Welcome to this quick-fire guide to understanding your camera’s crop factor and how it affects your photos. If you don’t have a lot of time right now, simply download the PDF version of this guide to read offline.
All digital cameras that don’t have a full-frame sensor are referred to as cropped sensors. It means they are smaller than a full-sized one. This difference in size will reflect a difference in your photographs.
The size of your camera’s sensor will change the focal length of any lens you use. For example, a 50mm lens will never be truly 50mm on a cropped sensor.
1.29x crop factor for APS-H Sensors (Canon)
1.52x crop factor for APS-C Sensors (Other Brands)
1.61x crop factor for APS-C Sensors (Canon)
2.0x crop factor for Micro 4/3rd Cameras
2.72x crop factor for Compact Cameras
To work out your crop factor and how it changes your focal length simply multiply
FOCAL LENGTH X FORM FACTOR
50mm (focal length) x 1.29 (crop factor) = 64.5mm (equivalent focal length to 35mm/full frame)
85mm (focal length) x 1.52 (crop factor) = 129.2mm (equivalent focal length to 35mm/full frame)
100mm (focal length) x 2.0 (crop factor) = 200mm (equivalent focal length to 35mm/full frame)
The same goes for zoom lenses. If you have a standard kit lens (18-55mm) on an entry level DSLR camera (APS-C sized sensor) the once crop factor is applied that lens will actually be giving you equivalent focal lengths of between 27.36-83.6mm lens