Romisen RC-F4 Beam Problem! (w/pic)

I received my RC-F4 recently and turn it on and noticed that there is like a moon-shaped hole in the beam just outside the hotspot. It's not as noticeable in the picture but when I see it on the wall with my naked eye, I can clearly seen that there is an area kind of shaped like a 'C' just outside the hotspot is darker.



Now, I know in practical use outside I won't notice it at all. But it's just sometimes doesn't feel good when you KNOW there is SOMETHING wrong. All my other Romisen lights don't have any issues like this.

Otherwise, the RC-F4 is one of the brightest sub-$20 flashlight I own.

Probably a chip in the reflector, or some such. Short of replacing the reflector there's really nothing you can do about it.

04orgZx6r said:

I have the same "problem" with mine. To fix it unscrew the head about 1 and a half turns, but that just makes the hole in the middle appear at around a foot and a half rather that at just under a foot. It's just a compromise i guess. Kai sells a reflector for it, which I ordered, that some have reported to work great.
Here's the link to the reflector thread, it just came back in stock two days ago so you should be fine ordering it, anyway the link.

https://www.candlepowerforums.com/threads/193953

Click to expand...

Thanks for the link. I've order one and I will try to install it. But I am not sure how to dismantle the head to get at the reflector....

the LED is not perfectly centered in the reflector or is not perfectly perpendicular to the axis of the reflector. Its real close but not perfect and the slightly dark crescent shape is the "shadow" indicating that.

If the front end comes apart and can be put back together, it would be best to see if you can shift or tilt the LED in reference to the reflector. Once you have the reflector off you may be able to see if the LED is ever so slightly tilted off axis. Trial and error will show you that the beam has shadows on the same side that the LED is too close to the reflector on. so if you move the LED to the left side of the reflector, there should be a darker and darker crescent shape on the left side and a brighter oval beam pattern on the right side.