Led spread without optics

Discussion in 'RapidLED' started by newguy420, Feb 1, 2011.

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  1. newguy420

    newguy420 Skunk Shrimp

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    I've been planning to replace my t5 actinics with LEDs for a while now. How do I decide if I want or need optics? Am I right in thinking that optics just focus light for better depth penetration? Thanks
     
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  3. Seano Hermano

    Seano Hermano Giant Squid

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    I would get the lens optics. It will focus your led lights for better depth, but depth and spread of the light can be adjusted by going with certain lenses. Most companies give the option of choosing b/w 40,60, or 80* optics. I think a few also have 35* and 55* as well as 45*. The smaller the number, the narrower the focus, meaning it will reach more depth. How deep is the tank and how many LEDs will you have?
     
  4. Jay Reef

    Jay Reef Feather Duster

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    You will get better depth penetration without the optics obviously however, there will be no spread. Think of it as a car's headlight. The bulb of the car is bright and produces light but with a projector or reflector behind it, you can focus the emitted light to where you need it which will enable you to get by without as many led's. They make different optics also depending on your application.
     
  5. kstafford003

    kstafford003 Feather Star

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    This is true. LEDs without optics are arround 180 to 160 degrees I think. Without lenses you will lose much of your usable light (PAR).
     
  6. Rapid LED

    Rapid LED 3reef Sponsor

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    Using optics definitely will increase your PAR readings, but optics aren't necessary for all tanks. As Seano and Jay mentioned the narrower the lens (ie. 40) the better the penetration will be, though keep in mind that optics can produce "spotlighting" (visible beams of light going through your water), especially at the more narrow angles. The wider the lens (ie. 80) the better the spread will be.

    Typically if your tank is over ~20" I'd recommend lenses, but if it's under that and your lights are going to be close to the water then it may not be necessary (I don't use lenses on my personal 18" tall tank at home). Keep in mind however that the LEDs without a secondary lens is going to give off light at about a 120 degree angle, so if you don't use lenses you may get some light spillage out of the tank (sometimes you'll get that even with lenses as well).
     
  7. newguy420

    newguy420 Skunk Shrimp

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    My tank is 24" deep and potentially going to 30". For actinic purposes, which lenses should I consider? I have a 120g that is euro-braced so I was going to use 12, 6 for each side. My plan was to have 4 pointing straight down and the other 2 angled slightly to the rear.
     
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  9. newguy420

    newguy420 Skunk Shrimp

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    One more thing, I currently have 2- 250w Phoenix 14k and 2 48"t5 actinics
     
  10. Rapid LED

    Rapid LED 3reef Sponsor

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    If you're only going to have 12 for the entire tank then you'll probably want to go with a wide angle (80, or as wide as you can get). Since they're just supplements you probably can go a little wider than normal.
     
  11. newguy420

    newguy420 Skunk Shrimp

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    how many should i be using for t5 actinic replacement?
     
  12. Rapid LED

    Rapid LED 3reef Sponsor

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    How many T5's are you trying to replace? (and what watt)