Bright f/2.8 aperture Smooth, silent focus motor Ultra-low Dispersion glass The Canon EF 40mm f/2.8 STM is a pancake lens aimed at newcomers to photography wanting a lightweight, portable wide angle option for shooting landscapes and urban cityscapes. Thanks to the f/2.8 aperture low-light images aren’t an issue, and the 30cm close focus distance makes shallow depth of field possible. The portable nature of the Canon EF 40mm f/2.8 STM, coupled with the new STM focus motor which aids movie recording thanks to the smooth autofocus, means the Canon EF 40mm f/2.8 STM is an excellent companion to the more lightweight Canon DSLRs, such as the EOS 100D, making it excellent for travelling.