Those looking to help with orbitals and our squad leaders calling them down would do well to know the following: what ship/how manny turrets effects the damage the orbital does. Also the different ammo types do different damage.

If it is a frigat with 3-4 turrets it will kill all but structures/vehicles. However a bigger/slower ship with 7-8 turrets like a desi/battle cruser it will do double the damage with double the turrets. Tanks and other vehicles right now can easily survive a frig's orbital. I've even seen them survive a destroyers orbital befor. So if you want a tank dead catch it on cool down or have AV/ another tank, work on it at same time. Otherwise you are wasting orbitals and they would serve better killing infantry.

Minmatar em orbital only does EM and is useless for all but destroying equipment/ not killing allies and wiping shields of enemies for easier kills, over a wide area wich can help on the ground but gives no kill mails.
Gallente orbital is the medium radius orbital and has the longest time between each individual hit of damage.
Amarr tactical strike is smallest area and most devastating with focused rapid damage. This orbital type is most likely to kill tanks if caught off CD even with them able to move so fast.

I'm all about them eight lazooors of doooom.

I just wish that when an orbital is called, any connected ships can add their guns into the mix, so you could perhaps have a 16 gun orbital, a 32 gun orbital, pain rain of epic.