Though the S2 / S3 / S5 IS is capable of 12x optical telephoto, or 432mm, there will be the occasion where even greater power is desired.  We've tested several teleconverters and the results are presented here.  The converters range from 1.5x to 1.7x.  To calculate the effect of a teleconverter, simple multiply the power of the converter by the focal length of the S2s lens.  For example, the S2 at full tele is 432mm.  Multiply 432mm x 1.5x = 648mm focal length.  The exif information from the camera records the focal length as 6.mm to 72.mm.  To convert to 35mm equivalent, multiply this number by 6.

The Canon S2 / S3 / S5 IS samples below were taken using the Lensmate 52mm and 58mm adapters and the teleconverters described.

The first image of the pair is the converter with the camera at full telephoto zoom, and the second image shows that point at which vignetting begins to appear. If the lens was zoomed back further toward the wide setting, the corners would darken and the image would eventually become circular.

S2 IS with no converter

Click on any thumb to see full size image.

Zoomed to max telephoto
432mm

Zoomed back to the point at which
vignetting begins.
Focal length 256mm

Zoomed back to the point at which
vignetting begins.
Focal length 202mm

Zoomed back to the point at which
vignetting begins.
Focal length 252mm

Zoomed back to the point at which
vignetting begins.
Focal length 217mm

Zoomed back to the point at which
vignetting begins.
Focal length 611mm