Lens production run numbers - What does sequence mean?

[savas_kyprianides]

It occured to me to wonder if these numbers mean an entire run of several hundred or

thousand - all bearing the same number. Or, each one bearing an incremental increase

much like a serial number. I see mention of Canon production run numbers imprinted on

the sensor-facing side of the lens, specifically regarding 24-105 L IS lenses. Lenses after

UT999 are supposed to have had a flare problem fixed. One person complained of flare

problems with his lens having number UT1004. I own the same model lens bearing

number UT1101. Therefore, my inquiry as to what the numbering scheme means; multiple

lenses all bearing a number, or lenses being numbered individually in sequence.

[robin_sibson1]

UT1101 or whatever is a combined factory code, year-and-month-of-production code and batch number, and will be common to many individual lenses. Also, as far as glass is concerned, it now appears only on L-series lenses and few other pro items such as the Extenders and the non-L TS lenses.

 

All glass items have a serial number unique to the individual item. On pro items this is usually a number of up to six digits and is clearly visible and legible. On non-pro items it is a long string of digits that may finish with a letter, and is printed in tiny hard to read characters on the back face of the lens barrel.

[ketil_johansen1]

See http://www.a1.nl/phomepag/markerink/eos_age.htm

 

Ketil

[gary_jean1]

http://www.the-digital-picture.com/Canon-Lenses/Canon-Lens-Aging.aspx

[luis alvarez torres]

Oh my! in my case my 17-35L is UK1001 it means that I just bought a 9 y.o. lens!