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Macro Magnifcation Query

Started 8 months ago | Discussions thread
John K Veteran Member • Posts: 9,870
You have to manual test every combination
1

BBbuilder467 wrote:

With the 100mm lens, you would get an increase in magnification proportionate to the length of the extension tube. Adding 30mm tubes would be 1.3x. Use 68mm tubes to get 1.68x. Start with the shortest tube and work your way up.

Macro lenses that have internal focusing (the barrel does not extend) lose focal length at their minimum focus point. As an example Canon's EF-S 60mm is a 37mm lens at 1x, so it only takes 37mm of extension to get to 2x. Canon's 100mm lenses are roughly 72mm at 1:1, so your 68mm of extension would get you to almost 2x.

For the OP: Photograph a metric ruler and divide the width of your sensor by the number of millimeters you see in the photo to get the magnification. Do that for every combo you want to use.

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