Canon 5D with 24-105mm F/4L IS @ F/16

Photograph Courtesy Bob Kulon

In early October ’05 Canon started shipping theEF 24-105mm f/4L ISlens. I had tested a pre-production sample and found it to be not only excellent optically but also a most convenient and usable lens, especially for street shooting. Two early purchasers that write for this site published reviews of the lens – one byMark Segaland the other byBill Caulfield-Browne.

I purchased a 24-105mm for myself as soon as it became available, and took it with me on a two week shoot in China later that month. I took a couple of thousand frames with it, both on the 5D and the 1Ds MKII, and I have nothing but good things to say about it.

But, as soon as I returned from China in late October I read that Canon USA had announced that there was a problem with early production lenses, and that these early lenses were being recalled for repair. You can find out more about this recall notice on theCanon USA web site.

The curious thing though is that three other members of my China expedition were also using the 24-105mm, and none of us had experienced this flare problem. I have subsequently spoken with at least a half dozen other people who own early samples of this lens (Canon stopped shipping them once the problem was discovered, and has recalled inventory from dealers), and none have seen a flare problem either.

But then on Nov 6,Bob Kulonwas one of the members of myBrickworks Workshopin Toronto, and he was using the 24-105mm on the shoot. He saw a serious flare problem on a number of his frames, and one of these is shown above. It is the green semi-circle in the upper-right of frame. The white light on the left of frame is a sunbeam coming through the roof of the abandoned factory.

Most interestingly, on Canon’s web site they state, "The flare is most obvious in the wide zoom and wide aperture settings," yet Bob’s photograph was taken at a focal length of 70mm, and an aperture of f/16.

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It’s Real

So. The problem is real after all, and is not simply due to an over-abundance of caution on Canon’s part.

If you own one of these lenses with an effected control and serial number, as shown on Canon’s information page, then you really should send the lens in for repair. To my knowledge this repair program is in effect in both the US and Canada. Elsewhere you’ll have to contact your local Canon agent or representatives, or the retailer that you purchased the lens from.

As to the actual nature of the repair, that remains a mystery, and is not mentioned on the Canon web site. Since the repairs will only start after Nov 14, I would assume that some parts are required.

I have to say that it would be reassuring if Canon would explain the nature of the repair. If it’s simply the replacement of a missing baffle, or some black flocking, that’s one thing. If it means optical disassembly, it’s another. Several readers have indicated concern at having their expensive precision lens worked on outside of the factory environment.

I intend on having my lens repaired by Canon Canada. If and as I find out more I’ll let you know.

Michael