Zoom lens and image projection apparatus having the same

A zoom lens comprising, in order from a front side to a rear side:

• a first lens unit having a negative refractive power;
• a second lens unit having a positive refractive power;
• a third lens unit having a positive refractive power;
• a fourth lens unit having a negative refractive power;
• a fifth lens unit;
• and
• a sixth lens unit having a positive refractive power, the sixth lens unit including at least one positive lens element,
• wherein at least four lens units move during zooming from a wide-angle end to a telephoto end and the zoom lens satisfies the following conditions:
• 0.00<o1/L1<0.38
• −0.015<θgF−(0.6438–0.001682νd)<0.04
• where o1 represents a distance from a surface vertex on the most front side of the first lens unit to a position of a principal plane on the front side, L1 represents an overall length of the first lens unit, νd represents an average Abbe number of a material of the at least one positive lens element of the sixth lens unit and is defined as νd=(nd−1)/(nF−nC), θgF represents an average partial dispersion ratio of a material of the at least one positive lens element of the sixth lens unit and is defined as θgF=(ng−nF)/(nF−nC), and ng, nd, nF, nC represent refractive indices of the material with g-, d-, F-, C-lines.