Blackmagic Forum

Hi all,

Have you experienced such banding (not sure how to call it)? You can check the right half of the screen where it's more prominent:


Here's a google drive link with the original image: https://drive.google.com/file/d/1iy-mzg ... sp=sharing

The camera is DJI's Ronin 4D, not sure what the ISO was.

Any ideas on how to fix this?
Thanks in advance

Google drive link is broken unfortunately.

Robert Niessner wrote:Google drive link is broken unfortunately.

my bad, here it is: https://drive.google.com/file/d/1iy-mzg ... sp=sharing

Looks like you didn't give much light to the camera. To really analyse what it is, please post some video, not just a still.

Uli Plank wrote:Looks like you didn't give much light to the camera. To really analyse what it is, please post some video, not just a still.

True indeed - was caught up in the moment and was looking more at framing, etc. than scopes.
Will cut a sample and post it tomorrow, sorry for posting a still.

Here's a video snippet of the scene: https://drive.google.com/file/d/1G58jwR ... sp=sharing

Massively underexposed. Could be an electronic interference or a light source with the wrong frequency coming in as scattered light. Difficult to judge, since you didn't post a camera original.
If you want dark images, expose higher with strong contrast and pull them down in post. Much cleaner. For this case at hand, you could give the flicker filter a try.

Miro Markov wrote:Here's a video snippet of the scene: ...

With a caveat that I am very inexperienced (especially when compared to guys that have already contributed) whenever I see in shots I took flicker induced by lighting gear it always "travels" in same direction across the scene with same "rate of speed", not follows brighter area of the scene (your face) as it moves up and down. Which camera was this taken with?

Uli Plank wrote:Massively underexposed. Could be an electronic interference or a light source with the wrong frequency coming in as scattered light. Difficult to judge, since you didn't post a camera original.
If you want dark images, expose higher with strong contrast and pull them down in post. Much cleaner. For this case at hand, you could give the flicker filter a try.

Yup, i know... like i said, caught up in the moment, couldn't reshoot... tricky situation all around. No lights on set, super early in the morning, all that jazz. I can also post the camera original, but that'll be a d-log.
I'll check the flicker filter - thank you for the notes Uli.

4EvrYng wrote:

Miro Markov wrote:Here's a video snippet of the scene: ...

With a caveat that I am very inexperienced (especially when compared to guys that have already contributed) whenever I see in shots I took flicker induced by lighting gear it always "travels" in same direction across the scene with same "rate of speed", not follows brighter area of the scene (your face) as it moves up and down. Which camera was this taken with?

It's Ronin 4D, the 6K sensor, an early firmware.

Miro Markov wrote:

4EvrYng wrote:

Miro Markov wrote:Here's a video snippet of the scene: ...

With a caveat that I am very inexperienced (especially when compared to guys that have already contributed) whenever I see in shots I took flicker induced by lighting gear it always "travels" in same direction across the scene with same "rate of speed", not follows brighter area of the scene (your face) as it moves up and down. Which camera was this taken with?

It's Ronin 4D, the 6K sensor, an early firmware.

You might then want to double check with other Ronin 4D owners, especially if you didn't use any artificial lighting (if I am interpreting your new post correctly that you didn't).

it's the sensor scanning unable to scan underexposed info and get compressed out of the processor ( chip). similar to curved airplane propellers when shooting with slow chip processing.

exposing it correctly would probably fix it so you can't see it...it would be helpful if you paid attention to your exposure and shutter speed and choice of codec etc. but mostly for you I would pay attention to the amount of light you have to shoot any kind of photograph.

It really was an edge case - 60fps, 1/120, 422 HQ, ISO high as a kite, couldn't use lights, it was dark outside, i believe i was shooting @ 1.8 and i've done this before, but XT4 (for example) never introduced such artifacts - that's why i was wondering if it's the 4D sensor or something...

Miro Markov wrote:It really was an edge case - 60fps, 1/120, 422 HQ, ISO high as a kite, couldn't use lights, it was dark outside, i believe i was shooting @ 1.8 and i've done this before, but XT4 (for example) never introduced such artifacts - that's why i was wondering if it's the 4D sensor or something...

Is it sensor and is it an issue that does matter? Maybe, and maybe it doesn't.

On one side if you watch reviews of BMCC 6K they've been pointing out something similar to your example in heavily underexposed shots.

On the other side, from what I have seen people sharing files from practically any camera will start falling apart once heavily under/over exposed and question isn't will they fall apart, but how soon. If you watch YT reviews by Josh Sattin, for example, he compared over/under latitude from many cameras and many of them are more or less equally resistant but once they do reach limit start falling apart in different ways, none is perfect. So you will need to ask yourself how many stops of under exposure you had there, have you exceeded what is reasonable limit, and what experience other owners of same camera have when using it in same way.

Even a massively underexposed Arri will show similar effects if you have a few contrast edges in the frame.
Don't starve your sensor of light. Electronics are very different from film in this respect: a film negative will be empty if it's dark. An electronic sensor will produce noise of all kinds, random noise and FPN anyway (which this obviously isn't) and also stray signals from other high-frequency devices (which may be the Ronin).
So, even if I don't like that phrase: try to fix it in post as much as you can.