Vermonter73,
I can't say which is better, but I
can say that the solux MR-16 modules are
fantastic. Very, very high quality of light. And, no, mdocod, they're not running the filament at 4,000K or anything. There is a dichroic coating on the reflector to let the IR and lower end red light back through the reflector, gradually increasing reflectivity as the wavelength shortens, in a way to change the natural output curve of the tungsten filament into something more like the curve of natural daylight. So, yes, as mdocod points out, there is some loss of efficiency,
BUT,
the light down there is pretty low lumens factor light anyway. This might need some explaining:
There are two systems of photometric units when it comes to light: physical, and sensory. The physical is typically measured in mili-watts. So you might have an LED rated in mW of light output per W of power input, for example, and this would hold good for an IR LED or a UV LED. However, obviously, the human eye is not equally sensitive to all frequencies of light radiation. And in fact, below a certain frequency, we do not see any light at all, but only feel heat radiation on our skin, and above a certain frequency we also do not see any light at all, but only get sun-burnt or irradiated. LOL!
It turns out that yellow-green light at a wavelength of about 555 nm is where the eye is most sensitive. At this frequency, by definition (probably to make some integral come out nicely), one watt of physical light output equals 673 lumens of sensory output. At about 610 nm (on the red side of things, in other words) that drops to half. So even for the same physical light power, for the same measurable light output, the eye is only half as sensitive, and thus the light output in human terms is half as much.
So, the point is that even though a large amount of light energy is indeed not reflected, not forward radiated out the front of the reflector,
the percentage of lumens output lost isn't nearly as much as you might expect.
For example, I am using a 50 W solux halogen MR16 in my Polaris right now, and it is noticeably brighter, gives more output, than a Tiger11, which is about a 520 torch-lumens light. It should be, going by watts and 33 L/W and 65 percent loss figures, about a 1100 torch-lumens light. But, my guestimation is that it is about a 750-800 lumen light (about the same as a WA1185 on 9 cells). So this is a loss of about 25 percent of lumens output. The biggest problem for a highpowered portable solux light would be heat. All that IR and near-IR which is normally forward radiated now gets absorbed by whatever is behind the reflector, which is usually the head of the flashlight. This makes a 50 watt solux light, like the Polaris, heat up almost as fast (but not really) as something like a 100 watt USL using a normal reflector and a 100 watt Osram tunstgen halogen lamp.
Anyway, the upside is that the light from that lamp is the best light I have seen. It's like the pleasing whiteness of an LED beam, but with the color rendering ability and other pleasing features of an incan beam. Pretty amazing stuff, really.
In fact, it's so good that
Digital Photography Now uses one of these dichroic solux lamps to illuminate their color chart when testing digital cameras!
Colour chart
Currently we use a Gretag Macbeth ColorChecker DC chart to evaluate digital camera colour quality. The target is lit using a custom-built daylight colour temperature lighting system. Special Solux tungsten halogen dichroic reflector lamps are used, over-driven by a custom-made DC power supply to generate an even 'hotter' colour temperature (which means a 'colder' white balance) than their 4700 Kelvin rating at 12V.
Special patented Solux dichroic lamps are designed to lose unwanted UV and infra red out the back of the lamp through the semi-reflective reflector. Combined with our over-drive power supply, the actual illumination on the test target is particularly close to natural sunlight, with a well-matched colour spectrum, especially compared to so-called fluorescent daylight lamps that exhibit spikes across the colour spectrum.
Our lighting rig means cameras can operate normally in auto white balance for the purposes of evaluating colour rendition under consistent and relatively authentic sunny day light illumination emulation, something that would be impossible with the fickle nature of the British weather!
However, as mdocod says, the greater efficiency of an HID might outweigh the improved color-rendering of a solux. I couldn't say, never having comared the two side by side. I'm guessing that I personally would still go for the solux, as I find HID light a bit harsh and glaring. But then again, I'm one of those wierdo hotwire guys. Go figure.
Anyway, good luck!
