user18089: I saw a brilliant thread talking about why the colour red is noisy in post:
Why does the color red always appear pixelated on TV and videos on the PC?
I found this incredibly helpful in understanding why red appears that way. What I want to know is what can you do when filming dark red to avoid high levels of noise?
I was recently filming a museum installation and all the walls were dark red brick. This museum was inside so the natural light was very limited, so naturally I shot at my highest aperture (at the time was 3.5) and set my ISO as low as possible. My camera hasn't got the best sensor but I just wondered if there was an explanation or other tips as to what to do when you know you're in a location with lots of dark red.
Cheers
Lav

user6207: Filming any light that is strongly a single color is likely to produce a lot of noise because it's absorbing more light. (In your case, the red brick is absorbing green and blue, leaving only the red.) 
Furthermore, if you're filming with a Bayered CMOS sensor like the ones found in most phone cameras and DSLRs, the sensor captures twice as much green light as it does red or blue light. The sensor sites are generally set up in a red-green-blue-green order.
So you're starting with less light reflected from the material and your collecting less light at the sensor. Any noise is going to be magnified because the resolution of the red channel is half that of the green channel, too. So how do you avoid it? You have a few options:

Supply more light to the scene
Use a camera with a sensor that has good low light response
Apply noise reduction in post
If you can change out the background (either by replacing it or filming from a different angle), that might be better.


18089: <p>I saw a brilliant thread talking about why the colour red is noisy in post:</p>

<p><a href="https://video.stackexchange.com/questions/5533/why-does-the-color-red-always-appear-pixelated-on-tv-and-videos-on-the-pc">Why does the color red always appear pixelated on TV and videos on the PC?</a></p>

<p>I found this incredibly helpful in understanding why red appears that way. What I want to know is what can you do when filming dark red to avoid high levels of noise?</p>

<p>I was recently filming a museum installation and all the walls were dark red brick. This museum was inside so the natural light was very limited, so naturally I shot at my highest aperture (at the time was 3.5) and set my ISO as low as possible. My camera hasn't got the best sensor but I just wondered if there was an explanation or other tips as to what to do when you know you're in a location with lots of dark red.</p>

<p>Cheers</p>

<p>Lav</p>
 6207: <p>Filming any light that is strongly a single color is likely to produce a lot of noise because it's absorbing more light. (In your case, the red brick is absorbing green and blue, leaving only the red.) </p>

<p>Furthermore, if you're filming with a Bayered CMOS sensor like the ones found in most phone cameras and DSLRs, the sensor captures twice as much green light as it does red or blue light. The sensor sites are generally set up in a red-green-blue-green order.</p>

<p>So you're starting with less light reflected from the material and your collecting less light at the sensor. Any noise is going to be magnified because the resolution of the red channel is half that of the green channel, too. So how do you avoid it? You have a few options:</p>

<ol>
<li>Supply more light to the scene</li>
<li>Use a camera with a sensor that has good low light response</li>
<li>Apply noise reduction in post</li>
<li>If you can change out the background (either by replacing it or filming from a different angle), that might be better.</li>
</ol>
