Heckflosse Posted April 14, 2012 Posted April 14, 2012 Great post - I have been round in circles for months trying to figure out what to buy. +1
Bike Lore Posted April 17, 2012 Author Posted April 17, 2012 Lol!!! These guys ears are huge.... if he goes fast he can fly I am sure.
HaydenE Posted April 17, 2012 Posted April 17, 2012 Hannes, just out of interest, where do you see the future of lights going? Currently there is probably nothing that can touch the input/output ratio of LED's - is there a "but whats next?" on the horizon, or will LED's dominate for a long while with regards to the affordability/light output ratio?
HaydenE Posted April 17, 2012 Posted April 17, 2012 Taking into account that LED's are becoming more and more affordable, not just for cycling but also domestic use
Bike Lore Posted April 17, 2012 Author Posted April 17, 2012 Hay Hayden. I don't think the next change will be so visible as the change between incandescent, florescent and LEDs was. LED stands for Light Emiting Diode and that word Diode stands for component with two electrodes called the anode and the cathode. In poppulre use it is for a semiconductor material. I think the next change will be in the application of the technology and how it is made. on other word the material used and how it is made. Check this video of where LED will take us. LED's have a long way to go. one of the major problems that is blocking LEDs is heat. Strange as it sounds. LEDs just can't handle heat very well. So fitting them in a car head light running at +10W is a huge problem for them because 3-4 Watt is going in to light the rest is heat. That is why you don't get OEM installing LEDs in car with normal Halogen mountings. Also down lights are to cramp for the 25W LED that you need. I am not saying you don't get OEM Head lights. You do but there a complete redesign which addressed the heating problem. Something else that is always overlook is the driver. An LED needs a driver that takes the input power and controls it so that the LED can work. Most drivers are about 85% efficient. that 15% wast should be take in to considerations. You get drivers that are 95% efficient but as always it is costly. If you are building a new house or car then it should be able to design for it but it is a limiting factor. Cost at the moment is only an economy of scale problem. If the heat problem is addressed then the price will drop to a few cents. What will be after LEDs is not so clear. I think like the combustion engine the Florescent light has a lot of hope but is not as lucky as the combustion engine with the lead it has in development. I don't think people notice how Compact Florescent lights has improved over the last 2 years. CFl has been over shadows by LEDs but really it is amazing and there is still lots of room to improve. But LED will win in the end I believe if the heat problems gets addressed. LED technology as we know it has a theoretical limit above 330 lumen per watt, that is 100% efficient. so we are 1/3 there. or should I say 40% of the energy in to the LED becomes light. The projections that I have seen is that at 2025 it should be about 50-70%. or 200 lumen per watt at 10 Watts power. Well heat is not a problem for cyclist, so we will for a longtime enjoy the benefits for the improvements on LEDs
Tri-coach Posted May 8, 2012 Posted May 8, 2012 Not about who you can see.... it is about who can see you!
Bike Lore Posted June 9, 2012 Author Posted June 9, 2012 MagicShine/Pyrolight comparative review This is a very informative review and a must read if you plan to buy a light. Even if the 3 lights aren't the light you are considering the information will be applicable.
TNT1 Posted June 9, 2012 Posted June 9, 2012 I have a light that says it is using a 1watt Cree chip. Is there a way I can objectively determine its' actual output? I mean I have a ledLenser H7 to use as reference, but how would I do that?
The Guy in Pink Posted June 9, 2012 Posted June 9, 2012 I have a light that says it is using a 1watt Cree chip. Is there a way I can objectively determine its' actual output? I mean I have a ledLenser H7 to use as reference, but how would I do that?That one watt chip puts out about 325 lumens, if it is post 2010 bit less pre 2010
nickelass Posted June 9, 2012 Posted June 9, 2012 I use an H7 lenser on my head, and two torchs with cree chips on my handlebars.the lenser is rechargeable,the lamp cost R600,and works well.There is an advantage because of the adjustable beam,and I have this feature with the handle bar lights as well.I found the handlebar lamps an irritation as the batterys li_iron were weak over 3months.I happenened to have a 6volt lead acid battery from other home made lights and wired these in with a regulater and onto the handlebar lamps.My resulting light is excellent and the beam radius totally adjustable while cycling,maybe this is the answer if not to improve output is give the cyclist the choice of how to put it out there depending on the trail conditions? I have no problems with the 800 gram weight of the lead acid battery,have it in a saddle bag, have not tested the run time yet but think it may supprise me.Certanly a lot cheaper an many other lamps out there and easy to get a replacement battery when needed.
TNT1 Posted June 10, 2012 Posted June 10, 2012 That one watt chip puts out about 325 lumens, if it is post 2010 bit less pre 2010 Ok, but I'm trying to find out if there is some DIY method of testing the output?
The Guy in Pink Posted June 10, 2012 Posted June 10, 2012 Ok, but I'm trying to find out if there is some DIY method of testing the output?Things are never simple as actual and percieved light ouptputs are different things.http://www.colorkinetics.com/support/whitepapers/Evaluating_Light_Output.pdf
Bike Lore Posted June 10, 2012 Author Posted June 10, 2012 Ok, but I'm trying to find out if there is some DIY method of testing the output?Well if you have an Android phone you can download a lux meter. it uses your phones camera. Then shine the light in question on to a white wall or paper about 50-150mm away. measure the reflected lux by placing the phone next to the light facing the wall. The idea is to read the reflected light. this takes out any optics effects. . then do the same for the other light. that should give you a very good idea of how much brighter one is over the other. Play around with the distance or get a real lux meter. To determine the actual lumen is not really possible. Well not in a DIY setup.
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