Surface area vs intensity in taillights
 

I was looking around and came up this:

http://www.reallite.com/details.htm

GI-NORMUS (4" x 6") taillights for bikes. Dorky, yes, but practical, maybe? What do others think about shear surface area vs intensity in a tailight?

After all, cars don't use Dinottes (or something equivalent) in back. They use wider areas of less-intense lighting, and maybe there's a reason for that in terms of visibility. Maybe.

Just throwing it out there and wondering if anyone has experience with some giant taillight like this.

Where are they available?

I use an 18 LED 4" x 6" tail light. I also have a PB Superflash. I haven't compared the two side by side but the 4 x 6 light throws out a lot more light than the PBS and it is visible for over 1.1 miles based on a test I did. The 4 x 6 light has become my preferred light. I bought mine at Mill's Fleet Farm for $13. Had to make a bracket to attach it to my rack.

That particular light is OK. But not very bright. When it first came out it was ahead of the pack, now it is obsolete. But, still functional. A very bright small light can be more visible that a large light that is not as bright. Most of the new lights are brighter and smaller.

The Realight........

Pro - good visibility from an angle

Con- eats batteries like crazy !! Rechargeables go fast too.
you need a screwdriver to change the batteries on the road (after taking the light off the bike).
Obviously needs a lot of space. Heavy.

There are many lights much smaller, even with only 2 aaa batteries, instead of the 4 aa in the realight,
That are much, much, brighter. Many of the small lights can be seen farther away but, not as good as the realight from an angle. There is a huge number of lights that will work for you. If you have the money, get a Dinotte, if you want to spend less get a Planet Bike Superflash, or the new Cat Eye Tl-Ld 1100. This has been tested and recorded to death in these forums.

My light is 1"x12" and is also visible for over a mile. When it comes to tail lights, I definitely think that bigger is better. After all, the goal is not to illuminate the ground but to grab the most attention from all angles.