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It’s very popular now to shoot very dark, shadows are close to 0 and your highlights around under 40 IRE, it seems a difficult balance of maintaining detail in your shadows to not have too much noise and also being able to push them down in post and have the detail in shadows while you’re shooting.
I saw Greg Frasier shot a lot of The Batman sequences with ISO 320 to get clean shadows as it was a dark film overall, but also I see some DP’s shoot a lot of low light sequences in new shows and movies with the Venice 2 with its dual ISO of 3200.
I just wanted to see how people shoot darker either with shooting at a lower ISO to maintain shadow detail or use the dual ISO of more modern cameras?
I know this is a very complex conversation with using a LUT designed for shooting darker sequences and also knowing where your shadows can lie on different cameras, but does anyone have any info on how people do this?
Thank you!
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Hello,
It depends on the creative intent you’re trying to achieve.
In a photographic sense, noise is the difference in gradient from the mean signal.
Noise is inherent to any sampling of information. In the case of imaging, the electromagnetic activity of the sensor impacts all values it creates. Noise/interference from the reset line (shutter) and thermal noise, among many other causes, add differentiation in charge as the analogue signal is amplified and read out from the sensor.
It’s important to note there are multiple stages of analogue amplification; with an APS sensor, every photosite has an amplifier, and the base of every column of photosites (pixels) has an amplifier. Amplifiers increase the noise in ratio to the amplification of the signal. Noise is in direct proportion to the signal.
However, as this amplification is in the analogue domain, there are infinite steps. Therefore, the difference in gradient can be considered pleasing, incredibly, if not too overwhelming.
The final sensitivity after amplification in this analogue realm is considered a camera’s native ISO’ for dual native base cameras, which means your cameras have two readouts with different levels of analogue amplification.
The FX6 uses gain adaptive column amplifiers with a high or low gain option on the same line. The downside is that it reduces its dynamic range at its higher base.
Once your signal is quantized – I.E. sampled digitally in a radiometrically linear fashion. This is when you enter the realm of digital gain. Digital gain has a far more digitally disruptive effect.
By this, imagine you have an 18% grey card, and your camera is representing this card digitally, with a mean signal of R 18, G 18, and B 18. Now, let’s say, due to the impacts of sensor architecture, there are pixels representing a value of R 21 G 19 B 15; if one then amplified the quantized digital signal linearly, your mean signal would have an RGB triplet of R 36 G36, B36 and your astray pixel would have a reading of R 42 G 38 B 30, the linear difference has doubled because your signal has doubled! SNR is a ratio!
However, if you halved your signal (reduced your ISO by a stop), you would have R9, G9, and B9, and your astray pixel would have a value of R10, R9, and B7 values. You were reducing your noise by half.
There you go, that’s noise, that’s it, nothing else to it.
It’s lost information; the noise floor is where a camera can’t distinguish further information. If you raise the crap out of digital ISO, like Bradford Young, you lose details in the shadows, which could be artistically pleasant!
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Gabriel Devereux - EngineerThere’s no right or wrong answer here. Some people want a clean image and will try to work at lower ISOs, others either want some noise or have to work in low light level conditions and will use a high ISO.
I understand, I was inspired by a lot of David Fincher’s films and his new film, The Killer embracing a more modern clean look. I saw Eric Messerschmidt used ISO 320-400 on the V-Raptor for a cleaner look of course you need more lights for this, but I think it’s interesting how some people will shoot 1600 on the Mini LF for more grain in the image and some will shoot 400 for a cleaner shadow look.
A lot of people want to emulate film and have more noise or add grain in the image, but it’s interesting how Fincher has embraced the modern digital sensors and delved into this modern, sleek, clean look in his films.
Even with shooting at a lower ISO do you find yourself still overexposing the shadows by a half stop etc. just to have room to bring them down later?
Appreciate the insight!
Personally if I want it really dark but rather clean I go down to ISO 200, especially when shooting with cameras that have unaesthetic noise, to have some room to crush it in post.
If you want a texture shadow look then you really need to protect that area when you expose.
You can lower the ISO to move the dynamic range into the shadows. You can create a LUT that brings the image down a stop or two, and over expose the image slightly to get more detail in the blacks.
You could also go the other way and create a denser darkness by compressing the shadows. All depends on the type of “dark” you are trying to create.
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