Originally posted by stevebrot
Note that I have not personally tried my Type-S yet with slower lenses or in stop-down mode to see if the metering is appropriate.
Now this is sort of interesting. I just put my 18-55 on the K-3 with Type-S installed to see how it meters at 55mm (f/5.6 to the meter cells). How does 2 stops underexposed in moderately dim light sound? The issue appears to be the AF frame option that I ordered. Rather than the fine black lines of the stock screen, focusingscreen.com appears to use some sort of laser scribing that produces a very
bright clear set of lines. The emphasis is on the word BRIGHT. That brightness is present even when the frame is fairly dim and appears to be biasing the meter. At least, I think that is what is happening. Not having the non-scribed version, it is hard to tell.
As a result, and lacking a fully detailed assessment, I have to give a tentative and highly qualified
thumbs down to the focusingscreen.com Type-S screen with scribed AF lines on the K-3 for slower "A" contact lenses and for stop-down metering with any lens.

I can't say how the K-50 might handle it since the two cameras have a different metering system.
More to come once I have a chance to fully characterize this issue.
Steve