Leica 135mm F4.5 Hektor This lens is a fine performer.  Often overlooked for the Elmar and Tele-Elmar of the same focal lengths, excellent examples can be purchased for a quarter of the price on the used market.  This lens is a good choice for those wishing to add this focal length to their Leica kit with minimal cost.  I like this lens and at the current prices, you simply can't beat it.  The Hektor designation was originally used for Leicas high speed/performance lenses.  Named after Max Berek's fastest dog back in 1933 and originally introduced in a screw mount, the M mount version was later introduced in 1954.  This lens configuration was so good that it stayed the same for 33 years!  I have shot this lens next to my Tele-Elmar of the same focal length with excellent results.  The difference is hardly noticeable and most people will not be able to tell the difference in good examples, so give this lens a try!   135mm F4.5 Hektor 1954-1960 Type 1&2  SN#1,124,000-1,827,000 Finish Chrome Mount Rigid Lens Elements 4 in 3 Groups Filter Size Type 1 36m - Type 2 39mm Apertures F4.5-F32 Angle of View 18 Degrees Minimum Focus Distance 1.5 Meters Units Produced N/A Weight 440 Grams The type 1 had a 36mm filter size while the type 2 has the much preferred 39mm filter size.  A convenient tripod socket was attached to this lens.  Both versions also had removeable optical groups for use with the Visoflex system.