Ultrafire WF-501 B works with flashing mode Cree XLamp dropin: Closups & beams.
I ordered the much discussed red LED Ultrafire WF-501B Philips Luxeon K2 flashlight on June 20 from DealExtreme. On July 9 ordered the Cree XLamp XP-C-R2 5-mode 90 lumen red LED drop-in module (thanks to BertieB for posting it was available). The Cree drop in works and now I have a rapidly flashing tail light (about 8 to 10 Hz, similar to the strobe flash rate of a Fenix L2D).
Forewarned of DX's erratic quality control, I was disappointed but not surprised when I first turned the stock WF-501B on to find it had 1 mode, "ON" and "ON". One of the ON modes was a bit erratic so I suspected a short and per a thread on Candlepower forums I knew metal chips or swarf from machining were not always cleaned out (also sometimes bad soldering). I completely unscrewed the light into its five major sub-assemblies and spotted a small sliver of metal inside the tailcap (part with the switch) that looked to bridge across the contacts. After carefully removing it with some fine needle-nose pliers, the light had both an ON and OFF mode. Impressively bright, as others have posted.
I prefer at least some of my rear lights to flash, ideally the distinctive PB Superflash's or some of the Dinotte taillight's modes. When BertieB posted about the Cree drop-in with a flashing mode, I boldly ordered it.
It arrived today and appears to be an almost identical reflector and brass threaded module end to the WF-501B's stock module with a different LED and circuit board (more on those later). Unscrewed the stock module, screwed in the Cree module, and it worked. Beam shape very similar to stock, about as bright (maybe a tad brighter).
There are some differences in the mounting of the LED to the PC board. The stock module I got has some hard white glue beneath and extending out from under the LED (see photo) Anyone know if this might be thermally conductive epoxy?
In contrast, the Cree drop-in does not have anything extending out from underneath but is very close to the PC board. (see photo). I'm uncertain if it actually touches the board but I could not slip any of some 0.003" plastic film underneath the LED. Any comments on this heat-sinking vs. the stock?
The Cree reflector also has a white plastic ring on the back where it could contact the leads from the LED (see photo).
Finally the beam shots.
Coming attraction: Outdoor beam shots at distance with comparison to the Dinotte 140R-AA-R Taillight.
Video took a while, but here it is
Took quite a while before I had a good night to shoot my amateurish video plus lots of help from the household computer expert to get the raw Quicktime video to something we could then edit out several minutes of inactivity and add the titles, but here it is. I only recorded the flashing mode of the Ultrafire+Cree and my favorite flash mode of the DiNotte.
Originally Posted by weavers
As I note in the YouTube description, due to the limitations of my video recording to duplicate the wide range of illumination your eyes detect, both lights look much dimmer in the video than you would perceive them. Both are quite bright.
I should have also taken a rear view video of both, but did not think of it at the time.
Ultrafire with Cree Drop-in vs DiNotte 140L side-by-side beamshots
Here is the Ultrafire WF-501B with the Cree drop-in on high vs DiNotte 140L-AA-R on high in side-by-side ceiling beamshots in response to a YouTube question regarding which is better.
Good question but no simple answer. The Ultrafire's deep reflector gives a fairly narrow very bright beam with nice spill outside the central beam. The DiNotte is the opposite; it has a very shallow reflector and stepped-type lens resulting in a relatively broad even beam than is not as bright in the center. In flashlight terminology, the Ultrafire is a "thrower" while the DiNotte is "floody".
Which is better? It depends. If you want to be seen from a greater distance in back of your bicycle, for example riding at night on a relatively straight, high speed road with few intersections, I think the Ultrafire is a bit better (with the flashing/strobe Cree drop-in). On the other hand, if you are in lower speed limit residential streets with lots of intersections, the DiNotte may be better because of its wider beam. On a dollar basis, once you have invested in the 18650 batteries and a good charger, you could buy several Ultrafires and get about as wide and bright a beam as you want versus a DiNotte or two.
My impression is the total lumens of the two lights are roughly equal but you would need an integrating sphere to sum up all the light from all the angles to really tell.
I provide two exposures because one picture from any camera is incapable of recording the wide range of light intensity that your eyes can perceive. Even these two, one with a fourth the exposue of the other, do not represent what they look like; both beams are entirely red but the central beam is so bright that the camera sensors are saturated and record it as "white". Our eyes are capable of perceiving about 12 stops or 2^12 in a scene while a camera records about 5 to 6 stops or only 2^5 or 6. A better technique is to do high dynamic range photography which I may try, but no time for that tonight.