Tubes or TC?

[PhatheadWRX]

I'm looking to get a bit more magnification out of my 100 macro.

Should I get tubes or a kenko 1.4 teleconverter.

I know the tubes will get me more magnification (full set closer to 2:1), but won't they greatly affect the distance between the FE and subject?

If the 100 is 119mm and MFD is 300mm, adding 68mm of tubes = 187mm of lens = 113 mm to subject (~5 in), correct?

The 1.4 shouldn't affect the distance to subject as much, correct?

Also, the plus of the TC is that I could mount it to other lenses (70-300)

Thoughts??

[gjl711]

Tubes will affect the working distance allowing you to focus closer to the subject thus high magnification. The advantage with tubes is that there are no optical elements thus minimal impact to image quality. A TC will not change working distance but with the added optical elements there is a hit to image quality. You also have to be a bit careful as not all TCs will work on the 100 I believe. The advantage is that a TC can be used for non-macro applications a well.

[PhatheadWRX]

I'm pretty positive that the Kenko 1.4x 300 Pro will work with the 100 macro directly, and IMHO the IQ hit is very minimal, if noticable at all.

[gjl711]

I'm pretty positive that the Kenko 1.4x 300 Pro will work with the 100 macro directly, and IMHO the IQ hit is very minimal, if noticable at all.
Kenko will, I think it's the Canon that wont.