I’m looking to outfit my friend’s boat with headlights and would like to have a combination spot and flood LED. But there are options on the LED type, and the optics. seems most mfrs are using 3W LEDs with parabolic reflectors and a flat lens. But then there are the 5W OSRAMS with the “fisheye” lens (double convex?) and also 10W LEDs and one mfr is using 15W leds shining into a single monsterous parabolic reflector.
I’ve read a little about light beams and everything says the it’s all in the optics with big and round ruling… I saw this in a test last night running a 0.5W 3015 led bulb in a big 6” handheld incandescent spot 12VDC light (the old handheld started with a 5-12W bulb and had a clamp to carry some sort of mongo 12VDC battery). the 0.5W led didn’t throw as much light as the 12W incandessant (not surprised) but it threw a ton of light which I attribute to the mongo optics…
back to the headlights… I see there are options with round lights and light bars coming with several 3W leds or less but larger LEDs (5, 10, or 15Watts). And the lights with less but larger LEDs are much more expensive for a given amount of total power. I guess the logic is that if one 3W beam will shine 50 feet, then two 3W beams will light up that spot 50 feet away now twice as brightly but not extend the original “light beam” to 100 feet…
can anyone comment on beam distance (or luminosity) comparing many 3W leds vs fewer but larger leds? what about the 3W crees with parabolic refflectors vs the 5W osrams with fisheye or the cree 10W leds. I’m looking for a combo flood around 72 watts (maybe up to 100w?) which has at least 40W of spot…
wait, 53 reads and nobody has a comment! I googled lighting forums (maybe LED light forums or DIY LED, I don’t know now…) and budgetlightforum came up top with candle power forums. you guys are the kings of light!
I’m asking about light beams. a concrete example of is it better to have twelve 5W leds (say the osams with fish eye lens) in a lightbar or have six 10W crees with parabolic reflectors? (or we could compare the 3W crees with parabolic reflectors to 5W leds or 10W leds but then the math doesn’t come out for available lights except for maybe a 60W). see below “information” from a gro light manufacturer which is touting 3W crees over 5W OSRAMS for lumens per watt:
I think it may be more productive to ask what you are trying to accomplish with the lights. Boats don’t often have “headlights” in the automotive sense. If you’re looking for docking lights a set of fixed, flood lights work well.
Navigational lighting such as finding channel markers require a movable light, the more throw the better.
And for fishing, well I don’t know cause I don’t fish.
I have a 19’ bow rider I use on a lake in NH, I find a hard driven single LED with a large reflector works great for navigating at night. I prefer a warm tint over cool, seems to provide less glare but that’s personal preference.
We motor offshore often at night riding many hours in the dark. The headlights should allow us to see waves (the ocean is very changeable and also since we sail far offshore, there’s changes in topography and then winds change too…). We need to see waves in front and to the sides so we can adjust speed and course in handling the waves as we push our light planing hull over them. It’s also critical to see objects in the water that we might hit such as buoys (fish pots and lobster pots),trees and railroad ties or containers or sea turtles… & I would also like to send a beam far out to search for buoys at night (but we did just get radar which should work). The buoys are mostly reflective which helps far off. I was thinking a pair of combo flood/spot bars 60-120watts. But as I write now thinking perhaps one bar as a combo bar to see everthing for sailing and one aimed as a pencil spot to search or see buoys. I’ll switch them independently.
You liked single led with large reflector… as compared to a light bar… but why?
I mainly use my light to spot bouys at fairly long distance on calm lake waters. Luckily there’s reflective tape or paint so not too hard when using a light with good throw. I don’t have to deal with the other hazards you mention.
This is a generalization but all things being equal a single LED in a light with a large reflector is a much better thrower than multi-emitters with smaller reflectors (or optics).
I would suggest two or three of the flood light bars mentioned above permanently mounted port, bow and starboard for the hazards. Then either a large single emitter hand held light or 12V DC hand held or mountable search light for navigation.
Gary, I feel your pain. Bay and Ocean racer and sailing instructor.
First an answer that will have appeal in this crowd.
Assuming that the above link is a bit over the top.
Lets re think this?
The radar hopefully will help tons with “seeing” the big ships (and that is huge, pun intended).
For a powerboat as boat speeds are higher and you have a ready power source, so it might make sense to install supplementary lighting, but the ocean is a big place so you may want to carefully pick your battles in your specified objectives.
For sailboats offshore. There is a reason why red lights are on sailboats, and that is the well known fact that RED does not blow out the Rods like white light does.
“Rod Details
The rods are the most numerous of the photoreceptors, some 120 million, and are the more sensitive than the cones. However, they are not sensitive to color. They are responsible for our dark-adapted, or scotopic, vision. The rods are incredibly efficient photoreceptors. More than one thousand times as sensitive as the cones, they can reportedly be triggered by individual photons under optimal conditions. *The optimum dark-adapted vision is obtained only after a considerable period of darkness, say 30 minutes or longer, because the rod adaption process is much slower than that of the cones.
*The rod sensitivity is shifted toward shorter wavelengths compared to daylight vision, accounting for the growing apparent brightness of green leaves in twilight.
While the visual acuity or visual resolution is much better with the cones, the rods are better motion sensors. Since the rods predominate in the peripheral vision, that peripheral vision is more light sensitive, enabling you to see dimmer objects in your peripheral vision. If you see a dim star in your peripheral vision, it may disappear when you look at it directly since you are then moving the image onto the cone-rich fovea region which is less light sensitive. You can detect motion better with your peripheral vision, since it is primarily rod vision.
The rods employ a sensitive photopigment called rhodopsin.
Rods Do Not See Red!
The light response of the rods peaks sharply in the blue; they respond very little to red light. This leads to some interesting phenomena:
Red rose at twilight: In bright light, the color-sensitive cones are predominant and we see a brilliant red rose with somewhat more subdued green leaves. But at twilight, the less-sensitive cones begin to shut down for the night, and most of the vision comes from the rods. The rods pick up the green from the leaves much more strongly than the red from the petals, so the green leaves become brighter than the red petals!
The ship captain has red instrument lights. Since the rods do not respond to red, the captain can gain full dark-adapted vision with the rods with which to watch for icebergs and other obstacles outside. It would be undesirable to examine anything with white light even for a moment, because the attainment of optimum night-vision may take up to a half-hour. Red lights do not spoil it.
These phenomena arise from the nature of the rod-dominated dark-adapted vision, called scotopic vision.”
Considering that navigation buoys have night flashing lights on them this helps a lot and if you want to look for the daymarks at night a hand held thrower (In red would be best) could be very useful.
But trying to mount enough white lights to the front/bow to give you visibility to see everything you list in a rocking and rolling boat (as opposed to a nice stable car that is really only looking for the lane markings) is a scope of work that maybe is not cost effective.
However having a good red (search the rigging light) and flood lights mounted under the main spreaders (I think an mtg2 or two) on each side would be greatly appreciated when working on deck at night (obviously not for navigation).
As the boat has a “light planing hull” I will assume that the standard electrical budget when offshore comes into play. Something to calculate is just how much juice is used for hours and hours of night sailing (with the proposed spot/flood lights) (hay land lubbers don’t understand that one does not just pull over at night when offshore.) might wreak havoc with the Mah budget.
Better to eliminate all white lights topside and you will be surprised how much you can see! Consider that once you get in the groove you can feel the wave patterns well enough press on with minimal unnecessary banging on waves.
I am a big fan of the cree “photo red” emitters, lots of fun can still be had building custom lights.
Yes, most often with moonlight we sail with no lights and see the waves pretty good. but we are in a motorboat and will push 15-20kts and catching a bad wave at 20kts sucks. hitting something big and solid like a container or tree or telephone pole would be worse.
I’m going to think about the red light but don’t think I’ll find any bright red stuff to light up the waves or floatsum. the biggest problem with the white lights out front is glare off the bow (we painted the bow front grey and will paint the rest this year) and glare from mist/fog. I have’t noticed loosing my night vision for very long after switching off the forward headlights.
and running, we have 12VDC at 40amps from the Honda 150 to charge batteries and run electronics and lights… we run a genny at night and I have an AC to DC converter (dell server 500W 12VDC supply) which I’m trying to integrate.
Did you see the link at the top of my post? Would that take care of your lighting challenge
Sounds like you have plenty of power.
As far as “seeing” submerged containers, don’t count on it, most of the time they are a few inches below the water level.
some times “ya just gotta takes your chances”.
A dark log in the water at night will not be much easier to see.
Daymarks, buoys, breakwaters, mooring balls/buoys, all are good targets though.
Oh and once you find a light solution adding a home made amber or red lens cover might be doable.
Light propagates without loss through clear air. The spot gets dimmer with distance because the spot spreads out bigger. So to get twice the range or throw you need four times as much light, because the spot is twice as high and also twice as wide at that distance. You can get that with a light that is four times as bright or with four lights. The LEDs tend to get bigger as they get brighter, so with one bright light you probably need a bigger reflector. Because of effects related to cooling you probably need slightly less total reflector area with several small LEDs.
There is no fixed relation between price and performance. A $10 light might outperform a $100 light.
The simplest way to get several small LEDs pointing in the same direction is to use a light with several LEDs.
Lights with reflectors and those with convex lenses have similar throw (range). The main differences are that most lights with convex lenses are variable focus or zoom, and that more of the light get out of a reflector (silvered or total internal reflection) light than out of a convex (aspheric or Fresnel) lens light. So with a reflector light, you get both flood and throw at the same time, while with a convex lens light you get one or the other, usually selectable.
My own light with the best throw has a Fresnel lens.
Thanks fritz. Great input. Makes me feel better about power selection (4x). & will look closer at the 5w osram fisheyes. They freznel the flood fish eye and claim extreme throw from the clear fisheye. I have to wonder why osram uses the fisheye instead of the reflector.
