Stacking Canon Extenders

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I have a 2x extender and am preparing to buy a 1.4x. I am debating between the old version and the II. Can the II be stacked with the older version 2x or must it be with a 2xII?

Thanks

-- Dave Rothstein (dhrothstein@aol.com), January 11, 2002

Answers

The only physically stackable combinations are 2x mk II and 1.4x Mk I or 1.4x Mk II. You must have a 2x mk II, or an extension tube to do this.

The only differences between 1.4X mk I and 1.4x mk II are that mk II has the weather-sealing and a new light-absorbing material on the inside of the barrel, which should cut flare down a little.

The differences between 2x mk I and mk II are very much greater. Mk II is an entirely new, high-performance design, which has space at the back for stacking (although the electrical contacts are not set up such that it would report the true aperture after the loss from both extenders), and the new light-absorbant material as well as the weather-sealing.

In conclusion, optically there's minimal difference between the two 1.4X extenders, so if you can find a good price on an mk I, go for it. There is, however, a much larger difference between the 2 2X extenders, and it might be worth considering the upgrade.

-- Isaac Sibson (isibson@hotmail.com), January 12, 2002.


"however, a much larger difference between the 2 2X extenders"

Isaac - is this from experience or theory? My personal experience is that the optical performance of the new 2x II and old 2x is very close. I really didn't see any difference when I tested them on my lenses.

-- Bob Atkins (bobatkins@hotmail.com), January 12, 2002.


This is, admittedly, from theory. I would bow to your much greater experience, and actually having used the items in questions. I have only ever handled the 1.4X TCs (both versions), and own a mk I. I am keen to get a 2x, once I have my EOS 3, as that will allow me an AF 600mm F8 IS, and I would also like to be able to experiment with stacking the two extenders, without using tubes. Everything I had heard pointed to the 2x mk II being a reasonable improvement over the mk I, with very little difference between the 2 1.4X TCs.

However, I'm interested to hear you say that there's little difference Bob....Which lenses have you used it on? Does one work better than the other with the 300 F4L IS (I don't envisage using TCs much on my 70-200 F4L)?

-- Isaac Sibson (isibson@hotmail.com), January 12, 2002.


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