2x Converter

[ianmandy]

I want to get a 2x converter for my canon 400D I will be using a 70-300mm USM Lens. The canon is out of my price range but i want to keep the AF function. I have heard the Kenko keeps the AF, it seems to be my only option as it is a 1/3rd of the Canon 2x converter price. Has anyone used the kenko or other 3rd party converters that will keep the AF function.
Thanks
Ian

[Ollie]

Originally Posted by ianmandy

I want to get a 2x converter for my canon 400D I will be using a 70-300mm USM Lens. The canon is out of my price range but i want to keep the AF function. I have heard the Kenko keeps the AF, it seems to be my only option as it is a 1/3rd of the Canon 2x converter price. Has anyone used the kenko or other 3rd party converters that will keep the AF function.
Thanks
Ian

As far as I am aware the Kenko converter will only keep the AF if you tape the pins on the converter to fool the camera into thinking the converter isn't there.

I occasionally use a 1.4 Pro 300 Kenko converter with my 400D and a Canon 400mm prime lens, and have to tape the pins so would assume you would have to do the same with a 70-300mm lens. Not sure what sort of quality you would get with a 2x converter on the 70-300mm because if I am correct you will lose two stops of light with the 2x converter attached.
Roger

[ianmandy]

Thanks for the advice Ollie . I think your right i will loose light.

[eeyore]

Originally Posted by Ollie

As far as I am aware the Kenko converter will only keep the AF if you tape the pins on the converter to fool the camera into thinking the converter isn't there.

I occasionally use a 1.4 Pro 300 Kenko converter with my 400D and a Canon 400mm prime lens, and have to tape the pins so would assume you would have to do the same with a 70-300mm lens. Not sure what sort of quality you would get with a 2x converter on the 70-300mm because if I am correct you will lose two stops of light with the 2x converter attached.
Roger

thats true of the kenko pro , but the cheaper kenko standard (or the jessops own brand which i think is made in the same factory and is identical except for the branding) will keep the af without having the pins taped.

however if you put a 2xtc on a 300 f5.6 lens you will create essentially a 600 f11 and as the 400D requires a max apperture of f5.6 for its AF to function the af will be very sluggish and hunt a lot even if it functions at all which isnt certain.

you would be better with a 1.4tc which would create a 420 f8 - here the AF might work in bright light but will still struggle in low light conditions.

all things considered you might be better off saving up for a second hand sigma 135-400 f5.6 which can be had in good condition for circa a couple of hundred notes ( however make sure that it works on a DSLR as some of the older sigma lenses dont)

[llanon99]

I use a Jessops own brand on my Nikon, and it delivers perfectly acceptable results, so long as you have sufficient light, of course. Chromatic aberration is evident however.

and they are relatively very cheap, for those of us who need to eat as well as take photos

:-)

llanon99

[kshotton45]

I have a 2X TC . I'm not too impressed by it. Basically, you need a VERY SHARP lens to begin with. The lens needs to be sharper than the resolution of the sensor. Otherwise, you might just as well enlarge the picture with Photoshop.

Keith.