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C200 Noise in 8-bit mp4? Possible sensor issue?


Ben Kleeg
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Hi, 

I recently picked up a used C200. The first thing I noticed was that the blue antireflective coating on the EVF was mostly scratched off -- this isn't a huge issue for me as I rarely use it, so I've started to shoot some 8bit mp4 footage; however, I'm noticing a lot of noise on my images especially in lowlight.  

I’m attaching some stills to show what I’m talking about:

 

This is a C-Log 3 image with the canon C-Log 3 to Rec.709 LUT applied. ISO 800. 10WtydS.jpg

 

For reference, here's the same image with no LUT. The noise is still visible, just not as noticeably. 

Pd17E28.jpg

 

Another graded image at ISO 800.  The grain seems to present as chunks of red/green -- notice in the lower left:R0fxvzv.jpg

And ungraded:

LimU46F.jpg

 

Now, I read that Log profiles are not meant for low-contrast low light settings, and if shooting 8bit then the WIDE DR profile is more suitable (can anyone tell me if I'm wrong?). 

Here's a super low light shot on the WIDE DR profile at ISO 8000.  Obviously, at such high ISO's grain is expected, but I'm just wondering if this looks normal to everyone for the settings? 

VwiYZvN.jpg

 

Finally, I've captured some less grainy shots:  Here's an image shot on the WIDE DR profile, which I then over exposed by a stop, while pulling the ISO down to 160: 

kHqw1hd.jpg

The result is much better, however, I'm concerned because zoomed in, the green/red grain pattern is STILL present, just less accentuated than on the harsher grades for the C-Log 3 images I shot:

Here's a zoomed image from the above shot -- is this level of noise and compression normal for the 8bit MP4 codec?

WVvDpes.jpg

 

To sum up: I previously used a C100 mark I, which I would routinely shoot under-exposed to preserve highlights and then lift in the grade -- it was certainly noisy in the shadows, but to my eye it was a less intrusive monochromatic grain that felt pleasing.  In contrast, when I underexpose and pull up the image with the C200, the grain seems to present in harsh blocks of red/green. 

So: I'm hoping someone more knowledgeable than myself can tell me if I have something wrong with my camera (Is it possible that sun damage from the lack of Anti-reflective coating on the EVF has addled the sensor?), or if the C200 just doesn't handle underexposing very well and whether I'm also just grading the 8bit files too hard.

Thanks!

Ben

 

 

 

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Although you are at ISO 800 you have massive underexposure going on in those images for C-LOG, which means the dark areas where the noise is are more like ISO 12,800 if you push them in post.

So the solution is... Stay at ISO 800 but light the scene, or use a faster lens.

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Have you done any grading other than applying a LUT? I was underwhelmed by the .mp4 files from the C200 but didn't find them quite this noisy, I found raw lite noisier. How did you expose these shots? The log files do look dark.

Try black balancing and see if it helps a bit. 

I had the same experience with the C100 having more noise (and a stop less highlight detail) but nicer noise texture, at least with an external recorder. I found the C100 noisy when I exposed properly, more so than the C200, but the look was nicer when it was. Made me focus more on aesthetics and less on specs (or even lab tests) but with a camera that has gobs of dynamic range as the C200 has, it's easy to expose incorrectly, too. And then the noise reveals itself in post.

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15 minutes ago, HockeyFan12 said:

Have you done any grading other than applying a LUT? I was underwhelmed by the .mp4 files from the C200 but didn't find them quite this noisy, I found raw lite noisier. How did you expose these shots? The log files do look dark.

Try black balancing and see if it helps a bit. 

I had the same experience with the C100 having more noise (and a stop less highlight detail) but nicer noise texture, at least with an external recorder. I found the C100 noisy when I exposed properly, more so than the C200, but the look was nicer when it was. Made me focus more on aesthetics and less on specs (or even lab tests) but with a camera that has gobs of dynamic range as the C200 has, it's easy to expose incorrectly, too. And then the noise reveals itself in post.

Hi, the first image is just a LUT, exposure around f4.  The second image (the banister) is no LUT, and instead a curves adjustment -- that was also f4.  The other stills (the Wide DR exterior and the low ISO interior), have no grading applied to them, and are f2.8 

If this is just the result of my poor exposures, than that's great -- I just want to be certain of that.  Is there some kind of objective test I can run to ascertain if there's something wrong with the camera in terms of noise levels?  Would getting in touch with Canon help?

 

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Hard to tell without getting access to the files but it looks underexposed from what I can see. I also noticed from personal experience that the 34% IRE exposure on 18% grey (value recommended by Canon for C-log and C-log 2) always looks underexposed to me and I tend to expose at around 40% in general.

Black balance could also be an option, it doesn't hurt to try.

Log curves are made to preserve DR and for advanced grading, not for low light situation.

Also, I believe that C-log 3 was originally introduced on the C300 mk2 for the 10 bits mode so it might not be the best option for the C200 in 8 bits. Have you tried shooting in C-log 1? You should get less DR but cleaner shadows as this curve was designed for 8 bits.
It's normal to get less noise in WDR mode, technically this is not a log curve but an in between profile with BT.709 shadows and highlight protection from LOG. I think the recommended ISO for WDR is 400 but ISO160 will give you the best result on the shadows.
 

Finally, you should cover the EVF with the provided cap or strong sun exposition could damage the sensor.

 

 

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4 minutes ago, User said:

Interesting. Is this exclusive to the C200, or does it also apply to a C100Mk2 as well?

Not sure about the C100mk2 but lower ISO should give you less noise in general (at the expense of DR).
Also, optimal ISO for C-log 1 is 400.

So:
ISO 400 for C-log 1 and WDR
ISO 800 for C-log 3
I'm not sure about the ISO for C-log 2 but I would say it's 800 (to be confirmed)

 

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Just now, OliKMIA said:

 

Not sure about the C100mk2 but lower ISO should give you less noise in general (at the expense of DR).
Also, optimal ISO for C-log 1 is 400.

So:
ISO 400 for C-log 1 and WDR
ISO 800 for C-log 3
I'm not sure about the ISO for C-log 2 but I would say it's 800 (to be confirmed)

 

Thank you. I asked because I always shot WDR at ISO800 on the C100MKII even on bright days as I had the idea that this was the native ISO and the best way to get the most out of WDR. Was this wrong?

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8 minutes ago, User said:

Thank you. I asked because I always shot WDR at ISO800 on the C100MKII even on bright days as I had the idea that this was the native ISO and the best way to get the most out of WDR. Was this wrong?

C100 and C200 are pretty different in my experience. 

Not sure what to make of it, but the C100 has +5.3 stops of highlight dynamic range at base (850 ISO). C200 has +6.3 at base (800 ISO). So for the C200 maybe the best way to get an image closer to the C100 is shooting 400 ISO where the highlights will be similar.

How are you metering? Since most of us are just metering by eye the ISO setting feels kind of irrelevant relative to how we expose, or at least can only be discussed in that context.

I found the cameras to be completely different. Totally different looks, totally different ergonomics, totally different workflows.

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1 hour ago, User said:

Thank you. I asked because I always shot WDR at ISO800 on the C100MKII even on bright days as I had the idea that this was the native ISO and the best way to get the most out of WDR. Was this wrong?

I'm talking about the C200 here and I'm not sure about the C100mk1. Just check the user manual and official canon resources. The recommended "native" ISO values are there. Get the info from the source, not just a bunch of nobodies on forums (including me!).

In one of the Canon papers they also show the distribution of DR in highlights and shadows based on the ISO. Basically, my understanding is that lower than native ISO will give you less noise but also less DR.

More than the difference between ISO 800 and 400 in log 2, I don't shoot in log low light. I stick to WDR for that (which again, is not a log curve). Log 1 is also acceptable as it was designed for 8 bits capture. Usually, low light situation doesn't come with the need for great DR capture. Just my 2 cents.
 

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3 hours ago, OliKMIA said:

Hard to tell without getting access to the files but it looks underexposed from what I can see. I also noticed from personal experience that the 34% IRE exposure on 18% grey (value recommended by Canon for C-log and C-log 2) always looks underexposed to me and I tend to expose at around 40% in general.

Black balance could also be an option, it doesn't hurt to try.

Log curves are made to preserve DR and for advanced grading, not for low light situation.

Also, I believe that C-log 3 was originally introduced on the C300 mk2 for the 10 bits mode so it might not be the best option for the C200 in 8 bits. Have you tried shooting in C-log 1? You should get less DR but cleaner shadows as this curve was designed for 8 bits.
It's normal to get less noise in WDR mode, technically this is not a log curve but an in between profile with BT.709 shadows and highlight protection from LOG. I think the recommended ISO for WDR is 400 but ISO160 will give you the best result on the shadows.
 

Finally, you should cover the EVF with the provided cap or strong sun exposition could damage the sensor.

 

 

Thanks very much to you and everyone for the informative responses!   One question: The EVF is a digital viewfinder, yes?  Because I keep on getting conflicting info on whether letting sunlight into it would damage the actual camera sensor, or simply damage the display on the EVF -- i.e. is the EVF connected somehow to the camera's internal components, or is it just taking a digital signal from the sensor and displaying that like the monitor?

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5 hours ago, HockeyFan12 said:

How are you metering? Since most of us are just metering by eye the ISO setting feels kind of irrelevant relative to how we expose, or at least can only be discussed in that context.

Thank you for the insight.
I'm in a long hall edit with the material now. So looking back, I'd run with 850 ISO until I run out of light and then pump it up as needed. Shot the first night (of a 3 month period) in Clog and realized something was way off. Lensed everything after in WDR. Simple solution for a run and gun in a difficult situation.
 

3 hours ago, OliKMIA said:

I'm talking about the C200 here and I'm not sure about the C100mk1. Just check the user manual and official canon resources. The recommended "native" ISO values are there. Get the info from the source, not just a bunch of nobodies on forums (including me!).

- Absolutely. Guilty as charged. Love the self deprecating levity.
 

3 hours ago, OliKMIA said:

In one of the Canon papers they also show the distribution of DR in highlights and shadows based on the ISO. Basically, my understanding is that lower than native ISO will give you less noise but also less DR.

- Yes, this was my understanding as well. And I imagined pulling down the shadows to hide any buzz. But if there had been more time and support it would have been good to really tune the camera to the situations and light as necessary.
 

3 hours ago, OliKMIA said:

More than the difference between ISO 800 and 400 in log 2, I don't shoot in log low light. I stick to WDR for that (which again, is not a log curve). Log 1 is also acceptable as it was designed for 8 bits capture. Usually, low light situation doesn't come with the need for great DR capture. Just my 2 cents.

- Exactly. And I like WDR. For what I do it seems the best of Clog, without limitations.

Thanks for the refresh and insight folks... I'll remember the bring the white paper (so I have something to wipe myself off on in that infernal heat of whatever lays ahead)... onward.

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14 hours ago, OliKMIA said:

Hard to tell without getting access to the files but it looks underexposed from what I can see. I also noticed from personal experience that the 34% IRE exposure on 18% grey (value recommended by Canon for C-log and C-log 2) always looks underexposed to me and I tend to expose at around 40% in general.

Ok, so I did some digging in my canon resources.

First I need to correct the IRE values I gave you earlier. Here is the exposure for 18% grey recommended by Canon, these values are indicated in this great paper for the C300mk2 but I saw similar values for the C200:

C-log 1 = 34% IRE
C-log 2 = 39% IRE
C-log 3 = 34% IRE

I think C-log 2 is only available by default when shooting Canon raw with the C200 but there is no C-log 2 for 8 bits recording on the C200 which makes sense considering how "aggressive" c-log 2 is. Personally, I have no shame to revert to non log curve on some cameras because shooting with aggressive log curve on many 8 bits cameras is a non-sense (eg. S-log 3 on sony, D-log on earlier 60mpbs 4k DJI drone, etc.). I see too many people selecting C-log no matter what because it's "Pro" or "better"... This is plain stupidity if you can't nail the exposure (eg. uncontrolled environment outside) or don't have advanced grading skills.

Don't forget that you can apply LUT directly to the LCD screen if you prefer to expose "visually" as judging exposure on the screen in Log can be tricky and it might be the reason why you underexposed in the first place. Indeed, on the screen, Log footage looks brighter which is why you should stick to a reference (grey card and IRE value, X value for certain type of skin-tone, or ballpark estimate on the EV indicator).

Also, as far as the colors and look goes, check the "Color Matrix" in the Custom picture/HDR menu (where you set the gamma). Here you must understand how it works with the C200. There are basically 2 options to select the gamma curve:

#1. Select one of the presets (Off, BT.709 (WDR), C-log, C-log 3), here the gamma curve and associated color matrix are grey out and they are locked inside the preset with these settings (screenshots from the C200 user manual)

cp.thumb.jpg.b0ab854f6db4927b7c56124762718768.jpg

#2. Leave preset OFF, then the gamma and color matrix are not grey out and you can choose the combination you want. Notice from the table above how C-log 3 uses the neutral color matrix whereas C-log 1 uses the "Cinema EOS Original"  which is a color profile designed to match colors across the EOS camera board (eg. C100, C300, etc.). You may want to play with that if you are not satisfied with the color and overall rendering.

Finally, you can also tune the colors in the "other settings" option in the CP/HDR menu.

Cheers


 

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23 hours ago, Ben Kleeg said:

 One question: The EVF is a digital viewfinder, yes?  Because I keep on getting conflicting info on whether letting sunlight into it would damage the actual camera sensor, or simply damage the display on the EVF -- i.e. is the EVF connected somehow to the camera's internal components, or is it just taking a digital signal from the sensor and displaying that like the monitor?

My bad, I wanted to say display, not sensor! Obviously there is no optical link between the EVF display and the sensor so sun frying your EVF is not going to impact your sensor.

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