# Extension tubes.



## LightSpeed (Dec 1, 2010)

Say one has a 100mm extension tube and attaches it to a lens with no aperture ring. How would one then change aperture settings? The extension tubes have no circuitry, therefore no auto focus but focusing isn't the issue. Nor are shutter settings. Only the aperture seems to be the complication on a lens with no aperture ring.  Is there a work around?


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## Edsport (Dec 1, 2010)

What you do is set the aperture that you want then press the DOF (depth of field) button and while keeping in on the button unscrew your lens. This is done with the camera turned on. Now use your extensions. You can get extension rings that has circuitry but more expensive...


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## Enough Already (Dec 1, 2010)

Edsport said:


> What you do is set the aperture that you want then press the DOF (depth of field) button and while keeping in on the button unscrew your lens. This is done with the camera turned on. Now use your extensions. You can get extension rings that has circuitry but more expensive...



The DOF is totally different with extension tubes. AFAIK, with no aperture ring, Im pretty sure your aperture will be as small as it goes. You will not be able to control it at all. I have a fully manual 50mm (aperture and focus) and a 70-300 with an aperture ring. Without the lens control from the camera, even full auto lenses become fully manual. And with the aperture small, you will have a very dark viewfinder in low light which will make focusing difficult.


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## Overread (Dec 1, 2010)

The important question is what camera brand you are working with - the example of the depth of field preview button trick above for example only works with Canon lenses and camera bodies and not with Nikon - whilst the answer below about the aperture of the lens always being the smallest applies to nikon - whereas the default for canon is having the aperture blades wide open.

So first up is what your brand is


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## Edsport (Dec 2, 2010)

I've never used nikon so i can't say if my trick works with those cameras but yup, it do work with my canon camera and lenses...


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