Re: When do they make lenses? (A bit long)

[Bruce Rubenstein]

"Make" covers a lot of ground. The term assemble is closer to what you are asking. A company has to balance how much they want to tie up in stock vs. costs for starting and stopping production. (I once read that Minolta came up with a figure of how many cameras they could sell of a particular model, make them all and change models when they ran out of stock.) Companies try to optimize inventory turnover and cash flow so things get very complex. It's much more expensive to stock completed assemblies than parts. Some parts are common across lenses and kept in stock. Some parts may have high setup costs, but low per unit cost. (Stamped parts are like this - once the die is set in the press and everything is adjusted it doesn't cost much more to make 50,000 parts than 10,000 parts.) Lens elements are at the other end of the spectrum. Some parts are bought from outside suppliers.
It's pretty safe to assume that high production lenses have scheduled assembly runs (parts have to be made/ordered/pulled from stock) and low production lenses are assemble on an as need, small batch basis. The manual that gets stuffed in the box is just another "part", and they probably hate to throw parts away even if they're a little old.

BR