BetterPhoto Q&A
Category: New Questions

Photography Question 
Manish Issar
 

Extension Tubes Vs. Tele-Converters


What is the difference between an extension tube and a tele-converter lens? Which one is better in terms of output/money ratio? I have a Canon Rebel EOS K2 SLR and would like to go macro. What do you suggest? I want to take decent pictures of floral parts - like the stamens. What magnification would that be? I was looking at ebay, and there are several mm tubes 12, 25, 35, etc. I am really getting confused. Could someone help?
Thanks, Manish


To love this question, log in above
11/18/2004 1:38:00 PM

 
Bob Cammarata
BetterPhoto Member Since: 7/17/2003
cammphoto.com
  The main difference between teleconverters and extension tubes is that the 'tubes contain no glass elements and the teleconverters do.
Also, teleconverters will increase the focal length throughout the entire focusing range - from the minimum focusing distance all the way to infinity. The extension tubes can only be used for close-up work ... as their basic function is to decrease your close-focing ability.
As an example, let's say you're using a 100mm lens that can focus from 12" to infinity. With a 2X-teleconverter, you could still focus from 12" to infinity, but the image would be twice as large.
With the same lens, and extension tubes, you could focus to 10", 6", or closer, depending upon how many millimeters of 'tubes you place between your camera and lens. The image size would be magnified exponentially, but you would lose the ability to focus on a distant object.
As to which is better for shooting close-ups of flowers, I would go with the extension tubes. They can be used with any lens of the same mount, and will allow you to get super-close.
Ideally, a true "macro-lens" would be the best option, but extension tubes can be a cheaper alternative.
Whichever you choose, depth of field and light loss are inevitable. A tripod and a small aperture are recommended.


To love this comment, log in above
11/18/2004 3:34:27 PM

 
Scott Pedersen   For Macro you need the tubes. Try to buy them as a set. Generally its a set of three. You can put them on one at a time or just go for it and try all at once. You need to manual focus them and also it is necessary to move the camera back and forth to foucus. You focus at a wide apature and then adjust your ap down. as you do this well on my ME Super anyhow it gets darker in the viewfinder and you can no longer see your subject. Lighting and DOF are very important when doing Macro. I think some kind of constant light would work better than the flash as you could see what you are getting. Personally my attempts at using the flash have failed. But Macro is a lot of fun.


To love this comment, log in above
11/23/2004 4:39:18 AM

 
Michael McCullough   I've been using extension tubes for a few years now with at times great results,and do recommend them over a teleconverter,less glass ,sharper image,I do try many focal lengths from 50mm.-200mm.this is also a cheap way of producing pro results!!!!


To love this comment, log in above
11/23/2004 12:21:15 PM

 
Log in to respond or ask your own question.