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  #17  
Old 06-11-2009, 06:54 PM
dpastern (Dave Pastern)
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Join Date: Jan 2009
Location: Brisbane
Posts: 2,874
The 50mm + tubes takes some getting used to. There are 3 tube rings - 12mm, 20mm, 36mm. You can add one ring, or all of them. Depending on how many rings you add to the 50mm, your overall magnification amount will change. As an example, a rough way of working out magnification:

tubes focal length/main lens focal length

if you were to put all 68mm of tubes on the 50mm, you'd get:

68/50, roughly 1.4:1 or 1.4x magnification.

If you were to only use the 12mm, you'd only get around:

12/50, or 1:4 or quarter life size. The 36mm tube ring would give you around 3/4 life size.

You can use these tubes with a dedicated macro lens as well (that's defined as a lens that gives 1:1 magnification out of the box). A full set of Kenko tubes and a dedicated macro lens will give you around 2:1. Pretty handy imho.

The 50mm is handy for doing other things anyways, so it's not a bad investment, and it's not expensive. Think of it as a stepping stone. Buying a dedicated macro lens straight away will give you more flexibility (easier to change magnification, you don't have to take off/on tube rings etc), but it's a bigger investment.

The choice is really up to you!

Dave
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