In his latest video, The Math Photographer ran a detailed sensor comparison between four premium compact cameras: the Sony RX1R III , the Leica Q3 28 mm , the Leica Q3 43 mm , and the Fujifilm GFX100 RF .

Using a precise laboratory workflow, he tested dynamic range, noise, high-ISO behavior, and exposure recovery . All shots were captured remotely through the Sony Creators App to avoid vibration, exported as JPEGs, and analyzed with a Python script measuring four metrics — Structural Similarity Index (SSI), Mean Squared Error (MSE), Peak Signal-to-Noise Ratio (PSNR), and Average Pixel Value (APV).

Results by category:

Underexposure ranking:

• 1. Leica Q3 28 mm
• 2. Sony RX1R III
• 3. Fujifilm GFX100 RF
• 4. Leica Q3 43 mm

Overexposure ranking:

• 1. Sony RX1R III
• 2. Leica Q3 43 mm
• 3. Fujifilm GFX100 RF
• 4. Leica Q3 28 mm

High ISO ranking:

• 1. Leica Q3 28 mm
• 2. Sony RX1R III
• 3. Leica Q3 43 mm
• 4. Fujifilm GFX100 RF

Conclusion: Despite being the smallest and least expensive of the group, the Sony RX1R III delivered outstanding sensor performance — often ranking second overall and first for overexposure recovery. The Leica Q3 28 mm remains a benchmark for shadow and high-ISO recovery, while the Fujifilm GFX100 RF surprisingly placed last in several categories.

The Math Photographer concludes that sensor differences among modern cameras are now marginal in real-world photography — factors like workflow, ergonomics, and brand preference matter far more. Still, the Sony RX1R III earns special praise as “a proud winner despite its size.”