Canon x1.4 converters

[John Cooper]

I have the original Canon x1.4 converter and use it at times with my EF100-400 L lens. Now there is the x1.4 11 and x1.4 111 models.
Can anyone enlighten me please what the main difference is between the 3 models and which is recommended for the EF 100-400 and 70-200 F4 IS lens.

[Jon Rista]

I can't say much about the Mark I versions of Canon's TCs. The difference between the Mark II and Mark III versions is edge and corner performance. Center performance is similar, maybe a little better on the Mark IIIs. Edge and corner performance is improved considerably on the Mark IIIs over the Mark IIs. Distortion and CA are supposed to be better controlled as well. I've used the Mark II and III 2x TC, and the difference seemed very noticeable in the corners. I have only ever used the Mark III 1.4x TC, so I can't say explicitly if what the reviews say about it are true or not, but I'd offer the 1.4x III would perform better than the 2x III.

[John Cooper]

I can't say much about the Mark I versions of Canon's TCs. The difference between the Mark II and Mark III versions is edge and corner performance. Center performance is similar, maybe a little better on the Mark IIIs. Edge and corner performance is improved considerably on the Mark IIIs over the Mark IIs. Distortion and CA are supposed to be better controlled as well. I've used the Mark II and III 2x TC, and the difference seemed very noticeable in the corners. I have only ever used the Mark III 1.4x TC, so I can't say explicitly if what the reviews say about it are true or not, but I'd offer the 1.4x III would perform better than the 2x III.

Many thanks Jon for your comments. I have heard that the later converters (I guess the 11 and 111) were designed for the latest big guns such as 500mm & 600mm IS lenses. So I'm not sure what difference it would make to my 2 zooms mentioned above.

[John Cooper]

Hi John - the MkIII-TC's are optimised for the new Supertele-II-Lens generation: in addition to magnifying they assist in focus performance. They can however be used on other lenses as well.
The only improvement you will get with your lenses is as mentioned above (distortion/CA/corners). I personally think you won't gain much.

Many thanks Peter - thats what I was thinking also.

[arash_hazeghi]

In your case the bottleneck in IQ is the lens not the TC, so I don't think you will see a difference.

[John Cooper]

In your case the bottleneck in IQ is the lens not the TC, so I don't think you will see a difference.

Thank you Arash, all the comments are suggesting the same thing - guess I can save my dollars and stick with what I have

[Richard Mc Donald]

Just adding my 2 cents worth here in case others may come looking for information on the Canon 1.4X Extenders and their 800L f/5.6 lens - both the Mark II and Marl III offer very similair slow focusing, image quality on with the III is slightly better than the II.

Richard