The 24mm is a lens that performs very well when stopped down, let down a little by being relatively soft at wider apertures, but nonetheless, a lens that is capable of producing high-quality results.
Correction in camera or in software can be used to minimise this. Chromatic aberration (CA) is the lens' inability to focus on the sensor or film all colours of visible light at the same point.
Focal length is used to determine your lens's angle of view ... Photography cheat sheet: Focal lengths explained Focal lengths below 24mm are referred to as ultra-wide-angle.
The new lenses will consist of a 10~17mm, f/3.5-4.5 fish-eye zoom, a 12~24mm, f/4 ultra-wide zoom ... For added convenience the GX-10 can be used with the all Pentax KAF2, KAF and KA mount ...