I think the GT is better for collar AND aspheric lens, because the head consists of two parts. You can screw the reflector-housing off from the LED-Base. With this you can set a better focus to the aspheric lens / fresnel lens.
But the GT is better for XHP70.2 because you can use it with more batteries and the cooling-fins are much better.
I think you (and me) need a second GT! (because I have similar ideas).
Keep in mind, for the XHP70.2 with an other driver (e.g. 12V and 8-9 Amps), that the MF04 has 2S2P Battery and the GT (2x)1P4S.
I have the Jaxman Z1, just curious that the focal length (around 27mm) is greater than the collars (12.5mm), will this affect the size of projected die or will there be light spill?
The focal length of a lens has nothing to do with the focal length of the collar.
The NA of the lens is what matters since the collar has a 60 degree opening only.
Ok, but wouldn’t the Z1 lens still be something like 27mm from the led to focus the die and in turn have a gap between lens and collar top where light from collar would widen as it exits the aperture of collar?
The 2013 Wavien patent describes a parabolic collar, which they claim works better than a spherical one, particularly with mutiple LED emitters.
“The parabolic reflecting collar is made by rotating the parabolic curve around the axis which goes through the focus and is parallel to the directrix. The resulting reflector is round with a parabolic surface. Light emitted from the LED placed at the focus is reflected from one side of the parabolic surface, becomes a parallel beam, incidence onto the opposite parabolic surface, and refocused back to the LED itself. One major difference between this parabolic recycling collar and the spherical recycling collar as shown in FIG. 1 is that the light emitted from a point at and near the focus will be reflected by the parabolic reflector twice and back to the same point where the light is emitted. With this property, with used with packages with multiple LEDs and multiple colors, each LED will be able to perform recycling of its own light independently and each LED with its own color will be able to improve the brightness independent of the other LEDs and colors.”
Yes but that uses two parabolic reflectors, one facing forward and one facing down. You can’t replace a collar with a single parabolic reflector that is upside down.
The regular spherical collar reflects an inverted image which is why you can’t use it with multiple different coloured LEDs.
The spherical collar is better however because it only reflects light once instead of 3 times and it also reflects back at exactly the same distance from where it was emitted, which means that the reflected die image has the same sharpness as the original die, with no divergence.
That looks really good, seems like they did go away from the slice method.