Canon 1.4x II Extender Tap Trick?

[raylks]

Anybody heard of tap trick on Canon 1.4x II extender?
How to do it? And what result I shall expect from doing so?

Thanks.

[CyberDyneSystems]

Tape?

Take the body cover off of your T-con.. (the side that attaches to the lens.)

You will see eleven little electrical contact pins in a row.
With the T-con facing you.. and the pins in s row at the TOP (12:00) of the T-con.. the three pins you tape are the three left most pins.

Just use a bit of scotch tape to cover them.
This MIGHT make your camera and lens combo continue to AF even if it did not beofre.
There are no guarantees,..

WARNING
If when you try it your lens behaves strangley,. if it "hunts" or AF is erratic.. REMOVE the tape!

Worst case scenario is you burn out your focus motor.

[robertwgross]

Part of the difficulty with this is that one piece of adhesive tape will transfer some of the adhesive to the gold contacts on the teleconverter. Then, if you remove the tape, some of that adhesive will be between the teleconverter contacts and the mating contacts inside the camera body. THEN, you have an intermittent problem.

You can minimize that problem by applying two pieces of tape, sticky sides together. The longer piece has its sticky ends to stick to the non-contact part of the teleconverter, and the shorter piece faces that to cover the contacts.

---Bob Gross---

[pierrot]

:shock: What are you talking about? Never heard of that. Tell us more! ;)

[lomond]

I tried the tape trick on my 75-300 as an experiment. It did work, kind of, but the AF does hunt and I was sometimes quicker with the manual focus.

Canon didn't pick a max of f5.6 for AF on the 10D, 20D etc for no reason.
Try it if you like but be warned burn out of the USM motor is a possibility.
I wouldn't dream of it on my 100-400L.

It's you're choice but be aware of the pit falls, doing this does invalidate you're warranty

[Cadwell]

Yup. I tried this as an experiment with the Canon EF 70-200L f/4, the Canon EF 2x Extender II and my 10D. Focus was erratic in all but the brightest light. Not recommended.

[Heffo]

Whats the point of the Tap Trick, what are you to gain from it???

[lomond]

AF for a lens plus TC with a minimum combined aperture of f5.6
i.e. the 100-400L would not normally AF with a TC.

[Bruce Watson]

If you want to try it, here is a link with a photo:

http://www.fredmiranda.com/TipsPage/

I think the earlier posts describe things accurately. I tried it with my Sigma 80-400 and 1.4.

It worked, but not reliably and to be honest, it was probably faster and more accurate to manually focus.

[Huckaback Photo]

Think the tape trick is far to fiddly in the first place !! Try it if you must at your own expense but then forget it as quick as possible.
( i'm sure canon would not have put all these nice gold plated contacts there to be covered up with tape and glue, if you still feel the need to do this properly take out your grinder or even a file and remove these extra contacts making sure to save any bits of gold !!!! TO USE AS DEPOSIT FOR REPLACEMENT NEW LENS )
totally agree with Cameron and Cadwell above focus is not good, better off to use manual as stated above.
Seriously... I think the 1.4 canon EF extender to be a good bit of kit in the right circumstances.
my favorite lens to use with 1.4 is the 200mm f2.8L. both my 1D mk 2 and D60 give variety of focal lengths when you work out the effective crop factors ( 1D =1.3x and D60 =1.6x) O k. we lose one f stop with this extender . as Cadwell above says "in all but the brightest light" which is something we sometimes lack here in wales (dark grey clouds outside as i type this)
no excuse not to get this extender if you live somewhere , constant blue skies, warm temp,clear blue sea, etc. etc. I'm only jealous.
Cheers
Martin (Huckaback Photo)

[Huckaback Photo]

Bruce
Just seen your post, it was the Fredmiranda site i first found out about this trick.

[chris maddock]

Yup. I tried this as an experiment with the Canon EF 70-200L f/4, the Canon EF 2x Extender II and my 10D. Focus was erratic in all but the brightest light. Not recommended.

There are differences in the way different lenses work with the extenders. My 70-200/f4 wouldn't focus properly at all with a taped 1.4x (Mk1) extender on a D30 or a 10D, whilst the 100-400 worked perfectly with it. That tip was originally only aimed at 100-400 users so probably hadn't been tried with the 70-200/4.
The 70-200/4 was fine with the untaped extender, so I taped the back of the 100-400 - now both lenses work fine, both with and without the extender.

KRs
Chris

[Cadwell]

There are differences in the way different lenses work with the extenders. My 70-200/f4 wouldn't focus properly at all with a taped 1.4x (Mk1) extender on a D30 or a 10D, whilst the 100-400 worked perfectly with it. That tip was originally only aimed at 100-400 users so probably hadn't been tried with the 70-200/4.
The 70-200/4 was fine with the untaped extender, so I taped the back of the 100-400 - now both lenses work fine, both with and without the extender.

KRs
Chris

I am deeply curious as to why you needed to try the tape trick with a 70-200f/4 and a 1.4x extender? That combination is supposed to autofocus fine, in fact I know it does. :confused:

[chris maddock]

I am deeply curious as to why you needed to try the tape trick with a 70-200f/4 and a 1.4x extender? That combination is supposed to autofocus fine, in fact I know it does. :confused:

Simple. I had a taped extender (already used it with the 100-400) which I didn't want to mess around taking tape off and putting it on depending which lens I was going to use, so I tried it - briefly ;-)
Hence why my tape is now on the 100-400 and the extender is as built.

The 70-200/4 and (untaped) 1.4x does indeed work fine - in fact I can't see any significant difference in focussing speed compared to the lens without the extender, it's an excellent combination.

KRs
Chris

[robertwgross]

Whats the point of the Tap Trick, what are you to gain from it???

We better avoid this. It's kind of a sticky situation.

---Bob Gross---