No, I havent succumbed and bought an LX yet and know nothing about screens, so am posting this for a friend who needs some advice. Thanks
"The Pentax User Magazine site "http://www.pentaxuser.co.uk/index.html" has for sale under camera accessories "Beattie" replacement focusing screens for the Z1/Z1P, MX & LX. Does anyone have any experience of these. I do a lot of available light shooting with Pentax MX & Z1 and any extra focusing help would be usefull as the Z1 is dim, though the MX is allready very bright. I mostly use fast lenses for this 1.4-2.8 but use normal 3.4-4.5 zooms the rest of the time. One thing I'm concerned about is that If I get one with a focusing aid for the Z1 that it would interfere with the autofocus ? They also do a clear one. Anyone had any experience with them ?"

