In the world of digital cinematography, the choice of ISO settings can significantly impact the quality of your footage. Many filmmakers rely on the manufacturer’s recommendations, but is this approach always optimal?
Native ISO: Is 800 Really What You Should Be Filming At?
In today’s era of digital cinematography, many filmmakers default to the recommended ISO settings provided by their camera’s manufacturer. But is this always the best starting point?
I would argue that it depends on what you are filming and, more importantly, the type of image you are trying to create.
The International Organization for Standardization (ISO) sets the standards for camera sensitivity, which filmmakers often rely on. The recommended ISO for most digital cinema cameras is 800, which typically yields the cleanest images with the highest dynamic range. Consequently, this setting is frequently used by filmmakers who seek to capture the cleanest image with the most information without sacrificing dynamic range.
However, this isn’t always the case.
The Latitude Shifting Technique
Take the Arri Alexa, for example, which has a defined number of stops of dynamic range. With the ISO set at 800 and 14 stops of dynamic range, you gain 7 stops of latitude in the highlights and 7 in the shadows. This is how we achieve those crisp, clean images familiar in modern digital media.
Historically, before the digital age, film often struggled to capture details in shadows while retaining highlight information in bright environments. Many cinematographers prefer the rich, realistic look that film provides (myself included!). Therefore, adhering strictly to native ISO settings may not allow you to achieve a film-like aesthetic. To do so, you may need to employ a technique called “latitude shifting,” which involves deviating from native ISO settings. This opens up new avenues for capturing images.
With many high-end digital cinema cameras (like the Arri Alexa LF), increasing the ISO allows you to gain latitude in highlights while sacrificing it in shadows. Doubling the ISO effectively doubles the light, providing one additional stop of latitude in highlights while reducing one stop in shadows.
This results in 8 stops of dynamic range in highlights and 6 in shadows. Doubling it again gives you 9 stops in highlights and 5 in shadows. This technique is commonly utilized in very bright environments (deserts, snow, sunny days, etc.) where shadow detail is minimal, yet highlight information is abundant. It protects your sensor from clipping and blowing out highlights with little loss in shadow detail.
But what happens if you apply this in a “normal” scene?
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How to Create a More Filmic Look With Digital
In less illuminated scenes, many cinematographers might revert to the native ISO or even lower. However, I argue that this is where we might miss out on creating something magical.
I have found that maintaining a 1600 ISO (and sometimes pushing to 2000 or even 3200) in darker environments yields a more filmic image. Essentially, we are encouraging a digital cinema camera to behave similarly to motion picture film emulsions, capturing more highlight information while allowing shadows to clip a bit sooner.
Dealing With the Noise Problem
Of course, shooting at higher ISOs introduces digital noise, which some may find undesirable. Personally, I believe that a bit of digital noise can be acceptable, but this is subjective. Additionally, many software programs, such as Black Magic DaVinci Resolve, offer excellent noise reduction tools if you wish to minimize digital noise.
A simple method to clean up an image while preserving that film look is to eliminate Chroma noise (the colorful speckles in your digital image) while leaving Luma noise intact. Luma grain resembles film grain, maintaining an organic feel to the image.
A more advanced approach involves using custom-built subtractive LUTs. This technique allows you to shoot a much brighter image while viewing a darker one, retaining all sensor information and pushing the introduced noise into the shadows, making it less distracting.
Conclusion
In filmmaking, we continuously learn new ways to craft images. If you’re aiming to make your digital footage appear more filmic, I encourage you to experiment with higher ISOs. It’s always beneficial to try new techniques and discover what resonates with you. Find your unique voice and create the art you wish to see!
