How to avoid grand finale burnout?

[One for the Mouse]

I be at WDW in August so I thought I would spend this Forth of July figuring out our Nikon to get the perfect firework shot.

Here are my specs for my first night out shooting:
Camera: Nikon D90
Lens: Tokina SD 11-16mm
Exposure: 0.2 sec (1/5)
Aperture: f/4.5
Focal Length: 13 mm
ISO Speed: 800
remote shutter trigger
Tripod

I thought I was getting great shots on the normal fireworks:

My problem came when the grand finale came and there was too much light.

Now this was at one of the Midwest largest firework displays so maybe Disney's grand finales won't be as concentrated. Would you change the exposure right before the finale?

Thanks for your help! Two days before the next fireworks to shoot.

More shots can be found here: http://www.flickr.com/photos/lauraandnick/sets/72157620666348809/

 

[jcb]

I just read this article from Nikon on shooting fireworks: http://www.nikonusa.com/Learn-And-Explore/Photography-Techniques/fvttrrsx/1/The-Fireworks-Show.html

He uses a lower ISO, smaller aperture and longer exposure.

 

[photo_chick]

Disney fireworks are bigger and brighter than those. During the finale last year the sky was pretty much covered in fireworks.

Low ISO, small apertures and long exposures (several seconds to a minute) are often used for fireworks. And a lot of people also use a neutral density filter to get really long exposures. Look at WDWFigment's work, he's got some really great fireworks images.

 

[jcb]

These two are at the same speed/aperture (.5 and 7.1 at 400 iso).

On the first, the exposure was too short, while on the second (the finale) well, it speaks for itself.

 

[handicap18]

For the Grand Finale, I would keep my ISO and shutter speed the same (I like 200 and 4-10 seconds). Normally I use f/10, but for the Grand Finale you need to close that aperture a lot. I would drop it down to f/22 or smaller during those last 10-20 seconds. There is A LOT of light. You need the slow shutter speed to capture everything, but to wide of an aperture will allow to much light.

You also may want to do only 2-4 second bursts at f/22.