Perfectly black background

[Aymen]

I'm currently trying to make a video of a candle in the dark. But when I watch the video on the pc the black background has much noise and it's not perfectly black. I was wondering if you have some advice for me on how to get the background all black and smooth. Would I have to do it through editing the video after shooting or is there something I have to do (with light maybe) while shooting? Thanks in advance for your ideas and suggestions.

Aymen

[jagabo]

Assuming your background is dark to start with, use manual exposure on the camera to make the background totally black. There will probably still be a little noise in the background. To fix the video after it's been recorded you can probably increase the contrast or decrease the brightness. The dark parts will get darker and hopefully all the dark noise will become perfectly black.

Can you post a short sample of the video? Or at least one image?

[poisondeathray]

You probably need a better camera with higher sensitivity. What are you using ?

[Aymen]

Thanks a lot for your ideas. I have a Canon XL1 and acttally I played with the iris and the shutter speed but either I get the candle with a noise background or I get too much light so that you can see the candle and everything that's behind. Actually what I want is to have the candle that lights a worldmap underneath, but all the other surrounding perfectly black. So that's why i wonder how they do in professional movies with a perfect background and smooth objects in front of the background.

http://a.imageshack.us/img534/7697/vlcsnap2010080700h43m15.png
http://a.imageshack.us/img237/3369/vlcsnap2010080700h45m01.png those are images of the video as it is

http://www.youtube.com/watch?v=_8w5liuOf1E
http://www.youtube.com/watch?v=fEyZLUC5KSU&feature=related this is how I would like the black to be

and

http://www.vimeo.com/8963500 do you have any idea how to get this effect on the video, a bit blurry and smooth contrast

Thanks a lot for everything

[jagabo]

I'm not exactly sure what you're looking for but:

A little darker (brightness down, gamma up):

The map is still visible but the background is pure black (except a few white spots).

Similar but with a very strong 2d noise reduction filter:


More gamma (brings out more dark detail), no noise reduction:


A lot: (brightness way down, contrast way up):

The map and the rest of the background are pure black.

[nic2k4]

Are you using a velvet background? Gives the best results when trying to get a dark background with no reflections. Your biggest problem is the image sensor, electronic sensors have a "very" limited dynamic range. You're trying to capture very bright (the flame) and very dark (the background) in one shot; your camera can only do a fraction of that range. One solution is to do a composite image, film the candle on it's own with a blue/green screen and do the same for the map, then merge the 2 toghether.

The professionals use film.

[MOVIEGEEK]

Professionals also use backlighting.

I recommend using a low wattage light from above then set the ISO lower, this will lower grain and keep the background dark. A nite-light(4w) mounted a few feet above the candle would work and wouldn't cast a shadow.

[jagabo]

I don't know about the Canon XL1, but the better digital sensors are now meeting or exceeding film's dynamic range. Some good comparisons: http://www.zacuto.com/shootout

[Aymen]

Hi

Thanks a lot for your ideas. I really appreciate it!!

@jagabo: thx a lot for your support what I want is more like ur 2nd pic (Similar but with a very strong 2d noise reduction filter) maybe with the map a bit lighter...

@19nic2k4 : do you mean to shoot the candle and the map seperatly? problem is I dono too much about composite in after efect
can you tell me more about it plz? and when merging the 2 scenes, we still have the shadows from candle?

my scene will show the candle and the map, then later a hand will come to grasp the candle and turn it off violently... for the moment Im shooting in a dark room, with a 25w light bulb under the map the get it bright...

Thanks a lot in advance

[jagabo]

@jagabo: thx a lot for your support what I want is more like ur 2nd pic (Similar but with a very strong 2d noise reduction filter) maybe with the map a bit lighter...

I did that in VirtualDub. I used the Levels filter to bring the brightness down and the gamma up. Then a filter called 2D Cleaner (noise reducer) to smooth it out. Note that the last step will cause posterization artifacts, blur away small details, and may not look good in motion. But maybe that's the look you're going for. Most video editors have those type of filters.