Well, sort of.
A lens, converter, or whatever, is really just a set of glass pieces held together in a metal cylinder. The allignment, color, or surface of the glass in the cylinder will affect the light that hits your CCD’s, and therefore, alter your image.
The thing to remember is that glass, like diamonds, comes in varying degrees of quality. On the surface, glass might look the some on a HD lens or converter as it would on a SD lens or converter, but if you could take a closer look, you would see that glass varies wildly, and this sffects the quality of yur final product.
A lens made for High Def cameras will undoubtedly use a superior quality glass, and give you a better picture, even on a SD camera. (Note that an HD lens won’t "convert" a Standard camera to High Def. You’re limited by your CCD in terms of picture resolution.) So yes, there are varying degrees of lenses. As a rule of thumb, avoid buying the cheaper, less known brands for your lenses and converters if you can avoid it. Stick with proven performers who use the best glass quality.
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