How to Use Fuji's New Reala ACE Film Simulation on Fujifilm XT-4

How to Use Fuji's New Reala ACE Film Simulation on Fujifilm XT-4
Photo by Claudio Schwarz / Unsplash

The instructions in this post are inspired by the original guide on accessing Nostalgic Negative on X-Trans bodies, initially shared by yayatosorus on dpreview. This post aims to simplify the process, allowing you to start using the Reala ACE film simulation quickly and efficiently.

Reala Ace Simulation Taken on XT-4 body

Fujifilm and the Kaizen Concept

Fujifilm was once renowned for its "Kaizen" philosophy, continuously releasing firmware updates to enhance the user experience of its older cameras. However, this practice has waned recently, leaving many users longing for the latest features and film simulations available only on new camera models. Instead of giving in to the pressure of buying a new camera, let's explore how you can enjoy the new Reala ACE film simulation on your existing X-Trans camera.


These instructions are tailored for macOS users. Windows users can refer to the original guide and use this post as a reference to adapt the steps accordingly.

Step 0: Install Capture One Pro

Download and install Capture One Pro from the official website. You can also use the Fujifilm RAW Converter if you don't have the paid version of Capture One Pro.

Step 1: Locate the Film Curves Folder

Open Finder, go to the menu bar, select Finder -> Go -> Go to Folder, and paste the following path:

/Applications/Capture One

Alternatively, navigate to the application folder, find Capture One 22, right-click to "Show Package Contents," and go to the specified folder. Note that this path may differ for other versions of Capture One.

Step 2: Copy and Rename the Reala ACE Files

Download the pre-packaged Reala ACE film simulation files. The files you need to locate in the "Film Curves" folder include:

  • .fcrv files: Camera-specific
  • .P1X files: Sensor-specific

Identify and select the 9 .P1X files and the .fcrv file related to Reala ACE. To simplify this process, use the following Python script to automate copying and renaming these files.

Python Script to Copy and Rename Reala ACE Files

Here's a Python script that automates the copying and renaming process. The script selects the FujiGFX100II files for "REALA" (case-insensitive) and renames them based on your input.

import os
import shutil

def get_reala_files(folder_path):
    reala_files = []
    for file_name in os.listdir(folder_path):
        if "reala" in file_name.lower() and ("FujiGFX100II" in file_name):
    return reala_files

def copy_and_rename_files(folder_path, camera_name):
    reala_files = get_reala_files(folder_path)
    new_files = []
    for file_name in reala_files:
        new_file_name = file_name.replace("FujiGFX100II", camera_name)
        src_file = os.path.join(folder_path, file_name)
        dst_file = os.path.join(folder_path, new_file_name)
        shutil.copy2(src_file, dst_file)
    return new_files

def main():
    folder_path = input("Enter the path to the 'Film Curves' folder: ")
    if not os.path.exists(folder_path):
        print("The specified folder does not exist.")
    camera_name = input("Enter the camera name (e.g., FujiXT4): ")

    new_files = copy_and_rename_files(folder_path, camera_name)
    if new_files:
        print(f"The following files have been created in {folder_path}:")
        for file_name in new_files:
        print("No REALA files found for FujiGFX100II.")

if __name__ == "__main__":

How to Use the Script

Save the Script:
Save the script to a file, for example,

Run the Script:

  • Open a terminal or command prompt.
  • Navigate to the directory where you saved the script.
  • Run the script using python

Follow the Prompts:

  • Enter the path to the "Film Curves" folder.
  • Enter your camera name (e.g., FujiXT4).

Step 3: Apply the Film Simulation

Once you have copied and renamed the files, open Capture One Pro and import a RAW file taken by your camera. In the Base Characteristics panel, you should now see the option to apply the "Fujifilm Reala ACE" curve. Select it, and enjoy the new film simulation.

If everything goes alright - you should able to see the REALA ACE in the list of the simulations. Let me know if the script doesn't work.