Kenko teleconverter

tanjk · 18th November 2002

Hi,

I'm thinking of buying the Kenko 1.4 (or 2X) teleconverter. Before I do that, will appreciate if somebody can tell me if ...

1) The effective aperture will be communicated to the body. The body in question is the Canon EOS33.

2) If it does, will it lose AF if it is more than f/5.6? Or does it hunt like there's no tomorrow?

3) Do I need to compensate for the light loss?

4) Does it work with any lenses? (As opposed to the Canon ones only working with selected L lenses)

5) Does anybody has any sample pics taken with it? Best if the TC is slapped onto some consumer style zooms which is what I have in mind.

Many thanks....

Regards,
JK

ziploc · 19th November 2002

I presume you are asking about the Kenko Pro 300. If you don't mind hearing them from a Nikon user, here they are:

1) Effective aperture is communicated to the body for Nikon mount, and I expect this is true for Canon mount also. That is, when using 1.4x TC (1 stop drop), the camera will show f/4 when the lens is at f/2.8. Same for 2x TC except it drops 2 stops.

2) On my F90/F5 when it is slightly beyond f/5.6 (betwen f/5.6 and f/7 ?), it will hunt a bit under poor lighting/contrast but is acceptable under bright sunlight. Will not AF when you get way over f/5.6. Not sure about Canon.

3) No compensation is needed. The TC will convert the f value according to the effective aperture and communicate it to the body.

4) For Nikon, it works with *all* lenses in both AF and metering. Canon I'm not too sure, need to ask the Canonians here.

5) Ask the Canonians.

Hope that helps.

Simon · 19th November 2002

Yap, it work with all Canon Lens.

Then again, anything above the f/stop of f/8, the auto focus will keep hunting and not work.

Example: your lens at 400mm is @ f/5.6 and you add a 2X TC which make your Effective aperture +2 Stop to 800mm @ f/11

There's a way to trick the camera fooling it to belive your Effective aperture is still @ f/8 and get the Auto Focus to work, but, that's another story.

It should be the same with Nikon or any other brands.

tanjk · 19th November 2002

Sorry if I wasn't too specific about the model, it's the kenko pro 300.

Okie, now assuming I'm at f/5.6 and I slap on a 2X TC, the effective will be f/11. So that means even if I set the physical aperture at f/5.6, the camera will still meter as if it's at f/11? Actually, this's the part that I need to clarify. If no AF then MF loh, no big deal since I don't intend to do sports with that combo. The other concern I have is I'm not sure if the view finder will be bright enough for accurate MF or not

The EOS33 is rather dim to start with ....

Anyway, the candidate I have for the combo are all the consumer class x-300. Any first hand experience on how bad the result will be? And thanks for the feedback.

Regards,
JK

hyun · 19th November 2002

simon teach us the "trick

" leh ...

18th November 2002	#1
tanjk Member Join Date: Mar 2002 Posts: 279	Kenko teleconverter Hi, I'm thinking of buying the Kenko 1.4 (or 2X) teleconverter. Before I do that, will appreciate if somebody can tell me if ... 1) The effective aperture will be communicated to the body. The body in question is the Canon EOS33. 2) If it does, will it lose AF if it is more than f/5.6? Or does it hunt like there's no tomorrow? 3) Do I need to compensate for the light loss? 4) Does it work with any lenses? (As opposed to the Canon ones only working with selected L lenses) 5) Does anybody has any sample pics taken with it? Best if the TC is slapped onto some consumer style zooms which is what I have in mind. Many thanks.... Regards, JK

19th November 2002	#2
ziploc Moderator Join Date: Jan 2002 Location: Snoopyland Posts: 3,180	I presume you are asking about the Kenko Pro 300. If you don't mind hearing them from a Nikon user, here they are: 1) Effective aperture is communicated to the body for Nikon mount, and I expect this is true for Canon mount also. That is, when using 1.4x TC (1 stop drop), the camera will show f/4 when the lens is at f/2.8. Same for 2x TC except it drops 2 stops. 2) On my F90/F5 when it is slightly beyond f/5.6 (betwen f/5.6 and f/7 ?), it will hunt a bit under poor lighting/contrast but is acceptable under bright sunlight. Will not AF when you get way over f/5.6. Not sure about Canon. 3) No compensation is needed. The TC will convert the f value according to the effective aperture and communicate it to the body. 4) For Nikon, it works with all lenses in both AF and metering. Canon I'm not too sure, need to ask the Canonians here. 5) Ask the Canonians. Hope that helps.

19th November 2002	#3
Simon ClubSNAP Admin Join Date: Jan 2002 Location: ClubSNAP Town Posts: 1,791	Yap, it work with all Canon Lens. Then again, anything above the f/stop of f/8, the auto focus will keep hunting and not work. Example: your lens at 400mm is @ f/5.6 and you add a 2X TC which make your Effective aperture +2 Stop to 800mm @ f/11 There's a way to trick the camera fooling it to belive your Effective aperture is still @ f/8 and get the Auto Focus to work, but, that's another story. It should be the same with Nikon or any other brands.

19th November 2002	#5
hyun Member Join Date: Nov 2002 Location: Farrer Road Posts: 394	simon teach us the "trick " leh ...