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Noisy 120 fps footage

A

Aiden K.

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Maybe I'm doing something wrong, but whenever I shoot in 120FPS @ 1/24 shutter, my footage is very noisy, and not small typical noise you'd see when you bring the iso up to 1000. This is BIG chunky noisy. Almost like looking at a ton of low res images, blown up and thrown into a timeline. I do believe I've seen other's slow motion footage that looks just as beautiful as the normal image quality RED produces on 24fps @ 1/24 shutter.

Am I doing something wrong? or is there a procedure that anyone shoots their hispeed stuff in they can document for me? Thanks!
 
Are you giving it enough light - ISO 1000 is probably too high for RED to avoid noise especially if you're shooting with tungsten light, and at 2K resolution, noise will be chunkier.
 
Maybe thats what it is. I brought it back down to 320, then its under exposed, but I still see the big chunky slow-mo noise. If I have enourmous amounts of light, will that cure the big chunky noise?
 
Well, then it's probably underexposed... Remember that noise will look a bit more than 4 times as bad in 2k as in 4k when viewed @ 1:1 @ 1080. Because you only use 1/4 of the pixels and it will not be scaled down.

That said, there's a couple of things you can do, depending on the shot.

If it's shot under tungsten, try to lower the ISO to 250 or 160, set whiteballance at 5600 and use brightness to lift the image and contrast/ an s-curve to find it back.

Then, after development, you should be able to ballance the image without messing up the blue channel which (still under build 20+) is the main source of noise, and you can avoid blowing the red channel (which is the main reason for bad skintones. Setting the WB at 3200 or lower can quickly lead to a blown red channel without any of the meters telling you what's going on...)

A still frame would help.


But the main moral is: A 2k frame is more noisy than a 4k.
A poorly exposed 2k frame is much worse than a poorly exposed 4k frame.

On another note, how can you have 1/24 shutter on a 120 fps shot?

G
 
Gunleik Groven said:
If it's shot under tungsten, try to lower the ISO to 250 or 160, set whiteballance at 5600 and use brightness to lift the image and contrast/ an s-curve to find it back.
Click to expand...

Just tried this option. The footage looks virtually the same. same noise, same quality. But thanks for trying.
 
Deanan said:
The max open shutter at 120fps would be 1/120th sec.
Click to expand...

I was mistaken, because when I set the framerate to 120, it just makes the 1/24 RED and must "behind the scenes" set it to 120. Or am I just totally overlooking something?
 
ericyoung said:
Are you giving it enough light - ISO 1000 is probably too high for RED to avoid noise especially if you're shooting with tungsten light, and at 2K resolution, noise will be chunkier.
Click to expand...

Wait a mintue tungsten light gives a nosier than HMI or Florescent (kinos)
wow how is that?
 
This is pretty normal. 2k and high frame rates are the worst enemies of clean footage.

You will needs tons of daylight balanced light.

I have done outdoor shoots and still get chunky noise.

I think Epic will be a thousand times better, first because you can shoot high rates at full resolution, plus the extra latitude.
 
Right so I guess every penny I make with my HVX / 7D combo should go toward lighting, and then an EPIC?

From what I understand now... It seem that 1080p will look good at 720 x 480 2k will look great a 720p 4k will look lovely at 1080,
because we are seeing less and less of the individual pixels less of the fine details are seen because the footage is re-sized sooo much.
 
Basically, anything you shoot with will be starved of light when you get to 120FPS, it's just that most devices won't ever get there!

And yes, oversampling is your friend. True in audio as well, who can hear 24-bit 96k when our ears only go to about 20k? All about oversampling for harmonics and nuance.

When all that lovely resolution is squished into a little package, it looks much better as a result.
 
Understood that's why those days with my vx2100 compressed for web didn't look much different (was using 640x400).

So over deliver and then down convert to what the client needs. Shoot in HD but press it down to SD. I see your point with 24bit sound (more information is held unto when that is done).
 
Also 3K 2:1 resolution Redcode 28 is a good compromise if you want slo-mo but can live with 60fps as the max frame rate.
 
ericyoung said:
Also 3K 2:1 resolution Redcode 28 is a good compromise if you want slo-mo but can live with 60fps as the max frame rate.
Click to expand...

Strongly agree. Just shot a bunch of 3K 2:1 RC28 on Sunday, viewed it on an 8' Stewart Firehawk SST from a Sony Pearl 1080P SXRD projector. It was a hair softer than 4K RC36 on the projection but on the 23" eCinema you couldn't tell.

When I have needed max framerate and shot 2K@120fps the footage is usually compelling because of the extreme slo-mo but on a decent sized screen it looks a bit softer - typically I just sharpen it a bit in post and it intercuts just fine. FWIW I use Scratch with a full res debayer and, if the clips are well exposed, have found the noise levels very low even in 2K footy. YMMV.

Cheers - #19
 
Hey Aidan,

I know what you're talking about. I searched this forum a lot to find an answer for this. I've experienced this sometimes. The 120 fps footage show many compression artifacts (blocks) and a lot of aliasing on the edges. Almost unusable if the final is a 1080p. I have run many tests it it simply has no rule for this to happen. I've shot exactly the same thing with 2 two different bodies and got different results. I think it has to do with the fact that REDCODE records in VBR, and maybe a different drive or drive cable has different transfer rates.
I have some empirical results and some tips that sometimes helps:

When shooting 120fps always use:

A fresh new RED DRIVE (100% media)
A fresh new battery
Short drive cable
Super 16mm lenses
And overexposing sometimes helps (I use ISO 100)

Hope this helps

Eduardo
 
Wow all this is good to know... I can't wait till I get my Red.
 
I've always heard to use a lot more light with faster frame rates, even with film cameras. But then again, when I've done 2K 120 fps it looks the same as my 4K 24 fps footage. I didn't change my lighting setup or anything either. I dunno.
 
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