GemiZ

[rand thompson]

HaHa, Spinal Tap was a film I never saw all way to the end, I am going to have to make a point of watching it since seeing this. I always thought that the band was a parody of Iron Maiden

 

[Zeb B]

HaHa, Spinal Tap was a film I never saw all way to the end, I am going to have to make a point of watching it since seeing this. I always thought that the band was a parody of Iron Maiden

Simply one of the best movies of all time. I shop from Norman's Guitar shop where they loaned Rob Reiner the gear for the movie and have made back like $100M over the years in tee shirts sales and tourist traffic. Oh and, the Big Co Studios are assholes but might have their day of reckoning in the near future:
https://www.rollingstone.com/movies...allows-400-million-lawsuit-to-proceed-253435/

The creators got like $200 total from the movie which pissed off Harry Shearer so shits about to get real ;-)

 

[rand thompson]

Zeb,

I never knew that, and I saw this;

"the Spinal Tap co-creators received just $81 in merchandising income and $98 in musical sales income over the last few decades from the cult 1984 mockumentary."


Now that's fucked up! I hope those guys get everything that they deserved from this iconic film, and then some on top of that!

 

[rand thompson]

Zeb,


Here is a redo of the fourth image. I corrected the Fluorescent lights from green to a more neutral white and I left the tungsten colored lights at both sides of the store alone to keep their color as is. But in doing so, I added a shitload of noise to the blue sky. I regraded the image a couple more times the same way in Redcine-X and noticed something from looking at the different channels individually.

The Green channel appeared to be the least noisiest.

The Red channel appeared to be the second least noisiest.

The Blue channel appeared to be where the noise was having a party.

So in the future I will be trying to use less blue in to correct an image because it seems to induce more noise than the Red or Green Channel. For better noise reduction in noise reduction programs target the blue channel if it lets you target a specific channel for reduction.

 

[rand thompson]

Zeb,


I looked at your image straight out of camera in Redcine-X also.

Green

Red

Blue

It appears that the more you either need( for white balance issues) or Choose( for creative reasons) to correct an image using the "Blue" channel, the more noise you will add to the overall image but especially to the "Blue" channel. The noise in the "Blue" channel in the "uncorrected for Green" original image looks a lot better.

 

[Zeb B]

Hey Rand,
Good detective work! Yeah, the Blue channel is always the problem child for reasons Phil or Marc can explain. I'm away from the desktop computer today but will look into the R3D's a bit deeper tonight.

Image #4 Toon Town ;-)

 

[rand thompson]

Zeb,

Alright then! that image looks great! like straight out of some type of freaky horror movie.

 

[Michael Tiemann]

[...]

It appears that the more you either need( for white balance issues) or Choose( for creative reasons) to correct an image using the "Blue" channel, the more noise you will add to the overall image but especially to the "Blue" channel. The noise in the "Blue" channel in the "uncorrected for Green" original image looks a lot better.

Yet another reason why, when one has the chance to control lighting oneself, it's a great idea to use daylight-balanced lights whenever possible, and to think very carefully about how to make "cool" and "warm" relative to 5600K rather than 3200K.

 

[rand thompson]

Micheal,

Yeah, I see what you mean. So for better to best results, HMI with high CRI rating or at least a simple Daylight balanced solution with a reasonably high CRI rating. So Fluorescents with a very high CRI and with very good control of Green spikes. So is that about what you are saying?

 

[Michael Tiemann]

Micheal,

Yeah, I see what you mean. So for better to best results, HMI with high CRI rating or at least a simple Daylight balanced solution with a reasonably high CRI rating. So Fluorescents with a very high CRI and with very good control of Green spikes. So is that about what you are saying?

Yes--both high CRI and 5600K temperature. Of course, all bets are off when you are doing available light such as this particular scene. But when one does have control...you can really see why you'd want to exercise that control.

 

[Zeb B]

I heard that most color science is best with tungsten since that is what the Studios had until recently. Counter intuitive since the noise lives in the blue channel so feed it more blue light. Right? I not so sure about that; the sky in #4 has plenty of blue light and plenty of noise in the blue channel.

 

[Michael Tiemann]

Here's a lengthy discussion from many years ago. Not sure if much has really changed, as silicon is notoriously less sensitive to blue light than red light:

The RED makes great images but it’s very noisy, particularly under tungsten light. Its native white balance is 5000k, and under 3000k illumination (which contains a lot more red and a lot less blue than daylight) the blue filters on the sensor don’t pass enough light to give the blue channel a healthy exposure. That the blue channel is underexposed is nothing special; this is a problem with every camera. It’s just a bit more severe with the RED.

 

[rand thompson]

Zeb and Michael,


Yeah, I think I'm going to be doing a lot more research on this. Because the "Blue" channel has been my buddy in a shitload of grades, HaHa, when Red and Green have been fighting the "blue" channel would come along and settle the argument.

 

[Zeb B]

Yeah the silicon blue sensitivity thing explains the noise, but I still think that color science still has one foot in the tungsten world from the 100 years of experience with 20K's ;-)

 

[rand thompson]

Zeb,

I was going to try and look at some Sony Venice and Arri raw footage in their respective Raw programs and see how they distribute noise in their RGB channels. Hopefully the programs will let you the individual channels.

 

[Aaron Lochert]

and see how they distribute noise in their RGB channels

Just do it in Resolve. Add a splitter/combiner node (Color > Nodes > Add splitter/combiner node, or alt+y) and click the highlight button (magic want icon, upper left of playback window). You'll notice it split the node path into three nodes (r, g, and b). Click on each node and the highlight button shows you what just that node is doing, so now you have a monochromatic representation of the channels, just like you saw in RCX.

You should see the same noisier-blue-channel phenomenon in just about every camera below 5600K.

You can also use this splitter/combiner to apply noise reduction to the different channels in different strengths, by the way.

 

[Zeb B]

I'll try and shoot the still life with two different light sources and upload the R3D's. Only have Hexolux LED's with me, but they pretty solid for wavelength imho

 

[rand thompson]

Just do it in Resolve. Add a splitter/combiner node (Color > Nodes > Add splitter/combiner node, or alt+y) and click the highlight button (magic want icon, upper left of playback window). You'll notice it split the node path into three nodes (r, g, and b). Click on each node and the highlight button shows you what just that node is doing, so now you have a monochromatic representation of the channels, just like you saw in RCX.

Aaron,


Thanks! I can't even remember when was the last time I used a Splitter/ Combiner node in Resolve

 

[rand thompson]

I'll try and shoot the still life with two different light sources and upload the R3D's. Only have Hexolux LED's with me, but they pretty solid for wavelength imho

Zeb,


That would be great! Thanks

 

[rand thompson]

Here are two separate tests on Sony X-OCN clips that Luigi provided months back.


First Test

Format: Sony X-OCN
Color Space: S.Gamut3.Cine
Gamma: S-Log3

As Shot Settings

Temperature:3200K
Exposure: 4950

"Low Light Mode"


Conversion


S-Log3-S.Gamut3.Cine_To_S709_V200( No additional Grading was done)


Image

Red Channel

Green Channel

Blue Channel