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View Full Version : How to eliminate noise in video recording?



_MD_
03-14-2010, 06:56 PM
Please help! I started doing HD recording with my canon 7d, but I get a lot of noise while recording a video in low lighted environment (mostly indoors). I have to start off by saying that I'm only a beginner and I just managed to reduce noise in still shots by shooting at a longer shutter speeds with ISO100... But this method is not applicable for video.





I use 17-55mm 2.8 and here's the settings I've tried (all manual):


Aperture - 2.8
Shutter - 30
ISO tried 100 (comes out very dark, noise not visible) and up to 2000 (bright, but lots of of noise)


So any advice as to how I can eliminate noise for indoor videos? Maybe it is done at post-productions level? Or maybe I should use filters?! I never used any... anybody wants to enlighten me what they are for? UV? Polarizing? ND??? Thanks so much! =)

jcrowe87
03-14-2010, 07:09 PM
I sadly will say that the majority of the problem is simply not enough light. Nearly all videos you see that are crisp and clean have external light sources, or are shot with very fast lenses, F1.2 or even wider. Once noise is in your images from using high ISOs there is little you can do to rid yourself of it. If you are serious about video, investing in some type of lighting may be the best thing for you, other than that, try to work with what you have at your disposal.

_MD_
03-17-2010, 09:59 PM
***bump***

Daniel Browning
03-17-2010, 10:06 PM
I think jcrowe answered your question pretty well already.






So any advice as to how I can eliminate noise for indoor videos?





You can't. When light is low or poor quality, you get noise. You can try to hide it by using NR, increasing contrast (clip blacks), reducing saturation, etc., but personally I would not change my desired rendering just to reduce noise.



Maybe it is done at post-productions level?


You can use various types of noise reduction in post, but they all have negative drawbacks (such as loss of resolution for noise reduction).



Or maybe I should use filters?!


That is not going to reduce noise. At best it will reduce clipping.



I never used any... anybody wants to enlighten me what they are for? UV? Polarizing? ND??? Thanks so much! =)


None of those are any use for reducing noise in low light.


Good luck.

Sean Setters
03-17-2010, 10:45 PM
For example, this video was shot at [I believe] ISO 200. I was testing out the different types of frame rates and while trying to film an intro for my website. The light hitting Amber comes from a 1000W continuous light, diffused by an umbrella, to the left of the camera (you can even hear the fan of the light if you listen closely).


[View:http://www.youtube.com/watch?v=v7PrToV3uCY:560:340]
<center></center>

Keith B
03-17-2010, 11:05 PM
That's hilarious!

Sean Setters
03-17-2010, 11:36 PM
By the way, the intro to my website is terrible. I just wanted to film one to see if it was possible to embed the youtube video. It worked. Now I need to film a new one while I'm actually on a shoot...the backdrop of model, umbrellas, strobes, and camera will make a much better impression, I'm sure.

_MD_
03-17-2010, 11:46 PM
Thanks for your replies.





I guess what I'm trying to figure out is how to use my camera filming at night.





Let me show you an example. This video was recorded at f/2.8 shutter 30 and iso 2000 (anything lower than 1000 iso is waaay too dark)


Test video ("http://tinypic.com/r/214dxfr/5)


(the quality on tinypic is too low, if you want, you can download a 40mb wmv 1080p video here ("http://www.yourfilelink.com/get.php?fid=535937))





But this is what I am aiming for


Another night in beijing. ("http://vodpod.com/watch/2309706-canon-7d-movie-another-night-in-beijing-on-vimeo)





Even if they used different lens, can the aperture difference between my 2.8 and their possible 1.0 be THAT substantial for recording a crispy sharp videos? Any tips on how to film like this at night? Thanks again. :)

Sean Setters
03-18-2010, 12:09 AM
For one thing, it's very difficult to focus. You might find the best results come with manual focus. And keep in mind, he's showing many clips, and each one ever so briefly. So, in effect, he's picking the best of what was shot. Plus, it looks like a busy, bustling street full of nightlife (and light).


Play around with it...keep trying. I'm sure you'll find out what works best (and what's required for the best results). Then you'll be able to tell us how to do it!


:-)

DavidEccleston
03-18-2010, 12:27 AM
First, I've heard many cameras have worse noise at "tweener" ISOs (ie: the ones that lie between the regular 100, 200, 400, 800, 1600, 3200). Dropping to ISO 1600, or even moving up to ISO 3200 may reduce noise.


Going from f/2.8 to f/1.4 would drop the ISO by 4x (from 2000 to 500), which would greatly reduce the noise. You'd need a fairly wide angle lens though, to have any depth of field to work with at that sort of aperture though. A 35mm f/1.4 on a 7D would give you a foot of sharp focus at a distance of 8.5ft or so. (Using DOFMaster ("http://www.dofmaster.com/doftable.html)to check). A 24mm f/1.4 would give you a foot of sharp focus at 6ft or so. If you wanted a deeper DOF, you'd need to stop down the lens, and increase ISO again, or find some way to light the scene (or upgrade to a 1DmkIV. Vincent LaForet's Nocturne was with a mkIV at ISO6400 with a quick post process noise reduction, and looks fantastic).





Depending on the quality of the video resizing on the camera, you may be able to do better by shooting at a larger resolution. Shoot at 1080p at ISO 1600, then noise reduce and downsample to 720p. The downsampling should help mask and loss of sharpness from noise reduction.