Kenko pro300 2x and Sigma 70-200mm

[Haro]

Hi, Need your expert advise on the compatibility issue(if any). I remember that I have read it in this forum before but just couldn't locate the thread.

My D70 couldn't auto focus when tc and 70-200 /f2.8 attached. Is this a known problem or I need to set some special setting? Pls share your experience.

Rgds.:embrass:

 

[Dennis]

I have the Kenko 1.4x and there is no problem, only aperture readout is not correct but other than that it is OK. 2x should be the same. F2.8 X 2 = F5.6 which should allow focus other than the occasional hunting. I have even stack 1.4x plus Nikon 2x on the 70-200 and on bright day can still autofocus.
You may want to check on your TC.

Hi, Need your expert advise on the compatibility issue(if any). I remember that I have read it in this forum before but just couldn't locate the thread.

My D70 couldn't auto focus when tc and 70-200 /f2.8 attached. Is this a known problem or I need to set some special setting? Pls share your experience.

Rgds.:embrass:

 

[Haro]

Thanks Dennis. I have tried my kenko tc on my Nikon 50mm, work fine. To my surprise, when use with my kit lens, the AF also works fine too. The f-stop is also showing correctly, 7.1-9.0. Can't explain.:dunno:

 

[clive]

sigma lens can only use sigma tc and not kenko pro tc. not sure if true or not. maybe u try with a sigma tc then it should be able to AF.

 

[Haro]

Thanks Clive. That is what I hate to hear most(not compatible). That mean I have to get rid of my kenko and get Sigma tc. :sweat:

 

[Dennis]

Sorry Haro, my mistake, I was testing it on the Nikon 70-200 f2.8 not the Sigma.

Thanks Clive. That is what I hate to hear most(not compatible). That mean I have to get rid of my kenko and get Sigma tc. :sweat:

 

[wilis128]

sigma lens can only use sigma tc and not kenko pro tc. not sure if true or not. maybe u try with a sigma tc then it should be able to AF.

from what i knw sigma 70-200 shld be compatible wth kenko pro tc.. in fact the kenko 1.4tc can be used wth sigma macro 105mm when even sigma's own 1.4tc cannot be used becos of its protruding element.

 

[Haro]

Dennis - It is ok. Good to have you chipping in some of your tries. Greatly appreciated.

Wilis128 - Thanks for your info too.

Anyone here has a success story on kenko pro tc with sigma 70-200? Anyway fyi, I have just wrote to both Sigma and Kenko abt this. At the moment, I will have my fingers crosses and hope that they will response.

 

[Denosha]

I just got my sigma 70-200 EX today from TCW. Anyway, the guy was telling me have to use the sigma TC otherwise ur AF will hunt.

 

[reflecx]

While researching on the 70-200, I remember reading that Sigma HSM lenses are not compatible with other teleconverters. Non-HSM Sigma lenses like the 105mm should be fine.

 

[amateur_photographer]

Thanks Clive. That is what I hate to hear most(not compatible). That mean I have to get rid of my kenko and get Sigma tc. :sweat:

no worries. you can always sell to me

 

[Haro]

no worries. you can always sell to me

Not a bad idea. :think:

reflecx, Denosha - Thanks for the info.


Below is the reply from Kenko - Just to share it with you guys.

Unfortunately, we have never tested Kenko converters on anything other than prime lenses (Nikon, Canon, Minolta and Pentax). So it is possible that the converters will not function in AF mode. :dunno:

Glenn Nash
Technical Service Representative
THK Photo Products

 

[Haro]

Here is the reply from Sigma Corp. :cry:

Thank you for your inquiry. We are not familiar with the Kenko teleconverters, therefore we cannot assure that they will be compatible with the Sigma lens. The 70-200mm lens is HSM type similar to Nikon AF-S type lens. There is no mechanical AF coupling because the lens has a built-in HSM motor for AF function. The teleconverter may not compatible with this function. Try contacting Kenko (THK) for information, they are a reputable company. Otherwise, the Sigma EX teleconverters will be compatible with your Sigma lens. We hope this information is helpful to you.

Sincerely
SCA-