Canon t2i noisy video. Why?

T

The Irish TRex

Well-known member
Hi!
So I just used a buddy's t2i for a video shoot and had the 50mm 1.8 lens on. It was an indoor shoot (fairly dimly lit but nothing crazy...meaning a room during the day but with the shades shut and several lights on) with the camera set at 1080p24, shutter: 50, ISO 400, 1.8 aperture. The person in the shot was about 8 feet away and had a black shirt on. His black shirt was a noisy mess when I pulled the card out and checked the footage on my laptop. I was shocked. Dropping it to ISO 200 was too dark but I figured that 400 wouldn't be that bad with noise in the shadows. It's not my camera so I don't know really what other settings to tweak but is there something else causing this??? Or is this normal for this camera/setup?

The weirdest part is that I've seen "low light tests" on youtube and vimeo of this camera (some at even ISO 800) with none of the noise that I'm seeing in the shadows on the camera I used.

BTW, in post, I crushed the blacks which helped somewhat but is that really what I have to do every time to get rid of 60-70% of the noise?

(I'd post a frame grab but I no longer have the footage.)
 
Hard to judge if it is normal or not without some footage for reference. I think some people claim that shooting using a Technicolor CineStyle picture profile increases the signal to noise ratio in the darks (but blacks are set to ~16, so you might want to crush them back down a bit in post).

Also, shooting at ISO 160, or 320 should give better performance than ISO 100 or 200. Hell, I think even ISO 640 might have less noise than ISO 200. Here is a great video of an ISO test: https://vimeo.com/23082874

Lastly, you can use Neat Video to decrease noise in post.

Oh, and also, add light when you can! I realize that is not practical in many situations. I personally prefer ugly noise to crushed blacks. Neither is desirable, but I just can't stand crushed blacks.
 
The proble is not what ISO you use, but how much light the lens is picking up. If that black shirt is heavily underexposed, it will show noise even at ISO 100. If it is overexposed, it will be clean even at 1600.

So, you shot ISO 400. Looking at the waveform: what brightness values does the black shirt fall on?

And finally: apart from crushing the shadows, you can also apply noise reduction in post: Neat Video if you can afford it, MB Denoiser II if you want a cheaper, simpler option.
 
Ive noticed this same thing at low ISO, but only when using picture styles which attempt to vastly improve dynamic range, such as Cinestyle or Flaat_11. The 550/600/60 just flat out suck when underexposed, the noise floor is so high. I have to always use neat video unless Ive shot something in broad daylight or a very well lit environment. I dont know if the 650D is any better with its newer processor...
 
That sounds like classic underexposure- were you looking at the exposure meter for his shirt as you shot? You shouldn't see noise if that's pegged in the middle. Still 400ASA for an indoor shoot with minimal lighting sounds way too low, even with that relatively speedy lens. That you were wide open tells me you probably needed more light to compensate.

-Noah
 
Here are some clips from something I was messing around with. I think it was iso 800 @ F2.0 on my 60D?? I was using the Flaat_11p picture style. There was a bright streetlight not too far away, and light from the inside of the house spilling out. Definitely dark though. I used the Neatvideo Noise Reduction program through VirtualDub, it works wonders as you can see.

This one is straight out of the camera
unedited.jpg

This one is after Neatvideo Noise Reduction
denoised.jpg

This one is after a basic color/curves adjustment in Davinci Resolve Lite
denoised_colored.jpg

This is with some grain added through Virtualdub (probably could find a grain plugin for Resolve...)
denoised_colored_grain.jpg

Before.... (JPEG compression killed the noise when i resized this)
unedited_full.jpg

After....
denoised_colored_grain_full.jpg

Its very possible to get good footage from a dark noisy scene!
 
Thank you all for your help!

No doubt more light could have been used but I was in a tricky situation shooting a well know actress for a "cold reading" for an audition with minimal time for setup. The guy was the stand in before she arrived. When she arrived, she had a light shirt on so it didn't look too bad. I didn't use the waveform because, well I feel like even after all these year of shooting on various cameras, I've never taken the time to learn that. But without getting into that, I read about the 160/320/640 ISO being better than 200/400/800 but how do you get the camera to go to those numbers? From what I remember with the camera it went straight from 200 to 400 to 800, etc.

Neat Video seems to be awesome and is really reasonably priced. I should probably pick it up but I guess I was just surprised because like I said, seeing other lowlight tests online other people's blacks seem to be noise free at comparable ISO's/aperture/shutter settings.
 
As Samuel and Joe have both mentioned, the issue is less to do with ISO and more to do with portions of the frame that are underexposed, or close to the noise floor. That is the tricky thing when shooting with DSLRS. You want to expose to the right as far as you can without blowing out the highlights (not always possible of course). The only way to get intermediate ISOs of 160,320,640 etc on a T2i/550D is to install Magic Lantern. I thoroughly recommend this, not only for the ISOs, but for many other things too: Kelvin, Peaking, Zebras, Histogram, Intervalometer, Cropmarks.... and so on.
David.
 
swopiv said:
As Samuel and Joe have both mentioned, the issue is less to do with ISO and more to do with portions of the frame that are underexposed, or close to the noise floor. That is the tricky thing when shooting with DSLRS. You want to expose to the right as far as you can without blowing out the highlights (not always possible of course).
Click to expand...

So do non-dslr's not have this issue when dealing with underexposed portions of shots? I usually don't work with DSLRs so this issue is new to me.
 
First of all, don't use cinestyle or flaat_11. Use flaat_10 or neutral with -4 settings (contrast sharpness)
 
The Irish TRex said:
So do non-dslr's not have this issue when dealing with underexposed portions of shots? I usually don't work with DSLRs so this issue is new to me.
Click to expand...

I should have been more specific. The issue is not exactly with DSLRs, rather with the H264 compression. The reason that the blacks are uglier than lighter areas of the frame are because they have a much lower signal to noise ratio, so a lot of what is encoded is noise, which can clump together in blocks. Older tech like DV still had problems with noise in the dark areas, but it showed up as graininess rather than blocking.

"The camera sensor has lower signal-to-noise ratio in the blacks and higher signal-to-noise ratio in the whites. This is because noise is more or less evenly distributed on the sensor but there are less photons hitting the sensor in the darker pixels."

This quote was taken from the excellent shutterangle.com: http://www.shutterangle.com/2012/canon-picture-styles-shooting-flat-or-not/

Read all his articles. Twice. Good info.

So yeah, expose to the right and light things properly. :)
 
maarek said:
First of all, don't use cinestyle or flaat_11. Use flaat_10 or neutral with -4 settings (contrast sharpness)
Click to expand...

I don't think this is the best advice. Flaat_11 and cinestyle can give excellent results when properly lit and with some noise reduction even on the old canon 18 mp sensors.
 
Here is another example, using the 60D with Sigma 30mm @ F2.0 and 1/47 shutter in magic lantern. Flaat_11p picture style.
This is obviously not production quality, but then again you would never shoot in this (nonexistent) lighting. I can upload the actual videos to youtub if anyone wants to see them in motion.

When i uploaded the images form my PC, the compression ruined them, and when I tried to insert the pics from the photobucket URL, it said the files were too large. So here are some links. :Drogar-Thinking(DBG

Original:
http://i181.photobucket.com/albums/x166/joeyisfunny/Original_zpsb1b3c93e.png

Denoised, exposure adjusted, and colored:
http://i181.photobucket.com/albums/x166/joeyisfunny/Cleaned_Colored_zps80a5e8bd.png
 
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JoeThePro said:
I don't think this is the best advice.
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Yes it is. Cinestyle does nothing good. If you want a milky look just raise the blacks afterwards. Way better than compressing them later.

Cinestyle does A) raises the blacks from 0 to 16. This loses dynamic range. B) Takes away the nice highlight rolloff, creating clipping whites in the process. C) Increases noise in the blacks and when you pull those blacks down in post, the noise is there in plain sight. D) Doesn't really help in grading anyway and E) makes it more difficult to assess exposure while shooting.
 
JoeThePro said:
I don't think this is the best advice. Flaat_11 and cinestyle can give excellent results when properly lit and with some noise reduction even on the old canon 18 mp sensors.
Click to expand...
I would concur with maarek on this one. Cinestyle in particular robs peter to pay paul. In the end of the day you only get so much info down the pipe with these 4:2:0, 8 bit camera's. They show horrible noise in the shadows with a more neutral profile and annoying noise in the mid tones with the very flat profiles.

My solution has been to expose to the right a bit with Flaat10p. The highlights clip no matter what anyway, so let unimportant highlights go and crush the shadows back in post to prevent noise. I've found that I get much better results this way and much more usable data in the overexposed highlights than I thought possible.

Cheers,
Pete
 
Shooting 16-255 actually helps with noise since you are clipping the noisiest part of the picture. Maybe you see more noise because of boosted gamma. You can't have high DR AND have pretty colors since the limiting factor is working with 8 bit. If you want low noise, pick a style the allocates bits towards the darks. It might help, but you are still screwed by h264 compression and sensor heat/size. If you want nice tones use the lowest DR profile you can. You can read more about Cinestyle signal/noise here:
https://www.fxphd.com/blog/squeezing-the-most-out-of-a-5d-mk-ii-or-alexa-signal/
http://eventfilm.at/blog/en/video-noise/

But, cinestyle clips stuff, and has crappy looking color. You will often get more banding and spend more time editing than if you had shot with a stock canon profile. It's all about your personal experience, and picking the right profile for the job.
 
FilmBrute said:
Shooting 16-255 actually helps with noise since you are clipping the noisiest part of the picture.
Click to expand...

There is no clipping, the blacks are just raised up to 16. Once you pull it back, the noise is there but even worse.

Cinestyle uses 16-255 because it was meant to match cineon filmscanners. Now it matches. The thing is... filmscanners use 16-bit dpx files usually so there is leeway in bringing the darks up a abit.
 
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