Diopters and Teleconverters

I've been researching on how to increase magnification in macro and came across 2 methods: diopters and teleconverters.

From what I understand, diopters reduce the minimum focal distance of the lens, while a teleconverter multiplies the focal length of the lens. My questions is that if the focal length is multiplied, would the minimum focal distance change (ie lengthen). If so, in order to achieve greater the 1:1 magnification, I would need to use both a TC and a diopter?

Thanks in advance.

I am no expert on this. I have the same set-up you look to be getting and use the Backscatter Macromate: http://www.backscatter.com/hostedstore/products/JS-MM-SLR.html The advantage is it is a wetlens and can be flipped down. Others use a Woody's diopter, here is a link to a thread on it:
http://wetpixel.com/forums/index.php?showtopic=10235

MJH may have a solution for you in those links. To answer your question--no, the minimum focusing distance does not change with a teleconverter. In effect then, a teleconverter does serve to increase your ability to get a bigger image at the same minimum focusing distance you now have. However (gotta be one of those tossed in), you lose light. If it is a 2x teleconverter you lose 2 stops. With diopters you don't lose any light. Even with the extra firepower of those Inons I'm not so sure you want the teleconverter, since diopters can get you to 1:1 reproduction. Giving up 2 stops underwater (or above water) can be a significant light loss.

I have a good friend that has mastered the 105mm w/ 2X teleconverter. He easily lights his subject up with dual Inon Z220's. What is the toughest is first finding your subject and secondly is a VERY thin DOF. I tried mine a few weeks ago in Bonaire and didn't get anything great....due to alot of surge. here is one of his pics:



You just need to have your strobes almost touching the end of your port.

Dave

I'm not sure "easily" is the word I would use But when it works, it works!

A dioptre is more user friendly and will allow you a greater variety of suitable subjects. A TC is going to be for those specialised dives.

I have the Close-up kit on my old Nikonos V. It consists of a diopter that fits over the normal camera lens and a framer that depicts the coverage and focal length. It was a pretty nice set up and didn't require extreme close up lighting to capture good shots. DOF was reasonable.

I also have the "tubes" and framers that push the focus to about 2 - 3 " in front of the lens. DOF is critical and the dome of my strobe was generally about 3" or so from the object being photographed. The tubes eat up the available light so you really need to flood your subject ...especially with the lower ISO levels.

'Slogger