I picked up this handy hack from a review of these macro extension tubes. (For some reason, these particular tubes are not available from Amazon.com, only Amazon.co.uk. That’s a pity, because they only cost £6, far less than Kenko and much less than a macro lens.)
- Set your aperture.
- Press the lens release button to remove your lens.
- Hold the button down while you put the extension tube on the camera body. When it clicks into place, you can release the button.
- Click the lens into place on the tube.
Very easy. Not rocket science. You get deeper depth of field, which is a good thing because focusing with macro tubes is not a lot of fun if your hands aren’t perfectly steady. These tubes have no electronic connections, so there is no autofocus.
This trick works with my Canon Rebel XSi (450D). I haven’t tried it with other camera brands.