Extension Tubes or Canon Close-up Lens Adapter?

[Tony Printezis]

I had asked the same question here. I'm personally leaning towards the extension tubes given that I can use them on any lens, irrespective of filter size.


Tony

[George Slusher]

I'm personally leaning towards the extension tubes given that I can use them on any lens, irrespective of filter size.

You can do the same thing with step-up rings, which are cheap. I have a Canon 77mm 500D, which I can use on any telephoto lens I have, includingmy 100mm f/2.8 Macro. (The 500D is not designed for lenses under 70mm focal length. For those, use the 250D.) I mostly carry it to use on my 100-400mm L IS, instead of carrying the Macro lens.


Some other considerations:

1. Using extension tubes will lose light and lead to a slower shutter speed, wider aperture, and/or higher ISO. Extension tubes work by moving the lens further away from the sensor. That makes the image circle of the lens larger, spreading the same light over a wider area, so less light falls on any particular section of the sensor. (Calculating the exposure correction for manual exposures used to require at least an MS in math, but modern auto exposure pretty much takes care of it.)
2. Depending upon the particular extension tube you use, you may lose auto exposure and auto focus. Don't even consider the really cheap extension tubes for that reason. Get the Canon or Kenko DG tubes.
3. As others said, extension tubes don't do much with longer focal-length lenses. Using longer extension tubes will make the light loss even greater and greatly reduce the furthest focal point.
4. For serious work, don't bother with cheap "close-up lenses," either, though they work in a pinch and are cheap. The Canon 500D, on the other hand, is a 2-element lens that corrects for a lot of distortion.
5. The working distance range with the Canon 500D is very narrow. You can change the magnification with a zoom lens, but the working distance doesn't change very much.