Televue Dioptrx and your Pentax XW40 and XW30

This is a photo essay with the text in the photos. I would add, that the dioptrx, like any astigmatism corrector, has to be held at the right angle, relative to the eye. Therefore, the eyepiece must be rotated in the diagonal or focus tube to get the right correction for you. Your own prescription determines which Televue dioptrx you buy.

I note also that to get the metal lip to screw over the dioptrx, the rotating body of the eyepiece must be high enough.