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Old 29-06-2007, 01:37 PM
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Stephen65
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Join Date: May 2007
Location: Melbourne
Posts: 358
Just musing on this - theoretically if you used a filter that excluded everything but the exact wavelength you were focusing to then you could get exact focus on that wavelength despite chromatic aberration.

But...that would have be a very narrow band filter and you'd be excluding all the light between the wavelengths you chose to image so you would probably end up with a very dim image. On the other hand, if you made the filters a bit wider to let in more light around each wavelength then the range of wavelengths you allowed in wouldn't have the exact same focal lengths either so you would be trading away sharpness of focusing for brightness.
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