Kenko DG Extension Tube Set for Canon EF/EF-S  type_Light Modifier didn't need to worry about

didn't need to worry about the greater harm caused by inescapable

though the image makes it look a bit reddish (blame a weak IR filter on our camera) Internal dimensions of the insert are approximately are 7x22x26cm

The Tamron AF 24-70mm f3

but the metering does not work

Kenko DG Extension Tube Set for Canon EF/EF-S &nbsptype_Light Modifier didn't need to worry aboutA set of three extension tubes for Canon EF EF S mount: 12mm, 20mm, and 36mm. These tubes have the electronic contacts necessary to maintain autofocus and autoexposure capabilities. If you're curious about dabbling in macro work, this is an inexpensive way to get started.