Wow! The other was the first time that I had to shoot in open tropical skies with the sun in full intensity at noon and I found it difficult with just one ND filter position ... closed the iris to f8.0 but still ... the sky was burnt out in my viewfinder.

How should I have handled a situation like this?

I carry a couple of screw-in ND filters for occasions like this. They're not good if you want an instant change, but if you're going to be outside in bright sun all day then it won't be a problem.

I have to usually set the shutter to 1/100 instead of 1/60th. This with the ND gets me down to 5.6 or even 4.0

Ah! OK. Thanks!

I'll go shop for the filters and next time I'll adjust the shutter -- which I am always anxious about when shooting video for some inexplicable reason ... :-)