No, using an extension tube won't change the focal length of the lens. It
simply allows one to get a part of the 28mm-perspective image to fill the
frame, but only for subjects significantly closer than normal. Therefore,
you still get the same perspective, but only for really close subjects.
This focus distance is a problem however. On some lenses, like my 28-200mm
zoom, if I try to use even the thinnest extension tube, the subject must be
closer to the camera body than the outside surface of the front element
allows. This is why I need a new lens to even play with this perspective on
macro subjects. Second, it makes it extremely difficult to get light onto
the camera-facing surface of the subject.
FYI, longer focal length lenses allow a greater working distance between
the camera and the subject, therefore making lighting way easier. However,
they also significantly affect the background. When you get up around
200mm, the subjects tend to appear flat and are isolated in crisp focus
against a mottled, color-washed background. With shorter lenses, you start
to get some details in the background (in addition to getting more of the
background in the image), which can be useful for giving the viewer a sense
of where the subject was.
hope that helps,
patbob ([EMAIL PROTECTED] [EMAIL PROTECTED])
> >I have the M28/3.5 and the FA28/2.8 and neither of them gets
> particularly
> >close
> >but I just use an extension tube and find that works well.
> >> I've been thinking of getting a wide angle lens (28mm or less) I
> >>can use
> >>for macro shots. Anyone have any recommendations for what
> would be a good
> >>choice?
> Does using an extension tube change the angle of view? (does
> it still have
> a 28mm perspective?)
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