Hoi Marc, >> So if I use my cheapo >> Tamron teleconverter, the camera does not know about the smaller maximum >> aperture, ergo it will not use it's compensation table, regardless if I use >> the EOS 5 or an EOS 3 for example. So, does this mean that with a >> third-party teleconverter I ALWAYS have to apply the correct amount of >> exposure compensation manually???
> Hi Bart, I'm very curious about this as well, as I've just bought a (used) > Kenko Pro300 for my 30. If anyone has experience with this TC/combo, or other > general worthwhile tips&tricks on how to get the most out of a TC, it'll be > more than welcome :-) As far as I know there are two different types of teleconverters out there: the 'intelligent' ones that 'talk' to the camera and the 'dumb' ones that don't. You can tell them apart by checking out the number of electrical contacts on the camera-side of the TC. If you see the same amount of contacts on your TC as on the camera itself (about 10 or 11, if I'm not mistaken) you have an intelligent TC (I believe the Kenko Pro 300 is such an 'intelligent' TC. All Canon extenders are also 'intelligent'). If there are three contacts missing on your TC (which is the case with my Tamron MC7) it is a 'dumb' one. The intelligent TC reports the true aperture to the camera. This may be an advantage, since I suspect that the camera needs this information to make the correct exposure compensation. On the other hand, if the resulting maximum aperture becomes smaller than f/5.6 most EOS cameras (except for the EOS 3, which can AF down to f/8) will disable AF. With a 'dumb' TC the camera will not disable AF. However AF performance will be affected, and the camera will probably hunt a lot more or fail to lock focus at all, depending on the brightness of the scene and the contrast of your subject. It is possible to change an 'intelligent' TC into a 'dumb' one simply by putting a piece of tape on the three contacts that are used by the cmara and the TC to communicate (I don't know by heart which contacts these are, but I can have a look when I'm at home). This might also result in an interesting experiment: put your camera on a tripod in your home (or any other place where the lighting doesn't change suddenly). Attach your 'intelligent' TC and a lens to the camera and take a meter reading. Now change this TC into a 'dumb' one and meter again. If the readings differ, this must be due to the compensation applied by the camera. > Also Bart, are you planning to put the images of your trip on a website > somewhere? I am planning to make the same trip myself next year and it would > add to the pre-fun to see your results. Well, I would like to put some of the images on the net, but I have no experience with this. Does anyone have tips on how to do this without much hassle? Anyway, Marc, if you have questions or if you would like to know anything beforehand, feel free to contact me off-list. Groeten, Bart _____________________________________ CONFIDENTIALITY : This e-mail and any attachments are confidential and may be privileged. If you are not a named recipient, please notify the sender immediately and do not disclose the contents to another person, use it for any purpose or store or copy the information in any medium. * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
