Scarlet / Noise

[Stephane Marino]

Hi,

I would like your opinions on the noise I have with my SCARLET :
In the attached R3D snapshot, do you think the amount of noise is normal ?
A001_C003_0724JI.0000052F.R3D

I shot with a Canon mount, 50mm, F4, 1/48 shutter, ISO 800 and did a black calibration just before.

Thanks for your help.

[Ryan Emanuel]

Hi,

I would like your opinions on the noise I have with my SCARLET :
In the attached R3D snapshot, do you think the amount of noise is normal ?
A001_C003_0724JI.0000052F.R3D

I shot with a Canon mount, 50mm, F4, 1/48 shutter, ISO 800 and did a black calibration just before.

Thanks for your help.

First off my opinion is not a professional one, I just mess around with my scarlet a lot. I would say after looking at the waveform you need to crush the blacks for the piano. You have that piano at 14% IRE. Thats above the 9-12% IRE red even defines as Dark Grey. I think Black (not True Black) is supposed to be around 3-5%IRE and when I crushed the blacks down It looked pretty clear to me. If you leave dark areas where the should be there will be no noise, but if you map them up into the midtones you get noise.

My experience is that with RAW you can push you midtones anywhere you want, but 5-7 stops under middle grey can move only about a stop before introducing noticeable noise into the image. The difference between 3-5%IRE and 14% IRE is more than a couple stops. If I got it wrong, guys please let me know.

[William Robinette]

Yes. It looks normal.

[Fernando Tufiño]

Try bringing down the ISO in Red Cine X.

[Stephane Marino]

Thanks !
I know I can lower the ISO or play with the curve to crush the blacks, but I just wanted to know if as it is, at 800 iSO, the result is normal for the SCARLET.
I just found this :
http://www.gunleik.com/tests/alexmx/...roduction.html
which make me understand that I should lower the ISO on set in lowlight if I want to avoid noise......

[Casper Warnich]

The window makes the histogram look well exposed, but everything else is actually underexposed – especially the piano.
If you expose at 800 it is very important to expose to the right – or expose at 320-400 iso and watch your highlights.
Just my 2 cents

[Stephane Marino]

I just read this too :
http://www.red.com/learn/red-101/exp...th-red-cameras
It also says to raise ISO to protect highlights and decrease ISO in low-light... exactly the contrary of what I was thinking.
It says that with higher ISO the middle gray is mapped to a darker tone (more tonal range for highlights), but then it should give a darker image no ???

HELP... :)

[Graeme Nattress]

When we're talking about mid grey as recorded in the R3D the whole concept of ISO is that the correct ISO will always map that recorded mid grey to an mid grey in the final image. If that mid grey is recorded at a low code value you have more code values above it, hence more highlight protection, but more noise as the mid grey is recorded darker. The amount of gain the ISO control applies is always the right amount to map that mid grey to the mid grey in the final image.

Increasing ISO just makes the image brighter. If you retain the same image brightness by compensating with ND or aperture, you now have the same brightness for mid grey in the final image, but the mid grey code value is recorded at a lower value. As it's a lower value, you now have more available code values above it for more highlight information.

Graeme

[Mark Toia]

When we're talking about mid grey as recorded in the R3D the whole concept of ISO is that the correct ISO will always map that recorded mid grey to an mid grey in the final image. If that mid grey is recorded at a low code value you have more code values above it, hence more highlight protection, but more noise as the mid grey is recorded darker. The amount of gain the ISO control applies is always the right amount to map that mid grey to the mid grey in the final image.

Increasing ISO just makes the image brighter. If you retain the same image brightness by compensating with ND or aperture, you now have the same brightness for mid grey in the final image, but the mid grey code value is recorded at a lower value. As it's a lower value, you now have more available code values above it for more highlight information.

Graeme

Once again Graeme you have me pulling a face like I have just seen a David fincher movie in reverse... :)

I would have said ( in my simple way) It's simply under exposed and the more you pull out detail in the dark areas the noisier it gets. Hence why I shoot at 320 (but I protect my highlights) , When I shoot at 800 I also see noise. Not that it worries me, because I like a little noise. :)

[Graeme Nattress]

The small amount of noise you get at ISO800 is generally very good for an image.

ETTR is a different exposure method to "ISO". It doesn't necessarily mean you'll end up with a differently exposed image, but it's another route to get to optimum exposure.

Graeme