Primary Light beam spread - what should I look for?

[kanonfodr]

Looking at new primary lights, I see some specs about beam spread but I also read how some spread patterns are not very good for communication purposes.

1.) How much will the spread of a beam affect communication, in minute differences (ie 6 degrees vs 12)??

2.) Is there an optimum spread I should be looking for?

3.) What am I missing?

Appreciate any input on this.

Peace,
Greg

 

[Gombessa]

Looking at new primary lights, I see some specs about beam spread but I also read how some spread patterns are not very good for communication purposes.

1.) How much will the spread of a beam affect communication, in minute differences (ie 6 degrees vs 12)??

2.) Is there an optimum spread I should be looking for?

3.) What am I missing?

Appreciate any input on this.

Peace,
Greg

Hey Greg,

In general, for the best communications, you really want a pencil-thin beam. I don't recall if a standard adjustable-beam HID is 6 degrees or less, but when it comes to beam spread, even a couple of degrees makes a BIG difference, so go as narrow as you can. I've almost never set my HID to any spread other than spot.

Also, I've used 18w and 21w HIDs in Hawaii, and have found their usefulness for communications very limited at recreational depths (you guys just have so much darned light penetration and visibility that the light beams simply wash out). In general, for doing more than peeking under dark ledges, I've found that the better the viz is, the more powerful of a light you need.

 

[mbsub]

Looking at new primary lights, I see some specs about beam spread but I also read how some spread patterns are not very good for communication purposes.

1.) How much will the spread of a beam affect communication, in minute differences (ie 6 degrees vs 12)??

2.) Is there an optimum spread I should be looking for?

3.) What am I missing?

Appreciate any input on this.

Peace,
Greg

Greg,

in few days you can read here in Scubaboard a big test of our VB-CAVE with the new VB-50 LED head.
I think that this review will answer all of your questions.

Michael

 

[gcbryan]

Greg, are you planning on using this light to communicate using light signals in the daytime in OW in Hawaii or is it for night dives and/or penetration dives of some sort?

 

[DiverLaura]

We should have some nice video of 5 - 8 different lights out in +/- 40' vis in lake washington over the next couple of weeks.

What you'll see is that 'in water' it is a lot different than just shining it at wall from a foot or two away.

Pencil is awesome for signaling and cutting through ****ty vis, but if you are trying to 'light up' a wall at night in good vis, sometimes a slightly wider beam is nice. Spill is what i find annoying, where you have a nice reflector and beam, but then the shroud is too short so you get light coming out sideways that can be distracting for your buddy.

the 'tweek' videos on my youtube channel show some different beams pretty well and examples of spill etc...

YouTube - ljjames33's Channel

 

[lucca brassi]

Hi ScooterGirl
May I ask what is HID lamp on Goodman handle covered with silver tape (Diverite 24W?) Nice beam ... an nice video too!
Regards !

 

[kanonfodr]

Greg,

in few days you can read here in Scubaboard a big test of our VB-CAVE with the new VB-50 LED head.
I think that this review will answer all of your questions.

Michael

Looking forward to the review.

Greg, are you planning on using this light to communicate using light signals in the daytime in OW in Hawaii or is it for night dives and/or penetration dives of some sort?

Well, believe it or not we have the occasional viz problem (I've ran into 15-ft here before, and was grateful for everyone who brought lights along), but I was also opened up to the usefulness of a big-bore primary for daytime communication, active and passive, during my recent Fundies class. My little DiveRite LED700 is ok at night, but during the day it gets washed right out for passive communication. To add to that: I'm really starting to notice deficiencies in the light that are starting to bother me.

I also visit places like Lake Travis, Monterey, and hopefully more in the future, where more powerful lighting would be incredibly useful. I dived with Kathydee while in Monterey and her 21watt Salvo was really great for keeping track of her location where my light's lower power was...evident. I hope I'm not sounding like I have Light Envy.

We should have some nice video of 5 - 8 different lights out in +/- 40' vis in lake washington over the next couple of weeks.

What you'll see is that 'in water' it is a lot different than just shining it at wall from a foot or two away.

Pencil is awesome for signaling and cutting through ****ty vis, but if you are trying to 'light up' a wall at night in good vis, sometimes a slightly wider beam is nice. Spill is what i find annoying, where you have a nice reflector and beam, but then the shroud is too short so you get light coming out sideways that can be distracting for your buddy.

the 'tweek' videos on my youtube channel show some different beams pretty well and examples of spill etc...

YouTube - ljjames33's Channel

ScooterGirl: Some of those were DAY dives?!?! WOW!!! That is some dark water y'all have over there. The videos were interesting and super useful for seeing differences in lighting. If possible, could you identify whose light is what so I have an idea of what to look for in a light?

All: I'm going diving tonight and I will try to take some pictures and video so you can see what I'm talking about, as far as my light's limitations.

Peace,
Greg

 

[TSandM]

There is beam spread and then there is focus . . . I have a 6 degree light head on my Nite Rider, but it's poorly focused and isn't very bright.

The Salvo 12W LED I got to dive had a very focused, intense center beam and then a large, softer spill -- it drove me crazy at first, because I kept thinking the spill was the light from another diver nearby. But you kind of get the best of both worlds that way.

Most of the well-known light brands have a pretty intense center beam (Light Monkey, Halcyon, Green Force, Sartek). I have not found a 21W HID very useful for communication in the daytime in Hawaii, though, unless I can shine it directly into my buddy's mask.

 

[DiverLaura]

here is a comparison video of several of the Halcyon lights that i shot over the past few weeks... Vis is a bit less than ideal at times, but it gives a good idea of 'beam'. You can see the New EOS 12w LED, the New 21w HID, an older 18w HID, and a 10w HID...

YouTube - Halcyon Light Comparison

 

[HenrikBP]

Thanks for the comparison. Makes it easier to understand what people mean when light beams are discussed.

Henrik