Review: OSRAM "GLOWdim Filament" LED Light – Nice Try

Actually offers the new OSRAM/Ledvance – LED-“Pear” called “GLOWdim filament E27 7W” also in the measuring laboratory about what the manufacturer promises: “Fadenlampen” technique for retro fans, combined with continuously variable color temperature spread between around 2700 and 1700 Kelvin, a color rendering index of significantly over RA 80 and slightly more than 750 lumens light output. The first impression of the light color – shows supported by an amazing colour measurement why this “classic A 55” model from the first batch is still no adequate replacement of light bulbs.
Actually, Osram/Ledvance had a good idea: led “Filament” lamps attract a wide layer of buyer, preferably of the same light as by incandescent lamps have want – only stromsparender. If however you connect such “Pears”, “Drop” or “Candles” on a dimmer, will be disappointed. Either they are not dimmable, or the “chip on record”-LED strings – change down rules their light colour during the old glow fruit at the dimming not only darker, but also becoming redder, “fleecy” lights.
This behavior is now using the “GLOWdim filament ‘ technology will be imitated. Inaround 11 euros expensive test lamp two glass pad on both sides with LEDs are controlled to separate, and a thread-type lights up with 1700 Kelvin (a kind of “Amber”- or “amber” color), the other with some over-3000 K.
At full power, all four – according to laboratory measurement shine after two hours continuous operation – with about 766 lumen luminous flux and a very good efficiency of 114 lm/Watt. At lowest Dimmstufe only the two funzeln filament of 1700 K (in the photo on the left bottom left and right) with a total of around 50 lumens to himself.
In between the two types of relative intensity can be mixed infinitely and in the perceived combination offer pretty much every colour temperature of 1700 to 2700 K(example top right). As far as the theory. Why this works but not so great in practice, has several reasons:

  • LED Fadenlampen light have with only four against the vertical of inclined filament already a habituation need dispersion. In a 90-degree angle to the LEDs, color fringescan make(Detail photo of a drop shadow)and black stripes within the light beam. Partly so at two mixed LED light colours creates the impression of at least four different colour temperatures. When only two wire light, the light beam is still inhomogeneous and low half value angle.
  • If the color of the used LEDs too far from the ideal curve municipalities away, quickly creates the subjective impression an unpleasant Farbstiches. Do this enough already the strong variation of one of the two LED Fadentypen. Also in the mix of two proper types of LED colour temperature arise some strange light colors
  • The “Filament”-LED lamp production in Chinais still handmade in part. Since it can happen that the thread design not perpendicular into the housing is mounted, but flips easily from the central axis. That when lamp switched off negative stands out when she has a clear cover (photo).
  • To exploit the full range of possible temperatures and brightnesses, only with suitable dimmer. If you have an incompatible, standard household dimmer without Justierschräubchen or through the connected LED lamps, with a minimum burden is not obtained, could be below ‘ be an end around, for example, at approximately 2200 k to 200 lumens. This annoying buzzing noise and/or high-frequency flicker occur frequently.

The OSRAM “GLOWdim Classic” offers what by all

At the just 7 watts of strong “LED GLOWdim classic A 55 E27” (pdf datasheet) you get all these disadvantages in concentrated form. The first thing that struck all observers were confronted by me with two copies of the same production batch: A clear yellow / greenish tint, if all threads with lit full power – the light color was sallow and uncomfortable. The second was the inhomogeneous beam pattern vertical shadow lines, low light upward, but more to the side. Here you get all these effects in a photo served – of course not a 1:1-Abbbild of reality, but an acceptable approximation:
Somewhat friendly the other temperature extreme with the 1700-K-“Filament”-Duett – obviously very stressed red-orange presented itself, so absolutely incandescent-like:
Would you like to see the corresponding color fidelity standard motives to do this?Please – here are the photos with the two model bikes against a white background, with white balance “Daylight” and (almost) without editing (I’ve got the right picture due to excessive darkness at only < brightened 100 Lumens and a better Comparability):
At least the appearance left can not convince me, also not when compared with other”Warm white” LED lamps with 80 just about RA. The background for example, colour somehow reminiscent of mustard or the like. The rich red of Ducati, as well as the deep blue of the Yamaha look like with a yellow green veil covered.

Almost all values lie in the “green zone”

Most readings from the Pro Lab of my cooperation partner “David communication” are actually quite okay. They range from approximately 766 lumen luminous flux at 6.7 watts in power consumption and a electric power factor of 0.89, 2650 Kelvin color temperature (with the tip in the spectral diagram at 614 nm), “General color rendering index’ RA 83.5 (with 22.5 for the most difficult Additional reading R9 =”Red saturated”,Pdf-download of the measurement protocol) up to 50 lm at < 0.5 Watt, 1698 K (tip approximately 629 nm) and also RA 83.5 (R9 = 23.5, Pdf Protocol).
There are light absorber first by the beam diagrams of Goniophotometers, which each showed an underlying eight in an upright position of lamp – with strong “dents” up and down. The half value angle decreased slightly by around 288 (full power with all four LED threads, chart) on 267 degrees (lowest Dimmstufe, two “filament”, chart).

The colour location provides the best explanation

The clearest indication of the cause as “yellow green” or “Wan” perceived colour of the appropriate colour delivered the “GLOWdim classic A 55” at about 2700 Kelvin: he was far above the ideal ofPlanck’s black body curve – even beyond the 6-step MacAdam ellipse (SDCM,graphic right). Actually need to LED bulbs in the EU lie within this ellipse. Who but now razor-sharp deduces that this OSRAM lamp might not be marketable, has made the Bill without the Ledvance technology strategists.
Who appointed namely that that the Center the < 6-SDCM-ellipse according to the International Commission on illumination (CIE), not necessarily directly on the curve must lie, but also on the “Judd line” of the respective “Correlated color temperature” (CCT) should be.
These lines range up and down a bit and should include those color locations, which are perceived as the same color of light (graphic left, Wikimedia Commons, license: Public Domain).

Everything is actually for Ledvance

According to the Ledvance research and Development Department of the desired colour for the lamp model tested was x 0.463/y 0,420 – exactly on the “Judd line” for 2700 Kelvin, but far above the black body curve. The chromaticity coordinates measured by us x 0.4759/y 0.4324 lie still within a < 6-SDCM-ellipse to the former. Accordingly, the light meets the EU requirements and is thus quite marketable.
Also, the first reactions by distributors and large customers on the new model have been positive; also the Ledvance-interviewed me, “Strategic Category” step wanted to have perceived even no unpleasant color cast. We will however try further towards the black body curve to push the color coordinate in the next batch.

No real help for consumers

Such academic discussions about technical values can be of course could care less about the normal customers. Alone the perceived quality of light and the brightness achievable with existing dimmer and light colours are what counts for him. That’s where the problems go further. Not only the performance data, a two-year guarantee and the EU eco-label A + are printed on the back of the packaging, but also a Web address (, under which information about the dimming give it to (photo montage below).
When you click on the address, you will see that nothing so you see – no help for seeking advice, no dimmer compatibility list. Instead, so what can you find on This Ledvance page. You however don’t really advance the various links in the right column, because the here tested (stand 13.9.2016) is missing “Classic A 55” model there.

Phase angle works part just fine

So that went in my attempts: on the adjustable young phase control dimmers, the rules worked best – flicker-free, continuously and over the entire path of the dimmer – 7.2 Watts (total power consumption dimmer + lamp) to 1.1 W, where only the two 1700 K threads weakly glowed. The span so ranged from under 10 to full 100% of the maximum power – exemplary!
The cons: Lamp and dimmer buzzed intellible especially at medium settings – audible in quiet environment around one meter distance. Also, the “Flicker tester” app “Viso systems” at 100 Hertz reference frequency reported Flicker values by index 0.0 and 5% rate (dark) index 0.1 and 45% (center position). For comparison, a normal desk there index 0.1 and 23% and a slight flicker in the display of my Nikon camera. The Professional measuring device “FM ch” at “David Communication” proved maximum flicker rate to 31% at 100 Hertz. Could be that also flicker-sensitive people consciously or unconsciously perceive it.

Smaller amount of control on the phase dimmers

On the not adjustable “loading” phase dimmers from the hardware store everything remained quiet; while the flicker values climbed however considerably higher: According to the knob position between index 0.1 at 25% and 0.2% 67 – since it will be very critical. Also suffered from the length of the rule that was enough just from 3.4 to 6.9 Watts, included only the lower half of the dimmer way, and with the theoretical lowest temperature 1700 K (See carton and label detail in the picture on the right) far could not be reached.
Surprisingly nothing essential has changed because if a 40-watt incandescent bulb was connected in parallel as additional load, though this is mostly a probater way to a broader rule of time a dimmer might be too high minimum load. Even the cross-check with an adjustable Sygonix phase dimmers brought no improvement – there I was able to turn on the Justierschräubchen, as I wanted to.
In practice this means that you with your available budget – flush mounting dimmer may not the complete potential of “GLOWdim” – retrofit can exploit – which would be very bad just when this LED lamp type.

Moderate temperatures, low power consumption

After all, you do not worry about the heat. In my hanging, open test version there was down to the hood maximum 48 degrees after two hours full power on a normal switch up on the socket and not more than 30 ° – there get in touch guaranteed no blisters. My “energy master”-amateur meter indicated by the way 6.6 Watts at this time – so also slightly less than the 7 W nominal power (see lamp imprint in the picture on the left).
The nominal life of the 46 grams of light “bulb” made of glass and aluminium composite material is Ledvance with 15,000 hours of light or 100,000 switching cycles. Thanks to maximum diameter 6 cm, it meets the A60 lamp standard, is about 2 cm longer than 60-W/E27 glow fruit but with 11.4 cm. According to tradition in the OSRAM LED the model designation is based but anyway not the size, it’s the Equivalent of light bulbs. This would be an imaginary copy of 55 Watts at 750 lumens – therefore the test candidate “Classic A 55” and not “A-60” means. The Stromsparpotenzial calculated from our laboratory is thus almost 88 per cent.

My test result:

“Normal” and relatively easily dimmable led “Filament”-retrofits there are already not very often – LED Fadenlampen, also its colour temperature can change with the brightness, are still rare, because it takes a lot of knowledge and advanced technology for (right, the view from above by the glass cover on the LED strings and the extensive electronics into the lamp-socket).
OSRAM/Ledvance now has the “LED GLOWdim filament” for just under $11 in this delicate segment of niche targeted and clearly landed the implementation optimum of a really nice idea. Even if Ledvance played it on demand: many bulbs fans from the target group will probably not especially like the yellow-greenish color of light at full brightness and the limited dimming; noise and flicker-sensitive people could also get problems depending on the available dimmer model.

EU requirement is made to the paper tiger

Not change the predominantly good laboratory measured data the subjective “pale” appearance. As long as Ledvance interprets the EU specifications for the chromaticity coordinates as incredibly generous (and apparently still legal!), we can use the < 6-SDCM-rule for color consistency an interior light bulb actually act as mindless paragraphs in the bin. I can remember on a such strong deviation from the ideal color temperature curve anyway, my Recent lamps tests at any – and there were already some bad candidates in our laboratory.
The generosity of my five, strict LED rating scale should end therefore already at maximum one and a half stars. I give this but still a half for the good idea and the courage of Ledvance, as the first major company in the lighting industry and practical to implement it (“Philips Lighting” comes next), and land at
two stars.