View Full Version : Canon 1.4x III teleconverter with 400mm f5.6 L

Atul Sinai
29-08-2012, 09:24 PM
Tested Canon 1.4x III teleconverter with 400mm f5.6 L. works well, no auto focus, image quality is satisfactory.
Should be good for someone who is comfortable with manual focus.
Full frame image with camera setting- http://www.indiawilds.com/forums/showthread.php?t=10643
Below is the 100% crop

Keerthy Rajagopal
30-08-2012, 07:24 PM
Nice test Atul, and thanks for sharing. I have a question about manual focussing. Do you use a split screen focussing screen or just the original one?

Atul Sinai
30-08-2012, 09:04 PM
Hey Keerthy, I do not use split screen focusing. Generally prefer to use LCD with 10x to fine tune the manual focus. That can be done only is you use a tripod and you get time with the subject.

Otherwise, try to get the best using the viewfinder. Good light definitely helps here. For the above image I used the viewfinder to manually focus, as Ashy Prinia keeps moving around pretty quickly.

Sabyasachi Patra
01-09-2012, 03:16 PM
I agree. Auto focus can only be done at f8 with a 1 series body (excluding 1D X) at the centre point AF. However, better to try manual focusing when required. While photographing handheld we move a lot. If you are manual focusing while shooting handheld then it will impact.

According to Canon, the 1.4xIII and the 2xIII Tcs are basically meant for the new telephoto lenses. With the previous generation lenses, it doesn't give any advantage over the version II Tcs.

Rajan Kanagasabai
09-09-2012, 08:38 AM
I have experimented on this subject by taping over three of the contacts on the teleconverter so the DSLR doesn’t know you’re using a teleconverter.

I have tried this on two combinations. The 40D with the 100-400 and a 1.4X TC and the other combo was a 400D with the 150-500 APO and a 2X TC.

Both had worked quite well on the very few occassions i had tried them on the field, but blogs and even the Canon site says this may be an unreliable workaround and can behave erratically.


Atul Sinai
12-09-2012, 07:03 PM
Hey Ranjan, tapping the pins has worked well for me as well.

I was able to get single point AF and 560mm at f5.6.

Auto focus is not consistent and quite slow when compared without extender. Auto focus here would require manual fine tuning on most occasions.

Sharing an image of Black Kite in flight using auto-focus with 1.4x III extender (tapped pins) and 400mm f5.6L

Canon 7D. 400mm f5.6 with 1.4x III extender (tapped pins)
Manual Exposure
Auto Focus
Manual metering
Shutter Speed 1/1000
Aperture 5.6
ISO 640
Focal Length 560mm
Full Frame

Sabyasachi Patra
12-09-2012, 10:49 PM
There are also Teleconverters like Kenko which are non-reporting. So your camera believes that it is still a f5.6 lens and does the auto-focus. You of course need to manually reduce the exposure taking into account the TC.

With the kind of resolutions the cameras have these days and the amount of cropping done to the images, if the focus is not spot on, then the image looks soft. So I would prefer manual focus in most of the cases rather than taping the pins etc. However, during handheld autofocus is always welcome with slight finetuning the focus manually by hand.