Zoom lens and photographing apparatus having it

A zoom lens comprising the following lens components in the order named from the object side:

• a front lens component of a negative optical power in the entire zoom range, said front lens component having a first lens unit of a positive optical power and a second lens unit of a negative optical power in the order named from the object side;
• and
• a rear lens component of a positive optical power in the entire zoom range, said rear lens component having a third lens unit of a positive optical power and a fourth lens unit of a positive optical power in the order named from the object side;
• said zoom lens varying a spacing between principal points of said front lens component and rear lens component by varying a spacing between said first lens unit and said second lens unit and a spacing between said third lens unit and said fourth lens unit, in order to effect zooming,
• wherein said fourth lens unit changes its moving direction during zooming from the wide-angle end to the telephoto end,
• wherein said first lens unit consists of a lens element of a positive optical power, and
• wherein said third lens unit has a lens element of a positive optical power and a lens element of a negative optical power.

A zoom lens comprising the following lens components in the order named from the object side:

• a front lens component of a negative optical power in the entire zoom range, said front lens component having a first lens unit of a positive optical power and a second lens unit of a negative optical power in the order named from the object side;
• and
• a rear lens component of a positive optical power in the entire zoom range, said rear lens component having a third lens unit of a positive optical power and a fourth lens unit of a positive optical power in the order named from the object side;
• said zoom lens varying a spacing between principal points of said front lens component and rear lens component by varying a spacing between said first lens unit and said second lens unit and a spacing between said third lens unit and said fourth lens unit, in order to effect zooming,
• wherein said fourth lens unit changes its moving direction during zooming from the wide-angle end to the telephoto end,
• wherein said zoom lens further comprises a stop, which moves along the optical axis together with said third lens unit during zooming, on the object side of said third lens unit, and
• wherein said fourth lens unit consists of a lens member of a positive refractive power.

A zoom lens comprising the following lens components in the order named from the object side:

• a front lens component of a negative optical power in the entire zoom range, said front lens component having a first lens unit of a positive optical power and a second lens unit of a negative optical power in the order named from the object side;
• and
• a rear lens component of a positive optical power in the entire zoom range, said rear lens component having a third lens unit of a positive optical power and a fourth lens unit of a positive optical power in the order named from the object side;
• said zoom lens varying a spacing between principal points of said front lens component and rear lens component by varying a spacing between said first lens unit and said second lens unit and a spacing between said third lens unit and said fourth lens unit, in order to effect zooming,
• wherein said second lens unit changes its moving direction during zooming from the wide-angle end to the telephoto end,
• wherein the following condition is satisfied:
• 0.7<fRa/fRb<1.5
• where fRa is a focal length of said third lens unit and fRb is a focal length of said fourth lens unit, and
• wherein while zooming from the wide-angle end to the telephoto end, a spacing between said first lens unit and said fourth lens unit changes nonlinearly.

A zoom lens comprising the following lens components in the order named from the object side:

• a front lens component of a negative optical power in the entire zoom range, said front lens component having a first lens unit of a positive optical power and a second lens unit of a negative optical power in the order named from the object side, all lens elements having negative optical power included in the second lens unit being structured such that the optical power of the image-side surface is larger than the optical power of the object-side surface;
• a rear lens component of a positive optical power in the entire zoom range, said rear lens component having a third lens unit of a positive optical power and a fourth lens unit of a positive optical power in the order named from the object side;
• said zoom lens varying a spacing between principal points of said front lens component and said rear lens component by varying a spacing between said first lens unit and said second lens unit and a spacing between said third lens unit and said fourth lens unit, in order to effect zooming,
• wherein said second lens unit changes its moving direction during zooming from the wide-angle end to the telephoto end, and
• wherein while zooming, at least one of said first lens unit and said third lens unit moves.