Question on Teleconverters and Extension Tubes

[Ariel Matias]

Hi,

I understood that TLCs are used to extend the range of the zoom lenses while the ETubes are used to magnify the image.

But isn't it that the end results are the same? When using 2x teleconverters for example, the zoom range doubles and therefore the image magnifies. I've seen some online forums that discussed this issue and some prefer to use the ET for bird photography while others prefer the TLCs.

May I know your personal opinion on this, please?

Thanks and regards,
Ariel

[Bobby Kintanar]

Ariel, basically a Teleconverter will magnify the image gathered by a lens to a given magnification (by its rating) So a 400mm f/5.6 lens will become a 560mm f/7.84 (f/8) lens when mated with a 1.4x TC. A 2X TC will double both the focal length and aperture, etc.

An Extension Tube, on the other hand, allows a user to lessen the Minimum Focusing Distance of a given lens, thereby allowing the user to go nearer the subject and effectively get a larger image - but there is no real, optical, magnification involved as in Teleconverters. Hence the 400 mm F/5.6 will still be a 400mm but the effective aperture will no longer be F/5.6 - but you can now move in closer to the subject.

Light loss will result in a dimmer photo, depending on the rating of the Extension Tube, so you have to compensate accordingly, and you will lose the ability to focus to infinity as well. For a more detailed discussion, see this:

www.mir.com.my/rb/photography/hardwares/classics/nikonf2/macro/index1.htm

Hope this helps.