[Marc Sabatella]

first set is full manual mode I forgot to precise, second is A mode.

When you say "full manual mode", do you mean the aperture ring was mvoed off the "A" position? Be aware that in these cases, matrix / multi-segment metering is not available, so the camera reverts to center-weighted. And that can indeed result in blown highlights similar to your first picture from the first set - that pictures looks about right for center-weighted metering. Maybe half a stop brighter than I'd expect, but not much more. No idea what happened in the picture you posted later.

[Substitute]

nope Kurt exiffs are ok we made tests at all speeds and aperture in manual mode and in A mode...
But note mine is an A not an FA though.. never had a similar problem with af lenses.
I'll try to get either an LL-60 or a Katz eye to make sure.

Yes Mark A was unlocked maybe has to do with teh metering in those cases, but it never happened before on K10D..with LL60

[tybeck]

I sold the lens to Substitute after I'd bought it off the forum here. The problems stumps me since I never had this much of an issue with it on my K10D. It did tend to overexpose, maybe by 1-1.5 stops, nothing as dramatic as posted here. The problem was aggravated in brighter light and I had to adjust the exposure accordingly. Anytime I shot under controlled conditions I didn't have an issue. For example in this post where I compared the Substitute's lens to a Vivitar 105mm Macro. I never completed the test fully, but for our purposes here we can see that the exposure from both lens was similar.

What would the differences be between the K10D's and k20D's metering? If Substitute's other lens are working fine there doesn't seem to be anything wrong with the new K20D. Odd, very odd.