Browse Forums Lighting + Lighting Design 1 Jun 21, 2012 1:48 pm Before you buy an LED lamp, consider the following for warm white GU10 LED lamps: 1) Philips 7W outputs 290 lumens = 41 lumens/W 2) Osram 10.5W outputs 450 lumens = 43 lumens/W 3) Megaman 7W outputs 270 lumens = 39 lumens/W 4) unbranded 7W outputs 450 lumens = 64 lumens/W 5) unbranded 7W outputs 420 lumens = 60 lumens/W 6) unbranded 7W outputs 560 lumens = 80 lumens/W Now the average halogen outputs 800 lumens, so you will need about 2 to 3 times the light output, which is not currently available. More importantly, how can the unbranded LED bulb give almost twice the output for the same power input? While considering the answer, keep two things in mind. Firstly, there is no band name to protect. Secondly, how would you check the lumen output? Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Something to consider before buying an LED bulb 2Jun 22, 2012 9:23 am To be fair very few halogens are actually 800lm we found a difference of up to 35% between brands. As a lot of companies are now using Sharp/Citizen chips I can see no reason why anyone would buy any of those branded gu10's anymore. I believe light levels are less of a problem than the supporting electronics for unbranded products. Re: Something to consider before buying an LED bulb 3Jun 24, 2012 9:24 am Even taking the worse case of 800 lumens - 35%, we get 520 lumens. That means the worst halogen has (slightly) more light output than the best (branded) 10W LED. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Something to consider before buying an LED bulb 4Jun 25, 2012 11:40 am All of the new gen retrofits with the aforementioned citizen/sharp chip should all be 500+ fairly easily ie. DR700 @700lm+. Both the Philips and Osram have been out quite a while so are going to be a little behind. We recently tested a 7w mr16 @ 470lm. Getting dimmable compatibility is a real pain though. Re: Something to consider before buying an LED bulb 5Jun 25, 2012 12:25 pm Very good point! We've tried to take the lumen output and also the CRI (Colour Rendition Index - where the sun is 100 and halogen is the closest of most types of lamps at around 90) into account when we planned for our LED lights. Ultimately the decision was to go with Brightgreen's D900 (and D1000 for task lighting) - it does output 903 lumens and has a CRI of 90+. While it's not a GU10 or MR16 format LED retrofit bulb, it is suitable for new home installation choices. Refer: http://brightgreen.com/products/d900-cu ... s-1662-0-0 Re: Something to consider before buying an LED bulb 6Jun 25, 2012 8:47 pm think_wise All of the new gen retrofits with the aforementioned citizen/sharp chip should all be 500+ fairly easily ie. DR700 @700lm+. Both the Philips and Osram have been out quite a while so are going to be a little behind. We recently tested a 7w mr16 @ 470lm. Getting dimmable compatibility is a real pain though. The Osram GU10 10.5W 2700K LED lamp with a light output of 450 lumens is described in their online catalogue as NEW. For the 7w mr16 @470 lumens output it cannot be directly compared to the 7w GU10 which outputs 290 lumens since the MR16 figure does not include the transformer losses and the GU10 does include the transformer losses. If the transformer is 70% efficient then the MR16 7W --> 10W @ 470 lumens which is the same as about the same as the Osram 10.5W which outputs 450 lumens. Another thing to be careful of is colour temperature. The same Osram lamp with a colour temperature of 3000K gives out 500 lumens and at 6500K gives out 620 lumens. How easy is it to measure lumen output? Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Something to consider before buying an LED bulb 7Jun 26, 2012 10:04 am Casa, you raise some good points which people often overlook on MR16/GU10. Its not very easy to measure lumens, also how the lumens are measured within an integrating sphere can vary eg. most China figures are an LED light (often without lens) pulsed for under a second which doesn't allow the chip to heat up. Which is why your point of unbranded products rings so true. The closest thing you can do from home is find out the model of chip being used and deduct 15-20% from their specs. This is not always easy as 'Brands' can also be misleading. In fact the most annoying thing we ever did was get our light NATA tested as the lumen figure is so much lower than the competition even though I am yet to test something brighter than ours. FYI we measured 8w with an ACTEC transformer on the 7w Mr16 also the same consumption as the equiv GU10 model. Re: Something to consider before buying an LED bulb 8Jun 26, 2012 8:36 pm Thank you think_wise. It's interesting the tricks that are used to get unreal lumen output figures. I' glad you got your light tested by NATA. I would rather have an LED lamp with 500 lumens output as certified by NATA than 800 lumens from an unknown lab. The problem you're experiencing is the same one Philips and Osram have. They use real figures while the unbranded LED lamps used "fabricated" figures. Demolition August 2009, Construction Started September 2009, Completed December 2010 Re: Something to consider before buying an LED bulb 9Jun 29, 2012 4:58 pm unfortunately the market has accepted stated lumens (to an extent) not proven lumens. Re: Something to consider before buying an LED bulb 11Jul 17, 2012 1:43 pm Casa2 Let's start a campaign to educate people. This website I have looked at a few times could help educate. http://reviewleds.com/ People giving their genuine reviews is going to kill anyone who claims their lumen count to be higher than it is. There needs to be a campaign to educate people I believe firstly on the difference between lumens and watts. People still believe watts relates directly to brightness. Re: Something to consider before buying an LED bulb 12Jul 20, 2012 9:53 am Great site Gumb..... It would be nice if it was run by an independent and not BG Re: Something to consider before buying an LED bulb 13Jul 24, 2012 10:29 pm the regular bulb makers printed this on the boxes: 100W = 1340 lumen 75W = 935 lumen 60W = 710 lumen 40W = 415 lumen 25W = 220 lumen i'd recommend to buy atleast 1500lumens because 100w looks way too dim if it has to light up the whole room. or maybe use 4 strategically placed integrated lamps with 750lm each? Re: Something to consider before buying an LED bulb 14Oct 10, 2012 1:05 pm I would recommend everyone view this excellent thread comparing LED's with measured lumens. There certainly are some LED's which approach 50w halogen output: http://forums.whirlpool.net.au/forum-re ... ?t=1951172 Build Thread: viewtopic.php?f=31&t=57639 Re: Something to consider before buying an LED bulb 15Oct 15, 2012 1:26 pm Do not compare lumens - compare lux. It's silly to compare lumens when you're not factoring in beam pattern. No point comparing two 800lm globes when one is spread over the whole room and the other is focused in to a beam. Building a Delta 21 at Craigieburn - http://homeofzero.blogspot.com.au/ Deposit: 26/02. Contract: 22/05. Settlement: 29/05. Site start: 18/10. Re: Something to consider before buying an LED bulb 17Oct 16, 2012 7:53 am Lumens is a measure of absolute output. Lux is a mesaure of output over area. There's no point comparing raw output if it's all concentrated in to one point, or not evenly distributed. Building a Delta 21 at Craigieburn - http://homeofzero.blogspot.com.au/ Deposit: 26/02. Contract: 22/05. Settlement: 29/05. Site start: 18/10. 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