what is the physics behind having a longer vane as appose to a shorter vane and visa versa?

is it only speed? cause it would seem like a longer vane would keep arrow flight more consistant?

Some is personal preference, some have a function.

Shorter vans are easier to get thru shoot thru rests without contact. They are lighter for the speed freaks. They don't catch as much cross wind.And I think Blazers look cool!

Longer vanes steer the arrow better. They are easier to see as the arrow flies. They control larger broadheads better.

Just depends on what you want to get out of them which ones you use.

The shorter ones are a little taller than the longer ones and they weigh about half as much. Because they are taller they can have a similar effect concerning "catching the wind" and steering the arrow that the heavier long vanes have. Feathers ( I have not used them yet but am getting some tomorrow) are long and present a larger surface to "catch the wind" and steer the arrow but are light so you kind of get the best of bothe worlds. But then, in inclement weather, feathers (from what I am learning) can get wet and misshapen.

The type of vane or feather you use is determined by what you need to accomplish with your arrow. I am using blazers on my present arrow because 4" vanes would make the spine to stiff (extra weight to the rear of the arrow). If my arrow had a weaker spine and I needed to make it stiffer then I would use the heavier, longer vanes. I choose my fletching based on the arrow and how I am building it, not on how it will look when finished.

Bohniong's website gives a good explanation between the longer and shorter vanes. While Blazers are shorter as bruce says they are a little taller. Anotehr factor is that they are stiffer than a nrmal plastic vane. Therfore, you can get the same control with a blazer that you get with a longer vane.

Long vanes where developed as a trade off to feathers. However, being heavier and not as stiff they're not perfect. Feathers are better but are easily damaged. Manufactures also make plastic vanes that are cut like feathers. Still not the same. They are stiffer than regular long plastiv but still heavier and brittle.

Not until the Blazer, or other short vane, have manufacturers been able to get feather like control, and weight, out of a plastic package.

If you still want to use Blazers you can use wraps to increase weight without resorting back to long vanes.