Will definitely post beamshots once the weather clears up.
I did some more lux readings. I did 20 meter shots instead of 25 (for 25 meters in my house I have to put the light against the extreme wall of the house, 20 is easier.) This time I put the light on a tripod and walked over to the lux meter while lit, and moved the meter around within the beam. I noticed the “peak hold” feature on the lux meter (which I had used for previous measurements) is more of a “last value” than “peak.” The results I got are a bit unexpected.
BLF GT 2930 lux (back calculated to 1,172,000)
The Sceptre 5800 lux (back calculated to 2,320,000) (is that even possible?)
Not believing the measurement, I tried it a couple of times, The meter consistently read 56xx-57xx lux.
My lux meter is pretty cheap. It’s one of the LX1330B meters. If the reading is accurate, holy moly!
P.S. is there a standard methodology for collecting lux measurements? I’ve not done much measuring before.
It always depends on the camera and the environment.
The best you can do is just make the image look like what you see IRL.
Also, make sure you’re standing to the side or behind the luxmeter when measuring, just so that you don’t have any light bouncing off of you if you’re wearing a white shirt or something.
20m should be accurate enough but you can always do 25 or 30 to be safe.
Fitting the 78mm DX lens into the head (I did this back in 2013 or so)
The lens was slightly too big in diameter to properly nest into the head. Also, the thickness of the lip is much thicker than the original lens of this host. I had to make modifications to the lens and to the bezel.
I filed the lip down until it nested into the head. Huge pain.
I had to dremel off part of the bezel.
After a hack job:
After the modifications, the gap between the bezel and the head is miniscule.
Here’s a photo of the Osram Flat Black LED installed in The Sceptre:
Looks kinda dirty, doesn’t it? I accidentally burned the white surround when the wavien collar moved with the light on full power. Smoke started coming off the LED! OOPS!!! It seems fine other than the burn mark.
Further measurements taken on this light (at 15 meters) have been in the 1.9 mcd range. I think the 2.32 value may have been a fluke. I also modded a GT with a flat black @ 4.5 amps, an Optolife lens, and a wavien collar - and it measures at 3.26 mcd at the same 15 meters. I’m still working on the GT but those are my preliminary values.
Possibly later on I can take some longer distance measurements.
I’ve made a new LED module for this light. I had bought some CULNM1.TG leds a while back but never got around to installing them. I picked up a copper mag heatsink from VOB. I cut the lip off and added a set screw to retain the module. I like this method of retention. The 16mm mcpcb & LED were soldered in place. This was not possible with the previous Flat Black build due to the thermal pad being in the electrical path. I’m using an LED4Power 6a driver.
The copper height was very close to the right height for the Wavien collar, but a little bit short. I 3d printed a spacer for focus.
The wavien collar was glued on with shoe goo. I recommend this adhesive because it holds firmly, gives time to achieve focus before hardening, and will peel away from the collar for ease of re-use down the road.
First, the Vf I am measuring of these CULNM1.TG LEDs is higher than what others have reported. My lab power supply shows 4.7v at 5 amp draw. I have ordered a 17mm single mode 5.1 amp buck driver from MTN.
Second, my 3d printed focusing spacer ring is extremely thin (.4mm) and warps from the weight of the wavien collar as the glue cures. I am working on another design.
I got the light finished up with the Mtn buck driver. The initial lux measurement was disappointing - around 1.4 mcd, or 3500 lux measured at 20 meters. The beam looks sharp and well defined. The LED is not performing as I had hoped it would.