Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.
Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
The subject has come up before. See this thread - http://www.birdforum.net/showthread.php?t=97941. The taped pins trick certainly does work, but for some people it is poor to useless when combined with f/5.6 lenses. Mine works pretty well with my 100-400 lens. Others are less fortunate.
I binned the album of AI Servo shots referenced in the original thread so I've re-uploaded all the shots. These are all with the 100-400 at 400mm and with the Kenko 1.4X T-Con - http://picasaweb.google.com/EezyTiger/40D10040014XTCon?authkey=wBSOgtYC-YI. They are full sequences and not cherry picked individual samples.
Well, before my lens (EF 400 F5.6L) died it also worked fine with a taped Kenko Pro 1.4x on the 40D but somehow the center af-point flawed so after reading a lot of posts about it from this forum I switched the focuspoint to either the left or right side af-point(s) and it was good to go from then on, worked like a charm :t:
Most peoples experience (and certainly mine) is that the taped tc does not work particularly well with the centre focus point but works fine with one of the outer points. I have had success with the centre point with birds that show a lot of contrast, black & white birds for instance. It also works fine for for subjects like buildings but for most bird shots it can struggle.
The Kenko 1.5X work very fine with center and peripherial point of the 40D and the difference in quality compared to the pro model are minimal. however, the central point work better with very good light or contrasty subject. With the Kenko pro (pin taped), I've got a high rating of focus searching.
I have found the AF unusable when my kenko 1.4x converter is fitted between my 40D and 100-400. I have however tried the kenko 1.5x converter and have experienced much better AF ability with the same camera lens combo. There has to be plenty of light or I still experience hunting.
Image quality is slightly down but I have even managed to catch a Peregrine in flight with it. See well cropped thumbnail.