What firmware should I use on an I1 using both an X3 and XT camera? Should I use the Inspire 1 or inspire 1 Pro firmware or does it matter?  

The firmware includes support for 1) the airframe system and 2) the camera system. So with two cameras, you need two firmware downloads.

Go to https://www.dji.com/inspire-1/info#downloads
and select the X3 camera and download  the firmware. Then select the XT camera and download that firmware. Whichever one you apply first will update aircraft and camera. The next firmware you install will see that the aircraft is already updated and will update only the camera...

Daroga Posted at 11-20 09:20
The firmware includes support for 1) the airframe system and 2) the camera system. So with two cameras, you need two firmware downloads.

Go to https://www.dji.com/inspire-1/info#downloads

Thanks, There's a firmware update for the XT that says it only updates the gimbal and camera and that has to be done with the XT connected. My question is when I run the firmware update with the X3 connected shout I use the Inspire 1 firmware or should I use the Inspire 1 Pro firmware. I had the pro firmware once before when I had an X5 on it but now it's back to just the I1 firmware, not Pro.

I believe the Firmwares are kinda saved within the drone cause mine is an I1 Pro and i can use my X3, Z3, and X5 all without switching anything but the cameras

Hello and good day rstekeur. Thank you for the inquiry today. If the drone model is the DJI Inspire 1 then you need to download the DJI Inspire 1 firmware. I will post a link where you can find the latest firmware for the DJI Inspire 1. All you need to do is to choose the camera that you are using to update the firmware. https://www.dji.com/inspire-1/in ... e_search#downloads. Thank you.

rstekeur Posted at 11-20 09:26
Thanks, There's a firmware update for the XT that says it only updates the gimbal and camera and that has to be done with the XT connected. My question is when I run the firmware update with the X3 connected shout I use the Inspire 1 firmware or should I use the Inspire 1 Pro firmware. I had the pro firmware once before when I had an X5 on it but now it's back to just the I1 firmware, not Pro.

You are correct about the XT firmware being camera ONLY! - XT Release Notes. So apply the X3 firmware first to update your airframe. As you state, you must attach the corresponding camera for the firmware package to update the camera components.  Note that the camera will work with your Inspire 1 by attaching it to the airframe as the Inspire 1 cameras are self-contained. The firmware updates provide bug fixes and sometimes new capabilities. To check if you want or need to update the airframe or camera, review the Release Notes that are published for each firmware revision. Here's the Inspire 1 with X3 Release Notes -> Aircraft & X3 Release Notes. Note that the current camera firmware version is  v01.10.01.40. You can check your version in the GO App under the ABOUT menu.