Issues with flat 11 profile on my nikon D7100

S

Stelvium

Well-known member
Hallo,

i need your help for an issue i'm having during the filming of my interviews with my D7100. I'm filming with Flat11 profile to have better options in post but here comes the problem. I'm finding a lot of Noise on the footage. I'm lighting the talent with a led with a softbox but in the background or in the black shirts i'm seeing many horizontal lines of noise (i guess). I'm using the 35mm f1.8 lens that is the fastest prime aperture lens i have (filminng at ISO 320 f4.0 1/50th). Is there any suggestion you could give me to get rid of those horizontal noisy lines?
Thank you in advance for trying to help me out
 
The above is heavily compressed, but I can make out some of the lines and they are familiar to me (had them on BM cameras).

Here is the main and only answer: If you have horizontal lines in your footage, they are being produced by a bad sensor or a sensor that's not creating motion pictures correctly (like a LOG image or an image where its settings have been highly altered, e.g. Flaat_11).

You can have noise, but not lines.

And unfortunately you cannot do anything about it besides trying to crush them out of your motion pictures and working around them (are they always there?). Truly recommend testing a neutral picture control so you can compare the differences (if any).
 
You need to expose to the right (ETTR) with flat profiles to avoid excessive noise.

Do those shots really warrant using the Flaat 11 profile? Flaat 11 is intended to extend your camera's latitude for high contrast scenes, but from the cropped-in frame grabs, the scene doesn't look high contrast.

Ebrahim Saadawi had a really good post on getting the most out of DSLR video. Some of the recommendations are specific to Canon DSLRs, but many of the principles apply. Here are Ebrahim's recommendations:

You can produce pretty amazing results with a Canon DSLR. The way to get the absolute highest image quality from them is as follows in my years of tests:

-Expose highly without clipping, underexposong is the key to getting crappy Canon footage. Use ML waveform or Histogram.

-Don't shoot with a third party picture style, they all have a downfall like a weird rendition of a certain coloir, increased noise at certain channels, the only one that's 100% consistent is Technicolour's Cinestyle (as it was developed with Canon) and of course the trusted Neutral with contrast -4.

-If you find the footage to be too soft, add a single notch in the picture style menu it really does make a difference, just try it.

-Moire and aliasing are your only enemy in Canon DSLRs so avoiding wide detailed landscape shots and concentrating on longer close up coverage makes the quality appear to audience so much better.

-Take that footage into your editor natively, straight from the camera, edit cut and colour grade the footage to your liking (and work in 16/32bit space)

-After you reach the final result, add a layer of neat video, go to advanced tab and tweak the NR settings to your exact preference, adding NR before grading is much worse than after, as doing it after grading eliminates the colour pushing artefacts and gives an overal higher control of how NR will look.

-If the image is too soft, add a sharpening filter here after NR, a small one.

-If you have banding or find the footage too clean, dither by adding a small layer of grain.

-Export at ProRes or DNxHD.

Don't complicate it too much. Just edit natively, grade, NR, sharpen, dither or not, export to a high quality format (anything not lpwer than the native H.264 34mbps 4:2:0 8bit)
 
One thing i can tell you is thank to Neat Video the lines disappeared but...i just want to avoid on tuesday the same problem. Maybe adding more ligh to the scene?
 
Ideally you would add more light, however, raising the ISO to ETTR should yield less apparent noise. Flat profiles raise the noise floor, and ETTR helps counteracts the higher noise floor.

With that said, I don't think that your scene warrants a flat profile, as it doesn't appear to be a high contrast scene; just use the Standard profile with the contrast dialed down and expose for the skin tones.

Here's another thread started by Ebrahim Saadawi that's worth reading: ETTR: The Ultimate Exposure Technique?

How are you exposing your camera? If you got a field monitor, you should be able to use false color and zebra stripes to gauge exposer.
 
Hola Imamacuser,
i missed your post. I just purchased a new Feelworld monitor, i was exposing just checking the lcd of the camera. Do you think that for interior interviews i could go with a Standard Profile dialing all the way down the contrast?
 
You might not even need to turn the contrast all the way down, run some tests and see what looks good to you. For indoor interviews, under controlled lighting, I think it's good to shoot close to the Rec.709 standard.
 
Imamacuser thank you for the suggestions but to be sure in what to do for interior shots :

- should i set flat 11 Profile and on settings of the profile should i try to raise up (after tests) the contrast?
- To get close to the Rec.709 standard should i do what i wrote above?
Thank you so much for your kind help
 
Select the "Standard" profile and turn down it's contrast, this will get you pretty close to Rec.709.

The only time it would make sense to shoot in a flat profile indoors, would be if there was a window behind your subject and you were trying to hold onto some of the highlight detail outside of the window. That kind of situation warrants ND gel on the window and a super bright key light, be that might not be practical in all circumstances.

Flat profiles can be tricky to grade, so it's best to use ones that have a corresponding corrective LUT.
 
For indoor shots, under controlled light, don't use the Neutral profile, use the Standard profile with the contrast dialed down a little. To do this on my D7000, I select menu / Shooting Menu / Set Picture Control / Standard / Contrast. Run some tests with different contrast settings and see what you like.
 
You might have seen this already, here's the skin tone shot from the D7000 in the Zacuto 2011 Great Camera Shootout. Nikon's can produce a great image when they're exposed correctly.

Set your field monitor's zebras between 70 - 80 depending on the subject's skin tone, and adjust your camera's exposure till the zebra strips just barely start to register on the brightest part of your subject's face.
 
Hallo, i wanted to show you what i did: i dialed down the contrast almost to zero with the Standard profile as you suggested me. The noise grain with the flat 11 of thd D7100 disappeared...
I filmed in the darkness of the pits and i'm pretty happy for the results. Could you tell me your opinion ?
Thanks for your time
https://www.facebook.com/watch/?v=3843656825732903
 
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