70-300 DO IS and a boat

Here we have a magnificent sunrise behind the massive 183 foot sailing yacht "Zenji"

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It is not an issue with the DO glass, rather a combination of a couple things.

First the movement of the boat, you stated the focus was on the boat and while the shutter speed was fairly high and the boat is seemingly static, though from the slight wake it seems to under power or anchored against a current. And the mast which apparently rises more than 200' above the water is not static.

Even a minor swing and swell of a couple inches in calm water at the boats hull will be magnified several hundred times or more by the time you get to the top of the mast. This 3 dimensional movement will result in a the moire like step you see in the fine lines of the rigging.

And then the moire issue that can be found on just about any dslr when viewing an image, often with the finer resolution bodies like the 5D2 this isn't often noted except at very high magnications but with the movement of the boat this effect is more obvious.

Maybe heat rising from the water, a mirage effect?

I think it is a great shot with that lens - why would you be cropping at 100% - the over all shot is fine - I wish I could get the same results with that lens ( I have one too)

It's a challenging lighting situation. I would snap a few shots in good light of something with detail and see if you can replicate the problem. My guess is that you won't be able to.

Heat Shimmer...

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