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Canon EOS Crop Sensor for HD
APS-C sensor cameras including the 80D, 70D, 7D Mk. II, 7D, EOS M and Rebel models for HD video recording.


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Old December 29th, 2010, 01:47 PM   #1
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Is noise/grain unavoidable with the 7D?

Hello!
I recently recorded a scene with the 7D. No fast movements occur. I had the time to light rather carefully. My camera settings during shooting:

ISO: 100.
Sharpness and contrast set to lowest.
Saturation set to 2 below standard.

My aim was to avoid noise as much as possible. The scene contained areas of deep shadow, from darkest dark and up.

I converted the mov file to the Cineform format using the trial version of Cineforms HDlink,

Resulting movie is still grainy and noisy, albeit not so much.

I realize I was na´ve, but I actually thought that setting the ISO to lowest and lighting carefully would eliminate grain/noise issues. Now I conclude eliminating noise in deep shadow areas is not possible.

Could someone please confirm/disagree with my conclusion?

I just want to know the limitations I'm working under, so I don't waste time trying for the impossible.

Regards,
Nikolaj
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Old December 29th, 2010, 02:20 PM   #2
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Check how sharpness and contrast are set on your monitor. Many monitors have these set pretty high "out of the box" and any extra emphasis on either or any oversharping will cause artifacts that look like digital noise where there really is none.

A year ago I got a new Dell with a 22" Dell widescreen monitor. I never thought to check sharpness, brightness, and contrast on the monitor itself but attempted to use the software approach to set it up. I had no end of video looking way too "noisy" on that one while my other workstation monitor worked well with both video and Photoshop.

Plenty of sharpness and detail but very little noise. I used the buttons on the monitor and found sharpness and contrast up around 90%-95% with brightness a bit high too. Once I pulled everything down to about midpoint things looked a lot better.
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Old December 29th, 2010, 03:15 PM   #3
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I did as you suggested; it seems to have some small effect. Thanks a lot for the suggestions.
But the problem remains I think. Hopefully the attached clip will give you an idea of the problem.

I'll upload it when it works... encountering problem with uploading my movie sample.
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Old December 29th, 2010, 11:12 PM   #4
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Digital video and photo don't handle dark areas of an image very well. Black and darker shades of gray will tend to be noisy and/or pixelated.

Beyond that, you should stick with the "good" ISO values of 160, 320, 640 etc. as has been discussed elsewhere in this forum. ISO 100 is actually slightly noisier than 160.
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Old December 30th, 2010, 06:48 PM   #5
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I find the 7D noisy and don't use it for stills because of that. I think if you have a scene without dark shadows it will record it fine, it's just part of the limitations a small sensor with 18 megapixels. The canon 5D2 is much better with noise.
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Old January 4th, 2011, 02:35 PM   #6
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Quote:
Originally Posted by Nikolaj Marquez von Hage View Post
ISO: 100.
contrast set to lowest.
If you use only 6 or 7 stops of dynamic range like most people, you'll find the 7D has very little shadow noise, because the deep shadows are crushed. But when you increase the dynamic range beyond the default through the contrast setting, you can see a lot of read noise contaminating the image.

Quote:
Originally Posted by Nikolaj Marquez von Hage View Post
My aim was to avoid noise as much as possible.
If that was your aim, then you should *decrease* dynamic range by increasing the contrast setting.

Quote:
Originally Posted by Nikolaj Marquez von Hage View Post
Could someone please confirm/disagree with my conclusion?
You are correct. The 7D has very poor dynamic range because of read noise at low ISO. Another factor to keep in mind is color temperature. ISO 100 in 2800K Tungsten has the same noise level as ISO 400 in 5600K light.

Quote:
Originally Posted by Erik Andersen View Post
ISO 100 is actually slightly noisier than 160.
ISO 160 has less deep-shadow noise, but ISO 100 has less mid-tone noise. I recommend ISO 160 because the deep-shadow noise is usually more of a problem. But if you know that you will be crushing those shadows anyway, then ISO 100 will let you have less noise in the midtones. (Another annoying factor is that each setting has slightly different highlight headroom.)

Quote:
Originally Posted by Norman Pogson View Post
I find the 7D noisy and don't use it for stills because of that.
What's sad is that most of the deep shadow noise (i.e. poor dyamic range) is caused by simple fixed pattern noise. With a very basic calibration tool, the raw converter would be able to remove the noise losslessly and improve the dynamic range by several stops. Unfortunately, neither Canon nor any of the other raw converters have bothered added this feature (except for the alpha version of RawTherapee).
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Old January 5th, 2011, 07:05 AM   #7
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Using the multiples of ISO 160 does seem to have less noise, I don't use ISO 100 as a minimum but 160 instead.
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