What is noise?
Noise are the random speckles that are mainly visible in photos that are made in low light and with a high ISO value. The ISO value indicates the light sensitivity of the sensor and a high ISO gives more noise. If you shoot with the iPhone Camera app, the noise will be removed for you. When you photograph in RAW, you will have to reduce the noise yourself with a noise reduction app.
There are 2 types of noise
- Color noise are multicolored pixels and you see them mainly in shadows.
- Brightness noise are small grains. They look like grain in old photographs made with film and have different gray levels. I find brightness noise less disturbing.
The standard iPhone Camera app and noise reduction
The app automatically applies noise reduction and will always take photos with the lowest possible ISO speed The minimum ISO value is 25. In low light, the iPhone first lowers the shutter speed to an exposure-time with which you still can photograph hand-held and will only then increase the ISO value. The recent iPhone models have bright and stabilized lenses, so that you can take pictures in low light with low ISO values.
Reduce noise of RAW photos
An iPhone RAW photo file is unprocessed. To keep the noise level low, it is important that you photograph with a low ISO value. Before you edit the photo, you can reduce the noise with the camera and photo editing app Adobe Lightroom CC Mobile. Noise is more visible when you edit the photo.
Reduce noise with the camera app Lightroom CC Mobile
Adobe Lightroom CC Mobile is a free Camera app, which can take pictures in RAW or HDR-RAW. An important advantage of Lightroom CC Mobile over other Camera apps is the noise filter. The app applies the noise filter by default to all photos you create or import. You can use sliders to determine how much color noise and brightness noise you want to reduce.
Examples
The pictures below are made with an ISO value of 400 and I zoomed in as much as possible so that the noise is clearly visible.
“Noise Reduction” and “Color Noise Reduction” are set to 0 with the sliders. These settings become visible when you tap on “Detail” in Lightroom CC Mobile. The brightness noise and color noise are clearly visible. 
The result of the settings that are applied by default to all photos you create or import. “Noise Reduction” is set to 20 and “Color Noise Reduction” to 25. Especially the color noise is reduced.
“Noise Reduction” is set to 100 and “Color Noise Reduction” to 50. The noise is removed but the fine details are also less visible. Due to the reduction of color noise, the colors have become a bit dull.Reduse noise with iOS 13
(Update 2019/9/24) With the updated Photos app in iOS 13 you can edit RAW photos and remove noise with the new Noise Reduction function.
Open a RAW photo and tap Edit. Select Noise Reduction and then change the amount with the slider.
Conclusion
The iPhone Camera app automatically applies noise reduction. With the noise reduction app and camera app Adobe Lightroom CC Mobile App Store you can easily remove noise from your RAW photos. By experimenting with the settings you can find the right balance between noise reduction and loss of detail.
(Update 2019/9/24) Noise reduction in the Photos app of iOS 13 works well. I think it is best to stay between the values 30 and 50 for an optimal result.
Go to the overview with all iPhone photography blogs.
The enlargements are taken from the photo below.
Recommended for you
