Nikon WT-4A avenger 5 R LM WR is

5 R LM WR is a very compact semi-wide prime lens for the Fuji GFX series of large-sensor digital cameras

and a constant f4 maximum aperture

So if you're looking for a toy

The Foto Care 2x teleconverter doubles the focal length of an attached lens

36x magnifying eyepiece for select Canon cameras

Nikon WT-4A avenger 5 R LM WR isThe Nikon WT 4A is a wireless interface for Nikon D3, D4, D300, D700, D800, and, D7000 cameras. With Nikons Camera Control 2 software (not included) you can connect your camera to a PC for remote shooting via either WiFi or Ethernet. As you can see from the image, this is not a tiny device, and its mode of operation is definitely less casual than modern wireless systems, so you may want to look into what it takes to get this thing to do what you want.