Filters in Modern Cinematography
With digital cameras creating very clean, high quality images with 4k+ resolution and lens makers creating lenses with almost zero imperfections, it might seem odd to be using glass plates in front of the lens, full of tiny imperfections to ultimately degrade the image in various ways.
I’ve been doing some testing for an upcoming feature film I’m shooting and I’ve been looking for the right look, starting with building the right LUT to keep the look of the film unique and consistent from on-set monitoring to post production. I then looked at diffusion filters and what effect they have on the look and how they will work in combination with the LUT I have created.
I have short listed a few options and created a test to see how they compare to each other. I will then pick 2 options and do a further real world test scene with multiple shots and focal lengths to see which is best.
The filters I have chosen are:
Tiffen Black Pro Mist 1/8
Tiffen Black Pro Mist 1/2
TIffen Smoque 1
Schneider HD Classic Soft
I set up a frame with the different elements in that would show the effect of the filters. Including small specular lights, a larger soft bright source and skin tones, with good highlight and shadow areas.
The camera settings for the test are:
Zeiss Milvus 25mm @ f.1.4
2k Prores 4444
Key light: 5600K
Here are the stills of each filter, using the LUT designed for the film. Click for full size.
You can see how the Black pro mists add soft blooming or halo to the light sources and the Smoque gives a nice even larger blooming and lower contrast look but less of a halo effect on the fairy lights than the BPM filters. The Smoque is designed to give the look of a haze filled room without the complications of continuity issues of using haze machines on set. The last still is my two favourite filters stacked for double effect.
The HD Classic soft is an older filter designed for softening harsh HD cameras when most productions were switching from SD to HD. The filter does give very slight blooming to highlights but also reduces the overall resolution, so not ideal for large projection of the image and not the look I am going for on this shoot.
Interestingly the Black Pro Mist filters have the effect of lowering the exposure of the highlights giving the impression of extending the dynamic range of the image.
The obvious downside to using filters when filming is that the image cannot be changed if another look wanted in post, which is why testing is always advised before a shoot and why I opt for lower strength filters. I really Like the Smoque 1 and 1/8 BPM combination, this feels to me a great way of getting the classic lens look with new high quality glass, Although may be too strong for all situations and a combination of both, or singly will have to be used based on the scene or shot and the elements and light sources within that scene.
I have decided to do further tests with the Smoque, 1/8 BPM and a combination of the two.