Shredded debit cardDurham, England - December 7, 2011: A Visa debit card provided by HSBC (Hong-Kong Shangai Bank of China) in England is being cut (destroyed) with scissors after its expiration date. Number and signature are not fully identifiable.

The first instinct when buying extension tubes is “the longer, the better” because a longer extensions allows a bigger magnification.

However, not all images require large magnification.

I shot these two photos with two Nikkors, the 20/3.5 UD AI and the 50/1.2 AI-S on a Sony NEX-5.

The theory says that if I extend a 20mm focal-length lens with a 20mm tube, I can obtain a reproduction ratio of 1:1. In order to achieve this, though, a 20mm designed for reflex cameras, that is with a retrofocus optical scheme, would need to have the subject too close: actually, inside the lens itself.

I used a Nikon PK-11A that provides an extension of just 8mm. This allowed a dramatic perspective when mounted on the 20mm, and a moderate close-up (my hand rather than my fingernail!) with the 50mm.

The images are on sale on iStock.