12th May 2004, 01:08 PM
TC or Extension Tube ?? (HELP)
Need advise from CS members. I just cant decide whether I should go for TC or Tube. I dont shoot too much macro since I'm using film. I will love to have TC 2x or 1.4 Does TC have any impact on my macro lens? I'm aware there are elements on TC. Any recommendation for TC type and price?
My lens are TOkina 80-200, f2.8 and Tamron 90mm SP.
12th May 2004, 01:59 PM
Why do you need to have an estension tube when your already own a great Marco lens , ie. Tamron 90mm ????
Originally Posted by sdx4670r
12th May 2004, 04:36 PM
Maybe he/she wants to get greater magnification?
Anyway, do note that when you use an extension tube, you are going to loss infinity focus. A lens with an extension tube becomes a dedicated macro lens, you can't use it for general photo taking (unless you generally take things an inch or two away from your lens.)
The teleconvertor retains infinity focus, is more versatile generally, but you need to shell out for a good one to retain image quality. You also get double the working distance for a given magnification, and you can get double the magnification at your minimum focussing distance (if you are using a 1.4X). The Kenko Pro series seem to be quite good...
12th May 2004, 04:51 PM
Get both the 1.4x TC and a 25mm Ext Tube.... won't go wrong with this 2..
12th May 2004, 06:35 PM
Thanks for the input, just wondering with TC 1.4x + the Tube 25mm will I get about 2x magnification or more than that ??
12th May 2004, 06:56 PM
depends on the focal length of the lens you use it on and the order in which you stack them.
90mm Micro (at 1:1) + 25mm tube = 1.27X (25/90+1)
90mm Micro (at 1:1) + 1.4X convertor = 1.4X
90mm Micro (at 1:1) + 25mm + 1.4X convertor = 1.27X x 1.4X = 1.778X
90mm Micro (at 1:1) + 1.4X convertor + 25mm = (25/126+1.4) = 1.59X
As you can see, you will NOT be getting more than roughly 1.8X
The maths is very rough and I would appreciate it if more knowledgeable people can check if its correct.