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July 2nd, 2009, 08:25 AM | #1 |
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Grainy/noisy video
If anyone could advise me on this subject I would be most grateful. Basically, I've just finished shooting a drama video with a brand new Canon XL-H1A camera and much of the footage has a very grainy look (very noisy), particularly with the interior low light shots. I set up the camera before shooting to record at 25fps (the F2 position) in HD with the cine 2 gamma curve custom preset mode selected. I was using Sony HDV tapes. At no time did I use gain and the white balance was set for the appropriate conditions (daylight and tungsten). We were using 350 watt mini redheads which gave more than enough light but we set the aperture to darken the scenes for atmosphere; perhaps this look should have been left until post production? Although the footage is sharp and correctly exposed (that all looks nice) the "grain" is akin to early 16mm Eastman film (not the new Vision stocks). My intention WAS to achieve the film look but not like this! Have I done something wrong? Perhaps I should have left the gamma settings alone? Can someone suggest a good camera set up for future films that I make, bearing in mind that I'd still like to achieve the film look but with HD quality? I was expecting a really nice HD look with the film I've just shot but I'm not sure if the footage would stand being shown on a widescreen HD television or monitor in its edited form. Finally is there a remedy to tone down the noise in FCP 5.4?
Many thanks Simon |
July 2nd, 2009, 12:54 PM | #2 |
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I recently was in the field and had a similar issue.
At first, when the sun was still below the horizon, I turned on auto gain to test what the camera could do in low light. After 30 minutes, when I moved the knob back to -3db it did NOT reset back to -3db. The HDSDI signal I was monitoring on a 7" Nebtek showed a nice CLEAN image. However that is NOT was recorded to tape. I had a loon come in close in the most glorious morning light ever. On playback once home days later, that shot was GRAINY AS HELL. I lost some of the best footage I have ever shot due to this issue (or my stupid *%^@ up). For those who think the latter, that I simply screwed up, the funny thing is the lens (100-400mm 35mm EF w/ EOS and adapter) had PLENTY of light. In fact, I was using 'screw on' ND filters so I could open the iris up. So, what this means is that even though there was plenty of light, once auto expose was engaged, the camera boosted gain to like +18db and LOCKED on +18db. Very strange. And again, the image on the monitor was GREAT, certainly NOT the grainy crap I found on playback. I think that when the camera was powered off later is when auto gain finally disengaged. And that footage looks KILLER. Sorry to hear you had a similar issue - ARGH! Jacques
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Jacques Mersereau University of Michigan-Video Studio Manager |
July 2nd, 2009, 01:25 PM | #3 |
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Hello Jacques!
Sorry also to learn of your similar experiences! I would still be interested to hear if anyone has any practical advice about this phenomenon. I'm sure it's just me setting up the camera via the menu incorrectly. I haven't viewed the footage on an HD monitor or TV yet just on my Macbook Pro (not the latest model). Advice anyone? Cheers Simon |
July 2nd, 2009, 06:55 PM | #4 |
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I hate to bare the bad news to you guys, but the XLH1 has a very high noise floor. Particularly with any gain above 0. And particularly in tungsten.
Welcome to the world of 1/3" chips. Even Panasonic's brand spankin' new HPX300 has very similar noise characteristics as the XLH1. If you can, always expose for the shadows and NOT the highlights. I'd rather a few highlights clip than an entire show riddled with noise. That was our philosophy on our feature film "The Blackout". However, my DP lit the show to a higher stop and then we graded it back down. Noise is less prevalent. But it's still there. Also, try crush the blacks in post a couple points. That should help mask some of the noise in the shadows. |
July 2nd, 2009, 08:47 PM | #5 | |
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July 3rd, 2009, 01:29 AM | #6 |
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That is what puzzles me - thanks for your replies both of you - the gain was set at 0 throughout the shoot and certainly not on auto gain. One thing is clear though; the noise is less obvious in the scenes with more light and more obvious in the darker scenes. Perhaps the camera has a gain override facility if it thinks a scene is too dark? Does this mean that it is not possible to shoot darker, more atmospheric scenes, in case the noise returns? If so this is going to be difficult for our company as we shoot films that need plenty of low light conditions.
Thanks again Simon |
July 3rd, 2009, 08:56 AM | #7 |
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So you are saying that you for sure have the auto gain switch in the "off" position and gain at 0db? if so can you post a frame grab or try -3db setting and see if it help.
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July 6th, 2009, 07:39 AM | #8 |
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I'm with Robert. Make sure that you are giving enough exposure to the shadows. It can help if you use a spot meter to read the shadows and the highlights so you know what you are trying to cover. The H1 doesn't have a large dynamic range so you may have to compromise and loose some detail somewhere. Just know where and make sure you are giving the overall scene enough light. If you have to brighten in post much at all, you will see noise.
You can also try Neat Video to remove noise. Neat Video - best noise reduction for digital video It is slow to process, but does a good job of removing noise. |
July 6th, 2009, 08:15 AM | #9 | |
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HDV to be as clean as the HDSDI mind you, but it shouldn't be super grainy in comparison. |
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July 6th, 2009, 08:22 AM | #10 |
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- what type of monitor are you using?
- how does the image read on a waveform monitor - are blacks at 0? - you set aperture to "darken the scenes" - what aperture were you shooting at? - when poss stay away from anything above 6.2, and never go above 8 |
July 6th, 2009, 03:42 PM | #11 |
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It's hard to tell what the problem is without seeing the resultant footage. To some people any noise at all is considered unacceptable. To some noise is an acceptable side-effect of small imager cameras and are used to it. I guess what I'm saying is that it's a simple matter of degree. How much is considered "normal" and what is considered a "problem".
I have noticed recently that a lot of guys who came from the ENG/EFP 2/3" world who are now shooting XLH1/HVX/HPX300/EX1 are regularly complaining about noise issues with these cameras as if the camera itself has a problem that needs fixing. Nope. That's the image these cameras camera. Sorry folks. Also, I've discovered that you really cannot "see into the shadows" with 1/3 cameras. It seems like there's been this falsehood that HD can always shoot low-light. Which is wrong and truly does not apply to anything other than ultra-high end cameras like the Viper and the F23. 1/3" HD cameras really need to be lit exactly like 16mm (in other words, you have to light, light, light). No free lunch here. |
July 6th, 2009, 04:33 PM | #12 |
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Many thanks everyone for your very helpful replies which I shall now look into; I'll report back once I've shot some new footage under similar conditions.
All the best Simon |
October 15th, 2009, 05:16 PM | #13 |
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I too get stuck with the grain/noise issue. I am little better off now days thanks to understanding what the camera does under various auto settings.
During the read of this thread, I think there may be some confusion. The auto gain setting and the auto "big knob" camera setting (which enforces auto gain setting no matter what) are not same - even though the result is the same as far as lack of user gain setting control is concerned. . So when one user complains that they did not have their gain set to auto, that really doesn't matter unless you also have the "big knob" camera setting to be off the auto setting too. Otherwise you are going to get grain/noise on many shots because auto gain setting is enforced when either of these two knobs are set to auto. I did find one solution in POST using Neat Video noise reduction plug-in. I use the Adobe Premiere version, but there are other supported platforms too. Best regards, Ron LectureMaker.com |
October 19th, 2009, 06:04 AM | #14 |
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NEAT VIDEO is definitely your solution. I recently bought it and it is excellent.
Harry |
October 21st, 2009, 08:12 AM | #15 |
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I'm not familer with the XL HA but I do use the Canon XHA1. If you are in an easy or auto mode, your camera will control the gain settings on its own regardless of what you have the controls set to. If your not already, try shooting in manual mode and see if you have the same problem. Low light levels frequently mean more grain. Make sure that your letting enough light in. Although I have not used it, I've heard good things about "Neat Video" which is a plug in that removes grain.
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