Extension tubes explained

[Frankman]

Given the interest in this topic I thought I'd do a quick and dirty demo of the sort of magnifications that these can achieve. For this demo, I used the KM 18-70 3.5-5.6 lens. This is the budget kit lens. It's NOT a macro lens, so you should achieve similar results without much effort.

Fiirstly, the setup. Pretty self explanatory - see the picture. I tested all the shots at the same aperture f9, ISO 100 using wireless flash:



I took the next photo at the minimum focal distance for the kit length. THis is the highest "macro" magnification it's capable of (remember - this is NOT a macro lens):




I then took the same shot with a 12mm extension tube:



Next, with the 20mm extension tube:



Next, the 36mm extension tube:



Next, all 3 tubes stacked (total length 12+20+36=68mm):


I have not sharpened nor altered these shots in any way - straight from the camera, converted from RAW to jpg. If you want to get into macro, these are a good way to go. However, bear in mind that you will lose infinity focus. I've used these on several of my lenses, as well as my Sigma 105mm macro lens with good effect. Very versatile. Mine are Kenko brand, and have all the AF pins, so they're fully automatic.

HTH, Frank