Dive Lights, many changes, comparison chart

[CajunJosh]

You might also find this website useful:

Beam Comparisons for LED Dive Lights - Dive Gear Express

 

[Madacub]

. Is there any site that breaks down CURRENT dive lights on the market and does reviews/comparisons?

Hahah. Nice joke!!! But seriously, the first question is: Do you think they are providing the right data for us to make judgements?

CHALLENGE: Each manufacturer should do a night underwater test of all of their products and photograph the beams at 5m, 10m and 25m, to the same target.

I don't think it is very realistic to expect them to do underwater tests. I agree that's where we are going to use them, just not realistic to expect them to go to the time & expense. And even if some did, what would that really tell us without standardizing the turbidity of the water? I suggest testing in air, in darkness. Against a standardized (white?) background. One comment on your suggested distances: You're (gasp) American! What's with the metres/meters? What happened to feet?!!! Photographs are good, but really we need to be able to show numbers, else how else to advertise without a double page spread. Please see below.

how bright it is at about 113 lumens. I just found out that a few months after I bought it this year, the SL4 is the same price and the brightness was increased to 400 lumens with the new version. That is over 3 times as bright as the original.The only issue there is that I feel like I got jipped (is that a word?) because the upgrade was so fast to come out right after they just came out with the first eLED.

As I understand it, an increase in lumens does not equal a proportionate increase in perceived brightness. Similar to sound and decibels, it is a more logarithmic scale. I'm not sure, but I've read in two places that you need to about double the lumens to perceive a noticable increase in brightness. So 113 to 400 lumens would be very noticable for sure, but if I already had a 113 lumens flashlight I may think twice before upgrading to 400 lumens if that was the only consideration. Especially if money was tight. I may wait till I can afford an 800 plus lumens unit. (And since you asked, it's "gypped". )

Boy! I'm having fun with this post!

But seriously:

I agree that flashlight specs are not very useful nor complete in most cases. I'm not an expert but I've tried to inform myself. I'd like to see other people's comments on these points:

Point 3 is not meant to be an opinion. It is meant to be a statement of fact. So maybe on point 3 specifically, comments from those who are particulary knowledgeable would be more useful

1. Lumens is not appropriate for flashlights, diving or other. Lumens may be appropriate for most house lighting, where the light is broadcast 360 degrees. A flashlight is a packaged system (bulb, lens, reflector etc) that directs a light beam in a certain direction. That is what we should try and measure.

2. Providing a lumens rating is okay, but not sufficient. But there should be enough integrity to measure the lumens "out the front" (OTF) rather than the "source" raw bulb itself. And people should be made aware that an increase of lumens from 200 to 400 does not double the perceived brightness.

3. Lumens is actually more difficult and expensive to provide a meaningful measure of than lux. Lux is the measure of illumination. Lumens is the amount of light produced by a light source, that is to say, coming out of the light source. 1 lux = 1 lumen per square meter. Lux tells us how much illumination there is on the surface we are shining the light on.

4. What we need to know is what Jax has identified, except that we need it in numbers. It seems to me that lux is the proper measure. Using lumens, especially "source" lumens, to measure the useful light of a flashlight is similar to using watts. It might work in some situations, but it's just the wrong measure, so comparisons are very often innately useless.

5. So, if I were to market a flashlight, I might say: And here are the specs (luminosity related):

a. 1000 lumens (must be OTF)

b. Beam angle = 12 degrees in water. 10 degrees in air.

c. Lux. Measured on a white wall, in darkness. Dead center, 1 meter from center, 2 meters from center, 3 meters from center. (For a wide beam angle, say 60 degrees, one could say 1, 3 and 10 meters)

i) At 5 meters: 400, 300, 100, 50
ii) At 10 meters: 350, 250, 50, 25
iii) At 25 meters: 100, 70, 30, 10

Link to actual beam shots could/should be provided.

6. Of course, luminosity is not the only thing. For color temperature, the kelvin reading should be provided.

7. Battery life is intertwined with the luminosity specs. There was an extensive thread on this - I think on candlepowerforums. Maybe we can agree that the life should be stated as that which still puts out 50% of spec. Perhaps the relevant spec for this purpose should be lumens? Just for simplicity. Of course, battery type should be specified, as well as charging time etc (this is pretty well laid out these days)

8. Whether the battery will die suddenly or will gracefully bow out over a period of X hours

9. Weight with batteries. Buoyancy with batteries.

10. Length, width, circumference of body. Material of body. Proper attachment point for inserting a split ring at the back of the body (especially for smaller lights) (And no funky designs please!) Depth rating.
　
This covers what I can think of. Dive lights are expensive and difficult to figure out. But not that difficult, as long as we accept that we need to educate ourselves and that one spec is never going to be enough. Most of this is cobbling together stuff from different sources, mostly candlepowerforums and scubaboard, as well as other sites. I make no claim to originality. I would like to see what others think.