Originally posted by lammie200 Anyway, I am just interested if anyone has more info about installation tips.
Original Pentax screen is ca 1.33mm (measured very carefully in plastic 0.12mm bag (for protection) by micrometer, so there could be some mistake) Katzeye is for example ca 1.63mm, didn't measure ee-S, but should be slightly thinner than Katzeye. So there is difference of ca 0.3mm, (almost visible, if you put them side by side). You have to compensate this difference with the thinner shim.
Thinner screen+shim=back focus, thicker shim+screen=front focus
Focusingscreen delivers 3pcs of 0.15mm shim and 1pc of 0.25mm. The original shim in K5 or K7 is 0.40mm ( at least in mine K7 and K5).
So you can combine them. Good method is to compare focus with the original pentax shim and without any shim. If the focus changes from front to back almost symetrically, then the right new shim has to be ca one half of 0.40mm.
EDIT: I corrected myself in post #230