 Rhonda Journeay |
Using an extension tube I was just testing my new Canon EF 25mm extension tube attached to my f/2.8 100mm macro lens (all with 20D camera). The first extension tube I received, the focus did not work. This is the replacement and now the focus works fine, but I can't set an aperture value. It must be the extension tube since all of my lenses by themselves have no aperture setting problems. Anyone ever experience this before? Please help :-(
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Michael H. Cothran |
I'm not a Canon shooter, but I would think that the "EF" extension tubes would have all the necessary contacts to work in conjunction with your 20D. Look at your tube (front and back) and your lens (back only). The contacts should look the same on both. It would make absolutely no sense otherwise, since, as you pointed out, you have no other way of setting your aperture other than on the camera body. I'd contact Canon directly, and inquire. FYI - your 25mm extension tube connected to a 100mm macro lens will yield a 1:4 magnification ratio when the lens is focused at infinity. Focused at the lens' closest (1:1), you will achieve a 1.25:1 ratio, or 25% larger than life size. Should be fun to use. Good Luck.
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Jon Close |
By "autofocus did not work," do you mean that the lens tried to AF but failed to lock focus and quit? This is normal when using extension tubes because the increased distance means less light getting to the AF sensors. The instructions recommend manual focus when using the extension tube. Re - not being able to set the aperture:
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Rhonda Journeay |
Michael & Jon, thanks so much for your advice. I tried everything and the aperture value is still not working, so back it goes. I'll just have to buy something in person next time so I can test it on the spot.
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