I've seen a few bikes recently with a pulsing tail light display, as contrasted with the more normal bright flash-pause-bright flash look. That is, the light never goes all of the way off.
Unfortunately, the riders with these lights were faster than me and I never caught up with them to ask which light they were using! I liked the residual "marker" effect of having a bit of light left on, plus the "I'm a bike in front of you" signature (at least here in the USA) that the flashing gives.
Any ideas which lights have this feature, or setting? I imagine that these are multi-LED taillights and one of the LEDs just stays on all the time, while the others flash.
The only light I'm familiar with (I have two of them personally) that works like this is the Radbot. There's probably others, of course.
The Radbot 1000 is a great light, I think even better than it's closest competitor, the ubiquitous Planet Bike Super Flash, and I really do like the pulsing light feature. As for how effective it is, I don't know, but it does get my attention.
It's also more sturdy -- doesn't need a zip tie or tape to keep from opening up. The downside is that you need a screwdriver to change the batteries, but since you don't have to do that often I don't see it as a big deal.
Thought I did think it sort of went all the way off, at least for a bit, each cycle. Maybe I'm wrong though.
N+1=5: Anderson Custom Stainless, Gunnar Crosshairs, Trek Farley 9.8 Fatbike,LeMond Versailles, Klein Attitude MTB
The Light and Motion vis180 is a smooth pulse style of flasher which I think is what you are asking for. That said, I want a bright and aggressive flash - I think that is seriously beneficial in terms of visibility.
Dinotte (expensive) also has a mode that is a bright flash with some light in between (not full off). But it's flasher is good and bright and obnoxious - in other words, a perfect taillight that is highly visible.
You can adjust the intensity and rate of the flash on the Hotshot, but unsure that it can be set to have a low power steady combined with higher power burst. There is a Cateye model that has two rows of emitters that can be programmed independently of each other- one row on steady and the other on any number of flash patterns.
Of course, any of the more powerful lights will give the impression of glowing after looking directly into it at full power...
The Portland Design Works Danger Zone has two 0.5 watt LEDs and can operate in an alternating pulsing mode. It's what I use and prefer. Seizure-inducing mode is also included if you still want that as well.