Your infrared shutter release will not work with the D800. I purchased a SMDV RFN-4s to use on mine. I think I paid about 60 bucks for it online. Works well as a shutter release and works in all modes including MUP. It has multiple channels in case your are using it where others are using similar devices. This is only a wireless shutter release and does not allow you to make changes to aperture, shutter speeds or other settings.