April 12, 2017

Cineflat: A Nikon Flat Picture Control for Videography

A full guide on better DSLR video is coming soon on Photograph IO. Stay tuned.
Let’s face it : DSLR cameras (and mirrorless cameras now) are not only great tools for photography, but they can also be excellent rigs for video. With the advent of the Nikon D90 in 2008, being the first DSLR able to shoot HD video, more and more people have been starting to get into cinematography using interchangeable lens cameras. With their large sensors, DSLR’s allow you to get that cinematic, shallow depth of field while still retaining a great amount of control over the final result for quite an affordable price.
However, one major drawback of DSLR’s compared to dedicated motion cameras from Red, Arri or Blackmagic is in their mediocre, at best, output. While high end motion cameras costing tens of thousands of dollars can shoot in near-lossless, Apple Prores 442 or even RAW video, most DSLR’s are limited in their output quality by the highly compressed codecs used not to mention a lower bitrate. Some of these limitations are hardware based (i.e. overheating, processing power), while some others can be cured by software and firmware. Unless you have a D800 or 5D Mark III capable of clean HDMI output, chances are that your output video is compressed.
But there is a way of improving this. Canon cameras have historically (and still are to some extent) been better than Nikon at motion photography. Not only do they have higher bitrates, better firmware (full manual video) and hacks (Magic Lantern), but they also have professional, flat picture styles specifically made to maximize dynamic range in video (Technicolor’s Cinestyle).
What about Nikon owners?
Although you could manually dial down contrast and saturation in camera, one of the most popular Nikon flat picture controls out there for cine is Tassinflat mady by Ulysse Tassin. While shooting using a flat picture control will look flat and contrast-lacking straight out of camera, flat footage will actually retain a greater amount of detail and dynamic range when it comes down to editing and color grading later on, which is great. Another popular profile is Alvaro Yus.
But there is now another contender in flat cine profiles for Nikon DSLR’s : Cineflat.
What is Cineflat?
Cineflat is our own Nikon flat picture control made for cinematography. Just like any other custom flat profiles out there, our flat profile is based on the principle of a logarithmic curve to maximize dynamic range in-camera for better color grading. You then apply an S-curve and color grade your footage to restore a standard look in post-prodution. Also, there is no sharpening applied and saturation is set at 0 in order to minimize video compression artifacts.
Why use Cineflat?
To increase dynamic range in video files and faciliate color grading in post-production. Cineflat will allow video to have about 11-12 stops of dynamic range on Nikon DSLR’s, compared to 10 for Tessinflat, 9 for Nikon’s neutral and portrait profiles and 8 for Nikon’s standard, vivid and landscape profiles.
What is different about Cineflat (compared to other flat picture controls out there) ?
Photographio’s Cineflat Nikon picture profile is designed to maximize dynamic range at both the shadows and at the highlights. Theoretically speaking, a logarithmic curve of gamma 0.45 (2.2 inverse) should be enough to get a logarithmic (aka flat) transmission on any camera. However, no sensor has perfect light transmission and therefore a simple gamma curve is not enough. Also, there are other things to worry about when it comes to shooting compressed video, such as highlights clipping and shadow detail. Therefore unless you are shooting RAW video, modifying the standard gamma curve is necessary to get optimal results.


0.45 Gamma
This is a standard 0.45 (2.2 inverse) gamma curve needed to produce a logarithmic sensor response. However, notice how prone the highlights are to clipping, which is absolutely something to avoid in compressed video codecs.
Screen Shot 2014-08-23 at 3.42.23 PM
Tassinflat, although logarhitmic in the shadows, has a strong reverse curve in the highlights area to minimize clipping.
Screen Shot 2014-08-23 at 3.42.42 PM
Alvaro Yus is based on a 0.5 (2.0 inverse) gamma curve for better shadows but near-linear highlights, prone to clipping.
Our own Cineflat profile, based on a modded Tessinflat curve. Notice how the shadows are much more boosted in Cineflat.
Our own Cineflat profile, based on a modded Tessinflat curve. Notice how the shadows are much more boosted in Cineflat.
Cineflat
Cineflat
Tassinflat
Tassinflat
Nikon Standard
Nikon Standard
Cineflat
Cineflat
Tassinflat
Tassinflat
Nikon Standard
Nikon Standard

Don’t get us wrong; Tassinflat and all other profiles out there are still excellent flat, logarithmic picture controls. However, Tassinflat’s custom curve was specifically engineered to prevent highlight clipping, at the expense of dark shadows. Alvaro Yus, another flat cine profile, improved on Tassinflat’s shadows by focusing on shadow detail instead, at the expense of highlights. We thought, why not combine both?
Therefore we launched Nikon Picture Control Editor (an unofficial, online version) and modified Tassinflat’s curves (which is itself based on Nikon’s neutral profile) for a better shadow response while still maintaining the reverse curve in the highlight zone. Our goal here was to do a logarithmic curve while still preventing highlight clipping. Theoretically at least, compressing both the highlights and the shadows should yield the best results in terms of dynamic range. After measurement, we found out that Cineflat indeed brings up about 1 extra stop of dynamic range compared to Tessinflat.
We also made sure that there was no tonal overlap (e.g. shadows brighter than highlights, or that mushy HDR look) even with such a strong curve. Also, do note that our curve will tend to overexpose by 1/2 to 2/3’s of a stop. This allows shadows to be further boosted while slighly exposing to the right to maximize SNR (which is basically tech speak for minimizing noise), similar to the exposing to the right technique (ETTR) in stills photography.
That being said, there are some caveats on our Cineflat curve. First of all, a heavy amount of shadow pulling is especially prone to noise even when exposed to the right, so you might want to denoise the footage in post-production first.
Also, there is a strong argument that while dynamic range compression is vastly superior to whites/blacks clipping created by high-contrast curves, too much tonal compression might also means a slight loss of detail. Why? Because compression, remember, is applied to a whole picture or video, not just to highlights and shadows. Although midtones are much less compressed generally in both photography and videography, lumping too much data there isn’t the ideal solution either. The amount of data loss in the midtones is however, minimal. While the difference in low dynamic scenes was negligible, I was able to recover a lot more data with less noise from Cineflat’s flat picture control compared to Nikon’s default standard picture control when it came down to mid and high dynamic range scenes.
Comparison pictures
Here’s some comparison pictures between Cineflat, Tessinflat and Nikon’s standard picture control. All three pictures from each set were shot using the exact same exposure in manual mode. Click on them to go in Lightbox view. Also, a video comparison is on the way.
And here are some indoor shots; underexposing Cineflat and Tassinflat’s pictures to match Nikon’s standard profile will reduce a lot of the noise seen :
The bottom line
When it comes to DSLR footage, a flat look is a must to preserve the most detail possible. For Nikon users, there are a few options available under the form of picture controls : Tassinflat, Alvaro Yus and now Cineflat. Tassinflat has great highlights, Alvaro Yus great shadows, and Cineflat tries to make a compromise between the two at the cost of being the flattest profile of the three.
While in most of the cases you won’t notice any significant difference after color grading between Cineflat, Tassinflat or Alvaro Yus, our Cineflat profile will have a slight edge if you tend to shoot regularly in high dynamic range scenes (mainly outdoors). A 3D LUT file for Davinci Resolve designed for Cineflat is on the way, but as for now, a standard S-curve should do the trick to “deflatten” the output.
Download
https://www.dropbox.com/s/sb2bd3s8dvd4cqn/Photographio%27s%20Cineflat.zip?dl=0
Simply share this article, and there you go! No spam, we promise.
If you found Cineflat useful, please share it to other Nikon videographers out there who might need it too, and don’t forget to check Photograph IO regularly for more photo and video tips and techniques 🙂