If you own a Nikon DSLR, this is a good time to perform a firmware update, because Nikon has just released new firmware that contains distortion control data for most of its current and older generation DSLRs, including Nikon D4, D90, D600, D800, D800E, D3100, D3200, D5000, D5100, D5200, D7000 and D7100. The distortion control data is used to correct barrel and pincushion distortion exhibited by Nikkor lenses. Please keep in mind that this data is only useful for correcting JPEG images. Distortion control data is not applied to RAW images (only to JPEG previews stored in RAW images) and if you use external image editors such as Photoshop and Lightroom, they will completely disregard this data when the RAW file is imported.
Still, it is a good idea to run the latest and greatest firmware on your camera. Also, this distortion control firmware is not a full firmware update for most cameras – it adds lens profiles to the existing camera database (firmware “L”). Before you apply the above update, I highly recommend to update your camera firmware (firmware “A” and “B”) to the latest version first. I wrote a detailed article on how to update firmware on Nikon DSLRs a while ago.