How much light is optimum?

[Greendiver]

Well I have been searching for a while now and am more confused than when I started. I am in need of a primary dive light and would like to build one myself. I am guaranteed to learn quite a bit in this process. The thing that I have to ask those of you who have been down this road before is this....
What kind of output would be considered optimum? Mostly quarries and such. I am in the Midwest so murky waters and limited vis is the norm. I assume with this, a fine pencil like beam will probably be best. But, how much?
Thanks for your thoughts and any suggestions!

 

[NorthWoodsDiver]

I would suggest you pick up the book from airspeed press about building lights, also there is a good bit of information on the DIY forums about this topic also. however with that said, I looked into building one and even had access to a lathe, milling maching, and various other tools and decided it would be best to buy a salvo.

though I haven't done it yet as I lost my job it came down to cost and quality, it was going to be fairly involved to build my own and though I prefer to build my own gear I didn't think I could top the quality of what is already in production.

in murky water, brighter is better for me so I would go with something in the 21W HID + range if at all possible, what I have now is 10Wish and it works but more would be better I think.

 

[Greendiver]

So you feel a little underpowered with your 10? What is the beam like?

 

[D_B]

FWIW (just info I've garnered from SB)
.. I have read many similar posts as NorthWoodsDiver's about going for a 20w HID instead of a 10w if you can .. even 35w, but I've also seen posts about how 35w may be too bright at times

 

[Packhorse]

Go LED. Then you can dim it down if its too bright.

A much more important question is what sort of beam do you want?
Wide at 15deg + or narrow at 8deg or less?

I have a LED system that uses 12watt ( or configurable to 22watt) and produces a true 8 deg beam and its comparable to a 21w HID.
For my use its optimum. If I wanted more light it would mean a bigger light head. If I want less I just change to a lower mode.
The only draw back ( And this is the only advantage HID offers IMHO) is that its fixed focus. But thats not really a concern for me.

 

[RonFrank]

I'd skip making your own light, and just buy one from Packhorse!

He mods a light with outstanding results.

As to output, I have a 10W HID (approx 500 lumens), and it is good for the majority of situations I am in. However, more is always more better!!

The thing one must factor in is that more power = more battery drain = shorter burn time. My HID burns about 6 hours on a charge. The same battery in a 21W would burn under 3 hours.

The HUGE downside to HID lights are the expense of the bulb. My 10W went, and they want $100 for the bulb... I had used it for 2 years, maybe 100 dives. So not the most appealing expense for such a short life. It likely was damaged traveling back from FL, but I did have it in carry on. HID lights are also useless topside. They overheat in minutes if not designed for topside use.

 

[Packhorse]

Thanks Ron.
I can do a mean LED upgrade on a 10w HID. Its probably about the same price as a new HID bulb but its much brighter and robust.
MR11 HID to LED conversion - CandlePowerForums

 

[D_B]

thats incredible

 

[Greendiver]

I will order the book from Airspeed press as suggested. A narrow beam is what I am looking for, it should help to reduce reflection from particles in the water. Is something comparable to 20w HID output reasonable for a 1st time builder using LED? Meaning about 12w then?

I've seen a picture of one of Packhorse's lamps in action, and that thing is piercing!

I appreciate the feedback. Without knowing my desired output, I really couldn't plan or begin anything. I have found a pretty good source of LED items at DX and am hoping that most other items can be found locally.

 

[Packhorse]

Without a lathe it may be difficult. You need one to make up the heatsink and aspheric lens assemblies.
A P7 LED based light can be made with simple tools.