Why does Canon not make such light zoom lenses anymore ?

Peter Kwok wrote:

Canon made some very lightweight zoom lens in the past, such as the 3 versions of 28-90mm for their Rebel film cameras. Their cheap constructions kept their weight below 200g. Unlike lightweight kit lens for crop bodies, they fit your FF camera.

In this digital era where we can pixel-peep every lens before we buy, lens like these would not survive the criticism on-line. The 24-105L is considered the minimum quality for FF DSLR.

But lenses like those, and even cheaper ones in fact, are made - for crop bodies. The demand for inexpensive lenses still exists and Canon is happy to satisfy that need. They haven't been made for full frame because it was judged - rightly in my opinion - that few people would want to spend £/$3000 minimum on a full frame DSLR body then stick a cheap lens on it. The 6D, which brings full frame digital within the reach of a wider market, could lead to a change.

Also, I think many people have forgotten how cheap entry level film SLRs used to be. I remember buying a brand new Canon film SLR in the 1990s for under £200 - yes "full frame" for £200. I don't know of a source of £/$ prices for that era but Canon's Camera Museum tells me that the original Japanese market price of the 24-85 USM I mentioned in a previous post was 58,000 yen while the EOS Rebel XS was almost exactly the same price at 59,000 yen. Would you want to pay the price of a 6D (today's cheap full-frame body) for that lens?

The 24-105L has been accused by some of being not worthy of the L designation. I don't want to get too deeply into that debate, but it is a fact that its optical quality is good rather than great, it's not weatherproof, and it is one of the few IS lenses with no panning mode. And of course it is actually quite inexpensive compared with the alternatives. The OP's criticism that it's a big and heavy is fair enough, but in most respects it fills the same slot as those old mid-level USM lenses.