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Canon MKIII convertors experiences please (1 Viewer)

Richard Ford

BF Member
I use Canon 90D and am looking to hear about direct experiences using the below lenses and converters.

I'm wary of convertors but I hear the new MKIII have less issues with IQ and AF than previous models.

Canon 500mm f4 MKI plus 1.4x mkiii seems to have a good rep for results. Any idea how those results compare with Canon 400mm f2.8 MKI and 2x MKIII obviously 800mm f5.6 sounds lovely on paper but I'd rather not sacrifice IQ and AF.

Both combos would be similarly priced on the second hand market.

If this is covered elsewhere please point me to the thread.

Cheers
Rich
 

MJN

Well-known member
What are the issues with the previous model convertors (mk2) ?

I had both 1.4x and 2x for many years and wasn't aware of any issues concerning IQ or AF when used with L glass.

In my opinion the Mk3 convertors are not particularly better optically but the 2x mk3 certainly performed better than the 2x mk2 for BIF when used with a 300 2.8 lens.
The 1.4x, I didn't notice any difference between the two models.

Cheers.
 

Manolito

Active member
You shouldn't have any problem Mk II teleconverters. The MkIII have better communication between the lens (newer lenses) and the camera and AF speed (specially 2X). With a 500 Mk I you wouldn't see any noticeable difference between MK II and III teleconverters.
 

MJN

Well-known member
Do you have an option to borrow some mk3 convertors off a mate to try them?

It may be worth a try particularly with the pixel packed sensor of the 90D which also has a fairly basic af system.

Using a 90D + 500f4 mk1 + a 2X mk3 may require rock solid support + good conditions + good technique + good processing for it to shine.

Do let us know how it goes.
 

Richard Ford

BF Member
Thanks all, really useful comments. If its genuinely the case that I have nothing to gain between MKII and MKIII convertors when using on a Canon EF 500mm f/4 L IS USM then I can save a few £ there so thanks. I've read that IQ is better around the corners and edges on MKIII 2x and new versions conbate CA and other issues. I just wonder how noticable and if its largely irrelevant on a MKI lens. Looking for the best performance I can get but happy to save a few quid if the MKIII's simply won't offer more on this combo. Cheers.
 

Richard Ford

BF Member
Additionally anyone used convertors on the Canon EF 400mm f2.8 L IS USM? A nice lens to have, but weight may also be an issue. Thanks for any input. I'm lucky to be in a position to upgrade my gear at the moment so I'm looking at views on these lenses and convertors specificall for wildlife use. 👍👍
 

Roy C

Occasional bird snapper
I have tried the 1.4x MkIII and cannot see any difference between it and the MkII, either in IQ or focus speed. The 2x is a different story though with the MkIII being a fair bit better IMO.
 

Tully

Well-known member
Thanks all, really useful comments. If its genuinely the case that I have nothing to gain between MKII and MKIII convertors when using on a Canon EF 500mm f/4 L IS USM then I can save a few £ there so thanks. I've read that IQ is better around the corners and edges on MKIII 2x and new versions conbate CA and other issues. I just wonder how noticable and if its largely irrelevant on a MKI lens. Looking for the best performance I can get but happy to save a few quid if the MKIII's simply won't offer more on this combo. Cheers.

Richard my experience with that lens was that the quality dropped off significantly with the older 2x. I got rid of it quickly. The 1.4 x was fine and lived on it.

When I upgraded to the Mk II 500, I found the Mk III 2x worked well with it.

N
 

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