Rob, John Shaw in "Closeups in Nature" says to put the TC on the camera body, the tubes in front of it and the lens in front of that. This way you multiply your extension, thereby allowing you to focus closer and increase your magnification.
If you put the tubes on the body and the TC in front of the tube you are multiplying the lens focal length but the extension is the same. Therefore your magnification would be lower than using just the tubes. I've actually been experimenting with my 300/4 Sigma, Sigma 1.4x TC and Vivitar tubes. I'm trying to gain working distance over my 105mm lens at life-size. With the 300 I can get life size with about 2 feet or so of working distance compared to just inches with the 105. Of course the light lost due to extension and TC makes focusing hard, but so far my test exposures with flash have been pretty good. What I really need is a 200/4 FA* or A* macro lens..... Christian Skofteland [EMAIL PROTECTED] ----- Original Message ----- From: "Rob Studdert" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, January 13, 2004 3:15 AM Subject: TC and Tubes for macro > Has anyone performed tests on TC/tube combos for macro use? If you were using > tubes and a TC would you put the TC or tubes directly behind the lens? > > Cheers, > > Rob Studdert > HURSTVILLE AUSTRALIA > Tel +61-2-9554-4110 > UTC(GMT) +10 Hours > [EMAIL PROTECTED] > http://members.ozemail.com.au/~distudio/publications/ > Pentax user since 1986, PDMLer since 1998 >
