Nuke products support multiple file formats, such as Cineon, TIFF, OpenEXR, HDRI, and RAW camera data (using the dcraw command-line program), and allows you to mix them all within the same composite. By default, Nuke products convert all imported sequences to their native 32-bit linear RGB colorspace. You can, however, use the Colorspace node to force one of several color models, including sRGB, Cineon, rec709, gamma 1.80/2.20, HSV, or HSL. The Log2Lin node lets you convert between logarithmic and linear colorspace (and vice versa).
NOTE: Nuke Assist does not support Colorspace or Log2Lin nodes. See Flavors of Nuke for more information.
There are no restrictions on image resolution - you can freely mix and scale elements of any resolution within the same script. You can, for example, use a 2k film plate as the background for video shot in PAL format, and then output the result in HD1080i. Nuke products automatically adjust their Viewers to accommodate the image you’re viewing.