The iPhone randomly takes 12MP and sometimes 24MP photos from the x1 camera even though it defaults to 24MP. Night mode is not activated. Does anyone know how to solve this?

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This may help --> Photography using iPhone - Apple Community

• Check Formats: Newer iPhones like the 13 Pro and 14 Pro offer format options in the Camera settings. Go to Settings > Camera > Formats. Ensure "Photo Capture" is set to "High Efficiency" or "HEIF Max" for 24MP photos. If "Most Compatible" is selected, it might default to 12MP for wider compatibility.
• ProRAW: If you have "ProRAW" enabled, it captures high-resolution images but at a lower resolution depending on the chosen setting. Check the "ProRAW & Resolution Control" option and choose "HEIF Max" or "ProRAW Max" for full 24MP resolution.