135/2.5 (later SMC version--hard to distinguish and to find) is the same as K lens and has a great reputation--the earlier one isn't as good at least at wide stops.
The version I shows 8, 16, 22 as depth of field marks while version II shows 4, 8, 16, 22. So simply look for the lens that has a single "4" between the two symetrical "8".
Andre
