Compare
Dive Xtras
X-Ray Mk1
Against:
- General
- Lux / Lumens Explained
- The Process
The Great Light Test
We at Dive Xtras set out to put the X-Ray Mk I up against the best Dive Lights in the business and see where we stood.
The X-Ray is designed to be a technical canister light worn on the back of the hand and primarily used for communication between divers. This criteria requires an spot of intense light with low spill levels to allow effective communication in bad visibility without raising ambient light levels and preventing others from communicating with each other.
There has always been controversy over the best way to achieve this, but based on our experience diving, we have found that the most effective way is to have as much light as possible in a spot that is not too large, but not too small either.
We decided a two foot diameter at ten foot distance was optimal. This will be controversial to many who believe that peak intensity is everything, sacrificing all else for the smallest bright spot. This is a simplistic argument and ignores the fact that many factors contribute into making a beam work well underwater.
Lumens
Capturing all the light from a bulb will give the current lumen outputLux
Capturing the amount of light hitting a certain areaVideo Light
Spot Light
Lumens
Lumens is the measurement of the total amount of light. If you collect all the light from a bulb you would have its current lumen output.
Lux
Lux is the measurement of how much light is hitting a certain area. ie the brightness or intensity. Lux is affected by distance. The farther you from a light source the more the light is able to spread out making it so less light hits the target area. Imagine light as a particle looking like this =
Focus
Lights with the same output can have very different lux levels depending on their focus.
Distance
Lights with the same output can have very different target lux levels depending on the target's distance from the bulb.
The Process
Our results are based off a repeatable scientific testing procedure. We have described it here for you to understand and can provide more details for those looking to duplicate it.
To start with all the lights were fully charged using the manufactures supplied charger. In a blacked out room (lux levels less than 0.5 lux) the lights were totally submerged in a glass tank containing circulating water maintained at a constant temp (64-66 deg F) to simulate an actual dive where the lights have the benefit of water cooling. The beam was focused to the tightest spot and centered on a surface 10 ft away.
The lights were turned on and at 5, 25, and 45 minutes (to allow for warm up and simulate an actual dive) lux measurements (the lux meter used was a Anaheim Scientific H100) were taken every 2 inches across the surface. At each test a beam shot was taken ( aperture 4.0, shutter 1/6, ISO 100, 24mm Lens) This resulted in 3 sets of data each with 47 measurements and a photo.
This data was then averaged to give you the results you have seen. Peak Lux figures are simply the peak Lux from the data, Lumens are calculated from the Lux readings and the area of a 2 in wide annulus centered on the respective reading.
