Nikolai Sklobovsky
New member
Since I've been using taped pins on my Canon TCx1.4 (along with 100-400) a lot, Asher suggested I write a little how-to.
The problem with TC is that entry level DLSR (in Canon world - non-1D series) only autofocus with the lens as fast as f/5.6. Since TC effectively adds the the whole stop (and TCx2 adds two), the lenses like 100-400L f/4.0-5.6 simply won't autofocus. While this is not a problem for a fast glass (f/2.8.. f/4) or better cameras (aforementioned 1D series), us mere mortals have to find a workaround.
It's has been noticed that first three pins on TC are used only to communicate the extender info to the camera. Hence came the idea to put a piece of a very thing non-conductive material over them and thus effectively fool the camera into thinking it operates with the lens alone.
Caveats:
1) You need to dial 1EV exposure compensation (or count for that in full manual mode), otherwise your picture will be full 1 stop underexposed
2) It is NOT recommended to use lens in AF mode, since there will be A LOT of "focus hunting", thus causing a lot of wear and tear on the AF mechanism. Instead, switch the lens to MF mode and simply use focus confirmation.
3) TC presence/info will be missing from the EXIF (duh)
From my personal POV, the troubles with taping and hassles of exposure compensation are way paid off by keeping the ability to focus correctly.
As to the procedure - it's simple, fast and very forgiving. A bit akin to the wet sensor cleaning (but much cheaper, virtually free) - looks menacing at first, but after you did it once or twice, there is really nothing to it.
Original tutorial here.
Sample moonshot with taped-pins TC is here.
The problem with TC is that entry level DLSR (in Canon world - non-1D series) only autofocus with the lens as fast as f/5.6. Since TC effectively adds the the whole stop (and TCx2 adds two), the lenses like 100-400L f/4.0-5.6 simply won't autofocus. While this is not a problem for a fast glass (f/2.8.. f/4) or better cameras (aforementioned 1D series), us mere mortals have to find a workaround.
It's has been noticed that first three pins on TC are used only to communicate the extender info to the camera. Hence came the idea to put a piece of a very thing non-conductive material over them and thus effectively fool the camera into thinking it operates with the lens alone.
Caveats:
1) You need to dial 1EV exposure compensation (or count for that in full manual mode), otherwise your picture will be full 1 stop underexposed
2) It is NOT recommended to use lens in AF mode, since there will be A LOT of "focus hunting", thus causing a lot of wear and tear on the AF mechanism. Instead, switch the lens to MF mode and simply use focus confirmation.
3) TC presence/info will be missing from the EXIF (duh)
From my personal POV, the troubles with taping and hassles of exposure compensation are way paid off by keeping the ability to focus correctly.
As to the procedure - it's simple, fast and very forgiving. A bit akin to the wet sensor cleaning (but much cheaper, virtually free) - looks menacing at first, but after you did it once or twice, there is really nothing to it.
Original tutorial here.
Sample moonshot with taped-pins TC is here.
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