable. If you want the same brightness with less power, you need to look at a different bulb type. This is our assessment; no manufacturer document answers the question.

What 806 lumens mean in daily life is explained in our lumens to watts chart. As a familiar incandescent bulb step, this luminous flux corresponds roughly to a 60 watt bulb. That is the usual industry assignment and not a manufacturer commitment.

Dimmable is only half the answer

The manufacturer calls the bulb dimmable but does not name a single specific dimmer switch on the product page. Instead there is a note to check compatibility at ledvance.com/compatibility. The LEDVANCE compatibility page gives this reason: operating LED bulbs on an upstream dimmer is not standardised technically. Dimmable is therefore a property of the bulb and not a commitment for the dimmer switch in your wall.

What can be calculated from the manufacturer figures: with a 5.9 watt bulb, about 17 bulbs fit onto 100 watts of dimmer load (100 divided by 5.9 equals 16.9). That is the theoretical upper limit. The lower limit is more important. Dimmers for incandescent bulbs are often designed for loads from around 10 to 40 watts, and the dimmer itself states the exact value. A single 5.9 watt bulb can fall below that; three bulbs come to 17.7 watts. These minimum load values are general dimmer figures and do not come from the bulb manufacturer. Look them up on the dimmer or in its manual.

LEDVANCE gives the inrush current as 2.2 amperes. It is meant as a short switch-on pulse. With several bulbs on one circuit it adds up; for this the database gives an upper limit of 118 bulbs on a B10 circuit breaker and 152 on a B16. For living rooms with a handful of bulbs this does not matter, but for long light runs or stairwells it is more likely to.

What is not documented is how smoothly the bulb runs at very low dimming levels and how far down in brightness it can be regulated. LEDVANCE does give the flicker values Pst LM and SVM, but does not assign them to any dimming level. Both values apply at full load. How flicker arises and what you can check against it is explained in our guide LED flickering: causes and remedies.

Ra 90 and 2700 kelvin in an open fitting

The combination of Ra 90 and 2700 kelvin is the real reason for this bulb. The colour rendering index Ra describes how accurately a light source renders colour samples compared with a reference. At 90 it is, according to the manufacturer, above the usual living room bulbs with Ra 80. Whether you notice the difference depends on the room. Wood, skin tones and fabrics are most likely to benefit. We have not measured anything and speak here solely of the manufacturer's figure. Our guide explains colour temperature: understanding colour temperature and kelvin.

The colour consistency of 6 SDCM is a wide tolerance. SDCM stands for the steps of a MacAdam ellipse, and 6 steps means that two bulbs from the same series can look different in warmth. For single bulbs this is unproblematic. If several bulbs hang side by side in a pendant light, buy them from the same pack, because a deviation is more noticeable there. Describing this step count as wide is a technical interpretation; the figure itself comes from the register.

The clear shape with visible filaments is worthwhile only where you can see into it. In a closed opal glass fitting the advantage is lost. In an open pendant light over the dining table (for heights see: pendant light over the dining table) or in a wall light without a shade, by contrast, the bulb remains visible. According to the manufacturer, the beam angle of 300 degrees means that light is emitted almost all round.

Rated lifetime, switching cycles and everyday calculations

The rated lifetime of 15,000 hours according to L70 and B50 at 25 degrees means that after this time half of the bulbs still deliver at least 70 per cent of the initial luminous flux. It is a statistical value, not a commitment for the individual bulb. We therefore give no guarantee period, because the manufacturer documents we checked contain none.

Calculation at three hours of use per day: 3 times 365 equals 1095 hours a year. 15,000 divided by 1095 equals around 13.7 years. At six hours a day the figure halves to about 6.8 years. The 100,000 switching cycles correspond, at ten switching operations a day, to 100,000 divided by 3650 equals 27 years. According to the manufacturer, they indicate that the bulb will not fail early at the cycle limit even in hallways and stairwells with frequent switching. In the bathroom, because of IP20: only outside splash areas.

Power consumption: 5.9 watts times 1095 hours equals 6.46 kilowatt hours a year. At the assumed value of around 35 cents per kilowatt hour used in our guide putting LED power consumption in context, that comes to about 2.26 euros a year. The electricity price is a labelled assumed value and not a current price. The manufacturer's database additionally gives 6.00 kilowatt hours per 1000 hours, which is the rounded version of the 5.9 watts. With twelve bulbs in the house, the same calculation gives a consumption of around 77 kilowatt hours, so about 27 euros.

According to the manufacturer, the operating temperature ranges from minus 20 to plus 40 degrees ambient, and the maximum case temperature at the measuring point is 65 degrees. This is relevant for very tight fittings where heat builds up. At 31 grams and a diameter of 60 millimetres, the bulb fits ordinary E27 fittings. If you want to weigh up the cap size against E14, you will find it in the guide E27 or E14.

What no source answers

There are plenty of documented figures, but some questions that matter when buying remain open. We have not guessed at them but list them here.

• Specific dimmers. The product page names not a single approved dimmer switch. Whether your model is on the compatibility list, you need to check there.
• Behaviour at very low levels. Neither the dimming range nor flicker at low brightness is assigned to a level.
• Which register version you get. Three entries with 5.8 and 5.9 watts are in circulation, and the retail listing usually does not name the version.
• Reference point of the lumen maintenance factor. The register gives 0.80 and 0.93, but not when the value applies.
• Our own measurements. We have not measured anything and did not have the bulb in hand. All figures come from the manufacturer database and EPREL.

There are also two oddities in the database: the total harmonic distortion (THD) is given there as 110.15 per cent, with no explanation, a striking value that is likely to be an entry error for a bulb of this power class. We leave it out of the table. In addition, the colour rendering index appears in one place as greater than 90 and in another as equal to 90. We work with the manufacturer figure Ra 90.

Who the bulb suits and who it does not

Suits you if you want warm white light with high colour rendering in an open fitting and want the clear filament look to stay visible. Anyone who switches often also benefits from the 100,000 switching cycles. If you dim, you should invest the half minute in the compatibility check rather than puzzling over flicker later.

Suits you less if you do not dim at all. Then you pay for a feature you do not use, and you will find simpler bulbs with the same brightness. In closed opal glass fittings you also gain nothing from the filament shape. If you need more brightness, look at higher luminous fluxes, because 806 lumens corresponds to the 60 watt step, not the 100 watt step. Similar dimmer questions are covered by our data check on the dimmable GU10 bulb.

Alternatives compared: the Philips LED Classic E27 WarmGlow is the obvious alternative to this bulb, and you will find more in the data check on the Philips filament bulb. If you want to control brightness by app or switch rather than via the wall dimmer, compare it with the Philips Hue White E27 and plan the system with our overview of smart lighting. How much light your room needs overall is worked out by the lighting calculator.

Electrical note: changing a bulb in a plug-in lamp holder is possible without a qualified electrician, but installing or replacing a wall dimmer is not. With a fixed 230 volt installation, that is a job for a qualified electrician. Switch off the circuit breaker first.

Sources and transparency

This page is built from documents, not from our own laboratory. Below are all the sources that were opened for it, and next to them, explicitly, every statement that is our own calculation or interpretation.

Sources checked

• LEDVANCE product database for order number 4058075602458 (GTIN): 806 lm, 5.9 W, 136 lm/W, 2700 K (927), Ra 90, 6 SDCM, 300 degrees, L70/B50 15,000 h at 25 degrees, 100,000 switching cycles, Class D, 105 x 60 mm, 31 g, 220 to 240 V, inrush current 2.2 A, IP20, Pst LM up to 1.0, SVM up to 0.4, RG1 according to EN 62778, three EPREL numbers, reference to dimmer compatibility. Direct access with curl returned 403; the page was readable via page retrieval.
• LEDVANCE compatibility page (in German): reasoning that operating LED bulbs on upstream dimmers is not standardised technically, and reference to compatibility lists.
• EU product register EPREL, entry 2505754 (model identifier AC92562): LEDVANCE GmbH, 806 lm, 5.9 W, E27, Class D, MLS, NDLS, dimmable, market launch 16 April 2026. Entries 642776 (AC33980, 5.8 W, factor 0.80) and 1361243 (AC45155, 5.8 W, factor 0.93) were retrieved via the register interface.
• Delegated Regulation (EU) 2019/2015: class limits and factors for total mains efficacy in Annex II.

Our own calculation, interpretation or matching

• manufacturerDocCount is set to 2: the LEDVANCE product database for the order number and the associated compatibility page. The EPREL entries are register data from the manufacturer and do not count here as separate documents.
• The calculations 806 divided by 5.9 equals 136.6 lumens per watt and 806 divided by 5.8 equals 139.0 are our own. The factor 1.000 follows from the register fields MLS and NDLS and Table 2 in Annex II of Regulation (EU) 2019/2015.
• The limit of 944 lumens for Class C (160 times 5.9) is our rearrangement of the class formula and appears in no document.
• Equating 806 lumens with a 60 watt incandescent bulb is the usual industry assignment and not a manufacturer commitment.
• The annual calculations (1095 hours, 13.7 years, 27 years, 6.46 kilowatt hours, 2.26 euros) are our own calculations with assumed usage times. The electricity price of 35 cents per kilowatt hour is an assumed value from the guide and not a current price.
• The minimum load values of dimmers (10 to 40 watts) and the classification of 6 SDCM as a wide tolerance are general technical interpretation and not a statement from the manufacturer documents.
• That the 5.8 watt figure in the shops comes from the older register entries is our conclusion from comparing the register entries. We found no explanation from the manufacturer on this.

What remains open

• Which dimmer in your wall runs cleanly with the bulb is not stated in any product document. The product page refers only to the compatibility lists, and we have not checked individual dimmer models.
• How smoothly the bulb runs at very low dimming levels and how far down in brightness it regulates is not stated by any source. Flicker values are not assigned to a level.
• Which of the three register versions (5.8 or 5.9 watts) is in a particular retail listing is not apparent from any listing text we know of.
• The reference point behind the lumen maintenance factor of 0.80 or 0.93 in the register is not given. No document explains why the factor rose from 0.80 to 0.93.
• The product database gives a total distortion of 110.15 per cent and lists Ra once as greater than 90 and once as 90. Whether these are entry errors has not been established, and we do not use the two figures.
• The Amazon ASIN of the listing discussed was not on file in our records (asin field empty). The page is built solely from the manufacturer database and EPREL, not from a listing text.
• The brief held in the archive for an Osram Superstar pack concerns a different model (Classic A 14 watts, 1521 lm) and was not used.

Checked and not reachable

• Direct access to the LEDVANCE product page with curl returns HTTP 403 (web application firewall with a JavaScript challenge). The short address ledvance.com/shortlink/4058075602458 redirects to the same page. The content was readable via page retrieval.
• The EPREL search for the model identifier 4058075602458 returns no results, because the register identifiers are AC33980, AC45155 and AC92562. The three entries were found via the registration numbers from the manufacturer database.
• The EUR-Lex address of the regulation responded to the request with HTTP 202 instead of 200.