The 2.8 gang. These are SHARP lenses. The 24-70 has been on more than anything else since I got it. For DC trip, I took only it and the tiny 50mm 1.4 in my pocket (for when the light completely took down its tent and left). Most of the shots in this gallery http://www.pbase.com/lougr/washdc are with this lens including many of the low light ones. The 14-24 on D700 outwides the 10-20 on D300.