well a lense for digital is basicly the same as a lense for analog. the key diffrence between them is the medium where the image is captured. For analog this is Film. For digital it is a CCD (Charged Cuppled Device.)

Edit: Ah... Mom just informed me of an article that tells how digital lenses are not as good as analog lenses because the CCD cant capture that dense an image. This makes sense to me. It lowers the total cost for the camera by useing a lower quality lens.

Current CCD chips are tiny compared to a negative which i find odd. Wouldnt it be more advantageous to focus the image on a much larger area but keep the pixel density? One would think so.

One interesting tidbit ive found working with digital video, Pixel Shapes.

One would assume that a pixel is square in all forms. However on NTSC televisions they are ever so slightly rectangular. And in other contries... well thy run the gammot from square to a really exagerated rectangle. Computer screens are square across the board.