Intermediate telephoto lens system

An intermediate telephoto lens system comprising a positive first lens group, and a positive second lens group, in this order from an object;

• wherein said first lens group comprises a positive first lens element having stronger positive power on the object-side surface thereof, a positive second lens element comprising a positive meniscus lens element having positive power on the object-side surface thereof, a negative third lens element comprising a negative meniscus lens element having the concave surface facing toward an image, an aperture stop, cemented lens elements comprising a negative fourth lens element having a concave surface facing toward said object and a positive fifth lens element, and a positive sixth lens element, in this order from said object;
• wherein said second lens group comprises a negative seventh lens element comprising a negative meniscus lens element having the convex surface facing toward said object, and a positive eighth lens element, in this order from said object;
• wherein upon focusing, only said first lens group moves along the optical axis;
• and
• wherein said intermediate telephoto lens system satisfies the following condition:
• (ν′1-1+ν′1-2)/2>102
• wherein
• ν′1-1 designates the dispersion ratio of said positive first lens element;
• ν′1-2 designates the dispersion ratio of said positive second lens element;
• (ν′=(nd−1)/(ng−nF)
• nd designates the refractive index of the d-line with respect to each lens element;
• ng designates the refractive index of the g-line with respect to each lens element;
• and
• nF designates the refractive index of the F-line with respect to each lens element.