CFLs vs. LEDs

[parktrot]

I am in the design stage of my first ROV and am trying to decide which route to go down on the lighting path...

I am a professional photographer and as such I am obsessing over the video component. To that end I realize that providing adequate light is going to be a major factor. I want a lot of light and not just ultra bright pinpoints I want even diffuse light. To do that I figure I am going to need a large quantity of wide angle reflectors with high intensity lights. At this point I am thinking of using a combination of high intensity LEDs (10w +) mounted on heatsinks and ultra high power 12V compact florescent lights. Any thoughts? I am looking for an potential flaws you see in my system?

Thanks

[MagicHat]

Hello!

Have you done anything with this project yet? It would be good for us to get some information on the ROV, i.e. what the hull is made of, where you are going to place the lights (are they going to be in the same hull as the camera or seperate "hulls"?) and how deep you are going in the water.

I am working with electronics, and I'm a big fan of LED's. As you probably know you can get a lot of different LED's, both when it comes to light color and light intensity.

The problem with LED's is that they generate a lot of heat, but as you go a couple of meters down in the water the water temperature will constantly be 4 degrees celsius down to the bottom (that's just how it is). If you have a steel hull and attach the LED's directly to it this would provide very good cooling!

Another thing is that LED's need resistors to be wired in series with itself so that the current through the diode doesn't exceed its maximum (which would cause it to burn off). The current through the circuit can be calculated if you know the total resistance and the voltage over it, using this formula:

[quote=Ohms Law]Current (Ampere) = Voltage (Volts) / Resistance (Ohms)
[/quote]
The current must not be larger than the LED can handle. You can see this in the datasheet of the diode. I can help you with the resistor calculation if you need to.

I don't now much about fluorescent lamps. Are they any good (camera wise)?

[maximillion]

I might stay away from florescent, they will require a ballast and the light produced vs. an LED wouldn't be as good? All you can do is experiment though.

[thamlin]

Im using led's on my project, because they actually produce less heat due to the wattage usage than a standard florescent. Only reason i know that is because i just retrofited a whole aquarium. Normally your not suppose to incase a LED at all due to the manufacturers recommendations, because of the heat that they do produce, but we did test on these LEDs from osram and found that they can take being inside a enclosed fixture.

Now one other thing. It doesnt matter if your hull is pvc or aluminum. Due to the natural thermal cline when the unit drops down to the bottom of your pond, your pool or lake, it will cool the lights anyways, how much? well metal conducts cold better than plastics, but you would definately decrease the temp of them either way. good luck