rolling,
A diffuser film just above the dice might well present a more uniform in density image but but one that much larger and difficult to collimate. It would aid in getting rid of a donut hole but it would also result in even more of a flood. Nothing wrong with that unless one was seeking a tight collimated beam.
Mel_PL,
In your illustration, over 75% of the light (radially speaking relative to each die's "Z" axis) will encounter a reflective surface optimized for its neighbor die which is even further off axis than a community surface based on the the common "Z" axis. I don't know what the resulting beam would look like but would anticipate less overall collimation than before.
Guys,
One of the first hosts I selected for experimenting with the P7 was a PR-T head I had. I figured with the anodized integral bulkhead of the PR-T and a surface larger in diameter than the P7, it would be an easy mount and good thermal start. The McR-27 reflector has the longest focal length of all of the McR series and this is the best suited in regards to collimation of the large image of the P7. The McR-27 is such a shallow reflector that the lion's share of light gets out the front without ever making contact with the reflector and the PR-T head can be used without any reflector for a reasonable Mule flood.
From evaluation on the bench of the P7 I identified what I needed to do to a McR-27 reflector to bring the focal point of the reflector in alignment with the image of the P7. The resulting beam was a monster wide flood field with a collimated hot spot in center and also a visible donut hole. Of course in actual use, one can get past the artifact of the donut hole but it is there.
If you want to take this light output and bend it to your will, the deper the reflector, the more light you bend. Because of this, I took a McR-45 and modified it for focal alignment and also had to remove material from a "step" to allow it to drop down into the PR-T head. As expected, the beam had a much more intense spot but still a donut hole artifact.
I then tried a stock McR-27 and McR-38 which put the focal point of the reflector well in front of the image. This is what I used to do with the LuxV's to remove the donut hole at the expense of collimation. You have to look very hard with these to find some irregularities in the spot.
I consider the P7 as a flood source plain and simple and found that the McR-45 with image backed out from focus gave a nice thrust of light where the spill beam has been choked down by virtue of the reflector's depth and spill is impressively bright as it also has some divergent and wayward streams of photons from the off axis source coupled with the orange peel of the reflective surface. I would call the beam a concentrated flood with a large and hot center. It does have some throw to be sure but nothing compared to a single, on axis die in similar reflector.
The geometry of the McR-27 and McR-45 which is the same reflector just grown deeper allowed me to visit a convertible idea and the HD45 head was such that I could modify it to replace the PR-T bezel cap.
As with the PK2 mod, I used a SOB 1625 in this PR-T mod and the head is hosted on a Balrog 3x123 pak.
I realize this is already a long winded post but I am going to extend it with some more observations and rambling which should just about complete my P7 musings.
In dinking around with the P7, I realized a great candidate for hosting and modding with the P7 would be the good old Pelican M6. If one had an original with the threads in the tube for the LE, you could have a great foundation for hosting the P7. Further, the M6 can be bored to host the 16 mm Li-Ion cells and you can add I think they are called A-19 extenders to grow the length of the tube? Anyway, as an alternate to the Mag hosts yet still of mass and surface in line with thermal considerations for the P7, I think the Pelican M6 would be a good foundation.
I think most important in my observations with the P7 was the realization that here you have a single LED capable of major lumens which is great but dang if you need this much light often!! The P7 is a LED that could be better managed with a driver of variable output; especially given that it is basically a flood source. If this LED is driven across its full range, I could see a 4 level driver as well justified. Without variable output, I think the P7 would be quite limited in its use unless it was in a
very large reflector with a sole purpose of distant illumination.
The more I think about the P7 the more I think I can appreciate what I believe team PK has in store for this LED. It will be interesting to see the level of sharpness in projection they choose for the P7.
Personally, if I can get a hold of a buck driver that has variable output (30mA-2800mA range) and capable of being driven from the Makita 18V Li-Ion, I would like to make a mule team light.
