It's more likely to be the camera distorting than the mic.

Many cameras have the level control *after* the mic. preamp - so the mic. pre. can be distorting and you can't turn down the level as the control is later in the chain.

Insert a pad (-10dB for example) in-line in the mic. cable (you can get these as XLR barrels from such places as Canford Audio) - this should cure the problem.

If this cures it, it was a camera problem - if it still distorts it's the mic.

I use Rode NTG-1 (which is actually the same, as NTG-2, but without a battery) with Sony PD-170 camera. I agree with Steve, that a weak battery can reduce the max SPL (it is in the mic's specs...)

So, the first thing I'd recommend is to use NTG-2 without battery, with phantom power from the camera. Secondly, during a wedding reception, when DJ plays music at huge levels, I switch mic attenuator on my PD-170 to -20db, and that helps to eliminate distortions. If your camera doesn't have internal attenuator, you need to use an external one: -10db to -30db, depending on the situation. There are many available, even with a barrel switch.

At least, my experience...

Here's the link I referred to earlier: http://www.dvinfo.net/forum/all-thin...ud-venues.html

I believe the NTG2 overloading is a known issue, it has been raised here several times and I have seen it in a colleagues' system. If the mike overloads no amount of post-mike attenuation will correct it, the diaphragm is just maxed out. Take a listen to the samples...
/ Battle Vaughan