EF-S on a Full Frame Body with extention tube?

[alankozub]

Maybe it is a dumb question but...Can a ef-s lens be used on a full frame eos body with an extention tube between

them? And if so what would be the advantages and disadvantages?

[richterjw]

<p>It wouldn't have a large enough image circle to cover the full frame camera. JR</p>

[tommyinca]

<p>You could. In a reversed way as in moving a slide projector back to increase the projected image size, when you add extension, you actually increase the image circle. The problem is, you trade the increase image size with maximum focus distant. This mean, only near macro distant subject will be able to put in focus.</p>

<p>Another way is to use a teleconverter but that open a different can of of worm.</p>

[JDMvW]

<p>Many third-party "digital only" (meaning APS-C only, the equivalent of EF-S in the Canon line), will in fact mount directly and easily on 35mm sensor Canon bodies. You do need to watch out for rear projections and the like that might jam the mirror, for example. I use a $30 EOS 650 film camera (the first EOS camera) to try out such lenses and other lenses with adapters since I'd lot rather replace a $30 camera body than my 5D.<br>

However, one reason EF-S lenses and their kin are less expensive is as Jeremy says, they are designed to cover a smaller image circle in the focus plane.<br>

Here's a Sigma 10-20mm digital-only lens on a "full-frame" 5D at 20mm showing that it does not cover the full image size. While an extension tube would probably mount an EF-S lens it would only 1) be for macro and 2) would very likely still vignette like this example.</p><div></div>

[James G. Dainis]

If you take a camera lens and project the image circle onto a sheet of paper, you can see that the image circle gets larger as you move the lens further away from the camera. If the camera will take an extension tube then you won't get vignetting but you could only focus on things a few inches in front of the lens. Good for macro shots but not much else.