Sigma Macro 180mm f2.8 OS Canon TC modification

[Jappe]

I just bought Sigma Macro 180mm F2.8 EX DG OS HSM and I noticed that Canon TC's cannot be used with it. Looks that Sigma has just added additional (too long) collar behind the rear lens. That collar will prevent use of Canon TC's. If collar would be just 1-2 mm shorter Canon TC's could be used.

Has anyone tried to cut that collar little bit shorter? I removed bayonet of the Sigma but I couldn't figure out how that collar is mounted. Maybe it has only threads that will keep it around the rear lens mount. That collar seems to be made of plastic so I believe that it is not the actual mount for the rear lens.

Surely modification can void warranty, but lets not care about that ;D

 

[Jappe]

I tried to modify Sigma, but it was not working easily. :-X

I decided to see if TC could be modified...

I removed rubber collar from Canon TC's outer most lens and I cut outer lens holder tube 0,5mm shorter. Now Canon TC fits to Sigma 180 mm OS macro and it works with it perfectly.

 

[chrysoberyl]

I just got a Sigma 180mm 2.8 and my Canon 2X TC III does not fit. Is that the same TC you modified? Does it AF with the 2X TC? How did you cut the tube?

 

[Deleted member 91053]

I modified a cheap extension tube to allow the use of extenders on any Canon EOS mount lens. It completely eliminates the problem of the lens rear elements fouling the front element of the extender. You will loose infinty focus but that is hardly a problem on a Macro lens!
For reference the extension tube is 13mm long. If you look at the one on the right you can see that I modified the anti reflection screen with a Stanley Knife. Cheap - simple and it works!

 

[chrysoberyl]

Thanks, Johnf3f, I have gone that route with the Canon 12mm extension tube, but infinity focus and AF are lost. I want the flexibility of going from macro to tele without fiddling. I like what Jappe did, but before a start modifying, I would like to know whether the Sigma 180 2.8 + Canon TC III combination will AF.

 

[Deleted member 91053]

Thanks, Johnf3f, I have gone that route with the Canon 12mm extension tube, but infinity focus and AF are lost. I want the flexibility of going from macro to tele without fiddling. I like what Jappe did, but before a start modifying, I would like to know whether the Sigma 180 2.8 + Canon TC III combination will AF.

Don't understand why you lost AF! The extension tube should just relay the electrical signals and no functionality should be lost, though infinity focus would go.
I am afraid there is no solution other than modifying your lens/extender at your own risk! Though you could try the old Kenko 1.5 (Note 1.5 not 1.4) extender which will work with any lens - but the IQ is not great though they were only 50 quid brand new. I found cropping was better.
A far better (though more expensive) solution would be to get a used Canon 300 F4 L IS or a Canon 400 F5.6 L - pricey but very good!

 

[chrysoberyl]

Update: I returned the lens as it fit loosely on my Canon 6D. Before doing so, however, I purchased a Sigma 1.4X TC and am very pleased with the results. BTW, the TC fit snugly on my 6D, as does my Sigma 85mm f/1.4.

 

[mackguyver]

Have any of you compared the Sigma to the Canon 180L? I'm curious about how they compare (beyond the obvious spec differences).

 

[traingineer]

Have any of you compared the Sigma to the Canon 180L? I'm curious about how they compare (beyond the obvious spec differences).

Well the main difference is the Sigma apparently focuses faster than the Canon, it's got IS and I think it's IQ is slightly better.

 

[mackguyver]

Have any of you compared the Sigma to the Canon 180L? I'm curious about how they compare (beyond the obvious spec differences).

Well the main difference is the Sigma apparently focuses faster than the Canon, it's got IS and I think it's IQ is slightly better.

Thanks traingineer. I bought the Canon before the Sigma existed, but the idea of not being able to (easily) use my Canon TCs is a spoiler. I use them quite a bit with the Canon.

 

[traingineer]

Have any of you compared the Sigma to the Canon 180L? I'm curious about how they compare (beyond the obvious spec differences).

Well the main difference is the Sigma apparently focuses faster than the Canon, it's got IS and I think it's IQ is slightly better.

Thanks traingineer. I bought the Canon before the Sigma existed, but the idea of not being able to (easily) use my Canon TCs is a spoiler. I use them quite a bit with the Canon.

Your welcome.

 

[chrysoberyl]

Update: I modified the Canon 2X III TC and it fits well now on the Sigma 180mm macro. My general impression is that my shots are sharper with the Canon 2X III TC than the Sigma 1.4X TC.

 

[tculotta]

Mr. Mackguyver,

I have had the Sigma 180 f/2.8 macro for less than a week and can state unequivocally that I LOVE it. For sharpness, I think it beats my Canon L 100 f/2.8 macro and I love that lens a lot, too.

 

[mackguyver]

Mr. Mackguyver,

I have had the Sigma 180 f/2.8 macro for less than a week and can state unequivocally that I LOVE it. For sharpness, I think it beats my Canon L 100 f/2.8 macro and I love that lens a lot, too.

Thanks for letting me know. I really like my Canon 180 macro, but wish it had better bokeh (when stopped down it gets very octagonal). My copy seems really sharp, too, but the Sigma is a much newer lens and seems to do better in the tests I've seen.