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-   -   The War against Video Noise (https://www.dvinfo.net/forum/canon-xh-series-hdv-camcorders/239388-war-against-video-noise.html)

Christopher Warwick July 20th, 2009 06:16 PM

The War against Video Noise
 
I'm not talking about low light situations here, I'm talking about well-lit scenes. I invested in the Lowel Rifa 55 DVcreators kit. So I have a Tota, Omni and Pro light as well as the Rifa which is great for interviews...

But say we're lighting for night. A bedroom scene for example. Everyone knows it still has to be well lit, but I am finding that even with a well lit scene, I'm getting pretty awful video noise.

My set up is as follows, the Letus adapter which has a fast lens on it. My AGC is off of course and my gain is set to 0db. I use the Tota and Omni lights in adjacent corners of the room with half CTB gels on each.

The room is lit well, but I need to darken the image now. I set the shutter at about 180 and the close the iris some to darken the shot. I just know you're gonna tell me to open her up... But how to get that dark look otherwise? The image looks grainy/noisy with these settings.

Michael Hutson July 20th, 2009 06:53 PM

Use the ND filters first to get you in the ball park, then use the iris ring. sweet spot around 4.8-5.6.

Marcel D. Van Someren July 21st, 2009 07:43 AM

I recommend that you shoot the scene fully lit and do not try to darken it. Rather, darken the footage in post. I recently shot a bedroom scene that was supposed to be at night. I lit the scene as if it were daytime. I darkened it in post and created the illusion that it was shot in a dark room. In the same project I also shot an outdoor night scene in full daylight and created the illusion of night in post.

Christopher Warwick July 21st, 2009 09:13 AM

Thank you Marcel and Michael for your informative posts. I have tried both methods. I do find that no matter what I do (adding ND 1/6) or not, if I keep the iris open and shutter at 1/60, I still get noise (Frame Grab 'A').

On the other hand, if I shoot it well lit and change it in post, I can't seem to get the same realism. Mind you thay is not to say it isn't achievable. I was using brightness and contrast settings to make the image darker in post (Frame Grab 'B').

http://i31.tinypic.com/2cd8tqw.jpg

That's not to say the noise is very bad, but I can still see it. Which image looks better? Perhaps it is simply a matter of taste, but getting the image correct in production is surely better than playing around with it in post?

Michael Hutson July 21st, 2009 09:35 AM

Chris,

Here is a link to a trailer that was shot with a xha1(stock lense). A HV20 was used as well(the Lighted shots)..shot at the same time(2 cameras). The HV20 shows the real lighting, the xha1 had nd filters on and the Iris closed down some.

YouTube - GRIMM HD TRAILER NEW

I am curious if it is a preset that you are using.(Just thinking out loud)

Marcel D. Van Someren July 21st, 2009 09:51 AM

Quote:

Originally Posted by Christopher Warwick (Post 1174450)
Thank you Marcel and Michael for your informative posts. I have tried both methods. I do find that no matter what I do (adding ND 1/6) or not, if I keep the iris open and shutter at 1/60, I still get noise (Frame Grab 'A').

On the other hand, if I shoot it well lit and change it in post, I can't seem to get the same realism. Mind you thay is not to say it isn't achievable. I was using brightness and contrast settings to make the image darker in post (Frame Grab 'B').

http://i31.tinypic.com/2cd8tqw.jpg

That's not to say the noise is very bad, but I can still see it. Which image looks better? Perhaps it is simply a matter of taste, but getting the image correct in production is surely better than playing around with it in post?

"A" definately looks better than "B" but you can achieve the same look in Post and it's not very difficult for a scene like in the grabs. Besides brightness and contrast, you'll want to lessen the saturation. You may also have to manipulate the gama curve. And if you're doing an outdoor night scene, you'll want to add a touch of blue to the scene.

Dennis Murphy July 23rd, 2009 02:58 PM

Quote:

Originally Posted by Christopher Warwick (Post 1174450)
I was using brightness and contrast settings to make the image darker in post (Frame Grab 'B').

Try and stay away from using brightness and contrast as it is global across the the image in terms of it's effect - use curves instead.

Kevin Duffey July 23rd, 2009 04:47 PM

curves and levels are your friend.. and hue/saturation. One thing I try to do is set the display to each color, green first, then blue, then red, and adjust the gama and ins/outs of the shadows and highlights, then put it back to full RGB and see how it looks, then from there adjust a little bit more.


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