Learn how to adjust and lock perfect iPhone video exposure in FiLMiC Pro without upsetting tone mapping using the PolarPro Peter McKinnon Edition Variable ND Filters.
Apple has made it very difficult to take full control over an ever more powerful computational imaging pipeline. My experiences with the iPhone XS Max have taught me that it’s a battle I will never win. With the iPhone 11, Pro and Pro Max, Apple have significantly improved the stability, effectiveness and results of the AI camera system. I have learned that I get the best iPhone video exposure by locking down what I can and letting the AI do what it does best.
I want to share with you a surefire method to achieve an excellent iPhone video exposure while maintaining a low shutter speed, without upsetting Apple’s tone mapping algorithm.
The Best iPhone Video Exposure Method
In the past I would use a fixed ND filter to reduce the light entering the camera lens enough to target approximately a 1/48th second shutter speed. Then I rely on further small adjustments of shutter speed and/or ISO to achieve the final exposure.
Instead, I now dial in exactly the right density of ND using a variable ND filter to achieve a 1/48th second shutter speed at the lowest ISO. Then, I use FiLMiC Pro’s exposure reticle to target, and automatically expose for the brightest part of the image. FiLMiC Pro decides the final ISO (keeping it as close to minimum as possible) and Apple’s AI sets up tone mapping accordingly. Finally, I make only very small trim adjustments to the variable ND filter afterwards to reduce any highlight clipping.
I am still shooting the X-Rite ColorChecker Passport Video chart so I have a reference to correct the image in post. However, the rest of the steps I use to set up exposure in camera have changed.
Watch the video for the full steps for great iPhone video exposure using FiLMiC Pro on the “AI” image processing iPhones (XS, XS Max, XR, 11, 11 Pro, 11 Pro Max) using a variable ND filter.
The PolarPro Peter McKinnon Edition Variable ND Filters
You can use any variable ND filter for this, but I really like using the PolarPro Peter McKinnon Edition Variable ND filters. These are very high quality variable ND filters designed for DSLR and mirrorless camera lenses, but they work beautifully for controlling iPhone video exposure using a suitable cage and some step up rings.
Instead of making one variable ND filter that covers a large range of density, PolarPro have split the range into two separate filters. This goes a long way to preventing excessive cross polarization effects. The fused quartz glass and coatings make these some of the best quality variable ND filters you can buy.
The filters are beautifully made and packaged, and come with both hard case and a soft pouch, as well as a protective rubber cap. The cap also acts as a grip, making it really easy to thread the filters on and off.
One of my favorite aspects of the PolarPro Peter McKinnon Edition Variable ND Filters are the precision stop markings around the outside edge, giving you a indication of just how many stops of light you are reducing your exposure by.
If you want to find out more about these excellent filters, I highly recommend you watch Gerald Undone’s video below. He compares the PolarPro Peter McKinnon Edition VND filters to a selection of other competing filters.
Setting up iPhone video exposure correctly is critical to recording quality images you can color correct, color grade and otherwise manipulate in post production. With Apple’s new AI image processing the old way of controlling exposure by changing shutter speed and ISO in FiLMiC Pro is no longer reliable. The solution is to use a variable ND filter.
Pretty much all of the reviews I’ve read consider the PolarPro filters to be a solid investment. They aren’t cheap, but if you take care of them, you only need to make this investment once. Of course you can share them with a mirrorless or DSLR camera also. Buy the right size to cover any other lenses you want to use them with, and then get some step up rings to use them on your phone cage.
These filters are now a core part of my iPhone video setup for the iPhone 11 Pro Max, and have replaced the use of the fixed ND filters I have. However, I am still using the fixed ND filters for my iPhone 7 Plus and iPhone SE.