Teleconverter decision

[rcd7112]

I have decided to purchase a 1.4 teleconverter to use with my Canon XT and the lens I have-70-2004L and a EF 75-300 F4. My question is, canon sells theirs for $279. while both Sigma and Tamarron sells theirs for $189. Will the Sigma and Tamarron work as well as the canon.? Also I assume a teleconverter will work with any canon lense that works with my XT.
Canon or Sigma/Tamarron and save $90.00
I appreciate help in making this decision.

[CaptainTom]

NOt as simple a question as it seems.
The Tamron and Sigma are tauted to be as good as the Canon.
Check on the respective web sites to see if the teleconverter is compatible with your lenses.

[gsdpic]

You can't assume the teleconverter will work with any lens. I believe that the little metal flange on the lens mount is slightly different for lenses accept a teleconverter. I have a sigma 1.4x TC and a rather old example of the EF 75-300 lens and the TC will not physically mount on that lens (nor will it mount on any EF-S lens). I have used the 1.4x tc with the sigma 100-300 F4 lens and have been pleased with the results, though have not had a chance to compare to a canon TC, and not used it on any other len, though I'd expect it to work on the 70-200F4L.

[johnastovall]

Originally Posted by rcd7112

I have decided to purchase a 1.4 teleconverter to use with my Canon XT and the lens I have-70-2004L and a EF 75-300 F4. My question is, canon sells theirs for $279. while both Sigma and Tamarron sells theirs for $189. Will the Sigma and Tamarron work as well as the canon.? Also I assume a teleconverter will work with any canon lense that works with my XT.
Canon or Sigma/Tamarron and save $90.00
I appreciate help in making this decision.

No, the Canon converters only work with some not all Canon lenses over 135mm focal lenght.

Canon 1.4 teleconverter lenses it will work with.

I got a Canon for the simple reason if there's a problem it's Canon's problem since I use only Canon lenses. There are MTF charts for it with the various lenses it works with so I can have some idea of the theortical preformance of it and any lens combination.

[lhdvies]

I have both canon 1.4II and the Tamron 1.4 SP. They work equally well on my 70-200f/4 LIS(assume the non IS would be the same),I don't know about the 70-300, but don't believe it accepts the 1.4.(not sure though) The only advantage the Canon has over the Tamron1.4 SP is weather sealing(when used with a weather sealed lens & camera). I find IQ to be equal for both on the sames lenses.

[3n-Out]

Check this out. Just happened to run across is after reading your post

http://www.usa.canon.com/dlc/control...&articleID=266

[KdLaneJr]

Originally Posted by johnastovall

No, the Canon converters only work with some not all Canon lenses over 135mm focal lenght.

Canon 1.4 teleconverter lenses it will work with.

I got a Canon for the simple reason if there's a problem it's Canon's problem since I use only Canon lenses. There are MTF charts for it with the various lenses it works with so I can have some idea of the theortical preformance of it and any lens combination.

Adding Sigma's teleconverter site.

Also Canon has a nice little discussion about teleconverters here.

and.., I can tell you from experience that Canon's 1.4x mk II extender will not fit Sigma's 80-400 OS or the 50-500.


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