Loving the videos and the feedback and the enthusiasm for new lighting technology in extreme places. Thanks everyone for the complements!
This will be starting to get off topic, so I'll try to be brief and relevant.
Beam shots are very difficult to take in any way that is
truly useful to the viewer; still photos are hard enough but when you're taking between thirty and sixty of them every second things get pretty complicated. Looking at the relative brightness of some pixels on a screen can only portray the relative brightness of the actual event so well, and perfecting the accuracy is a science.
When I film in extreme conditions like a cave I use a Panasonic HDC-SD1 which utilizes
three 1/4 inch CCD chips to create a
digital rendering of the
light collected by its (quality glass) fixed primary
lens as well as any secondary lenses I attach, or I use a ContourHD helmet camera which has only a
single 1/4" CMOS sensor and has only one fixed wide-angle lens to work with. Some cameras can utilize the finest lenses, and collect telescopic quantities of light onto their very large sensors - but I think I did the best I could with the money I had when selecting my video gear.
The surface area of the sensor(s) and the amount of collecting power a lens has is only part of the equation. My helmet camera has only an automatic exposure mode, and the manual exposure settings in my prosumer camcorder are uselessly awkward to access. Sure, camera sensors are boasting lower minimum lux requirements than ever before, but they're also ignoring the ever important issues of color rendition and dynamic range despite higher resolutions - and more pixels isn't better pixels! Any digital video sensor is going to "have less exposure latitude (dynamic range) than modern [film,] they tend to 'blow out' highlights, losing detail in very bright parts of the image." These facts combine to make a digital video camcorder a poor tool for properly accurately capturing an artificial lighting environment.
Make one that's just plain scrabbling along with whatever your preferred illumination level is, that would be great. -With practical momentary turbo applications!
But when I change to turbo mode, the camera will simply close the aperture and reduce the exposure - a second of washout and then everything looks the same (with perhaps hopefully better clarity and color rendition).
Brighter
is always better as it means more information sent to the sensor
but as a film maker I have to prioritize
evenly lighting things to combat washout and underexposure. The only thing that filming the path ahead at medium mode versus turbo will show are the limitations and reaction times of my camera. Also if I framed the shots better the foreground illuminated bits wouldn't cause the camera to focus and set exposure on them and we'd see more of the throw beyond. If I could lock in the exposure and focal distance and cycle through the modes of the flashlight all you'd really see was how narrow the range of my camera is (either some blackness, detail, or whiteness - depending on where I set the exposure and what light mode I was in). As long as
something in the field of view is sufficiently lit, the camera will try to normalize its settings to match and things will all look the same. I totally agree with the idea that proper depiction of practical application would make a stellar video! ...it's just hard to pull off. Spelunkik certainly did a good job there with his little Flip!
This light is definitely bright enough for video... if you have a camera that does okay in low light conditions.
Bright enough indeed. A camera sporting a sensor that "does well" in low light conditions may also still collect light poorly, or in a poor manor, and have no way to assure any sort of good color rendering. A low dynamic range and lousy lens can still make a really fun video with lots of bright pixels in it, but the image will still be crudely assembled. With no control over exposure and focus, the camera will choose to adapt to the brightest spot which is usually the closest bit so the spotlight is lost in the background just because the sensor can't capture that range in the face of the proximity flood - alternatively the hotspot washes out and causes the exposure to drop below what is necessary to define detail from the dimmer portions of the beam.
Ironically, the lousier a camcorder's dynamic range, the better a flashlight will look (or perhaps seem more powerful) through it due to the washout it produces! The best cameras can adapt the image they capture to be suprisingly similar in apparent brightness at quite different lighting levels thus capturing the widest band of light levels within the shot, whereas a cheapo camcorder will be unable to capture either the darkest or the brightest subjects at once and make it look like there are more drastic jumps between modes than a better camera would render.
So in conclusion: Alas! If I wanted to make a video of a flashlight underground that had as much information in its images as in the beam shots taken by our most skilled users here on CPF, I would be looking at taking $4k worth of DSLR camera and lenses and support gear perhaps into some of the harshest environments there are. I think what I needed here was really a bullet list script and a better battery - my next underground flashlight review will be better still I'm sure, and I'll leave the truly informative images to the folks who have mastered taking proper beam-shots. As for the headlamp I should have touched on how to access the advanced modes and program the high setting, the cool way that giving the tailcap a half turn securely locks it off, and gotten a larger variety of shorter but more diverse action-shots of it in use. Better audio next time too for sure.