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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 January 2nd, 2011, 04:02 PM   #16
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For the most amount of dynamic range, expose properly, which can mean underexposing certain situations in order to maintain highlights. Shooting "flat" is simply underexposing or overexposing digitally, not optically, and will introduce noise and reduce latitude. People preach "log" and "flat" because they have no idea how to operate a monitor; they assume that if they can't see it, it's not there, so they force it into the 6 bit range of the cheap LCD.
Sorry, but that's wrong. People aren't testing these setups based on a 6-bit LCD. The guys who do the Digital Praxis curves for example are testing these things thoroughly and properly. Such methods of gaining range have been used a long time in broadcast cameras. Often the camera in those circumstances is capable of recording up to 600% more contrast range than the standard gamma setup.

Let me put it very simply. People preach log and flat because of scientific measurement, not because of what they see on a 6-bit consumer monitor. Please look up the research and BBC settings of Alan Roberts, a man who was involved in HD since the 70's and has made this sort of setup and research his life's work. If you can disprove his research then I'm all ears...
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Old January 2nd, 2011, 11:08 PM   #17
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Originally Posted by Simon Wyndham View Post
Sorry, but that's wrong. People aren't testing these setups based on a 6-bit LCD. The guys who do the Digital Praxis curves for example are testing these things thoroughly and properly. Such methods of gaining range have been used a long time in broadcast cameras. Often the camera in those circumstances is capable of recording up to 600% more contrast range than the standard gamma setup.
It's different when you have a pro-grade 3chip imager with a 14-bit pipeline. In the context of consumer equipment though, all you're doing with these flat gamma curves is the equivalent of digital exposure compensation. But the primary objective of using a modified gamma curve is to change the way the operator exposes for a given scene.

Different curves are for different scene contrast conditions. For example, a curve with a 600% designation (which is not a linear scale, by the way) would be used for a high contrast scene with higher dynamic range than the imager can capture. Thus the curve will digitally gain up the shadows so that you can underexpose and still get proper skin tones without losing that shadow detail. You would use a different curve in a low contrast setting to reduce overall noise.

This is exactly what BBC, Allan Roberts, and [insert cinematographer name] will say.
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Old January 3rd, 2011, 03:53 AM   #18
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Thus the curve will digitally gain up the shadows so that you can underexpose and still get proper skin tones without losing that shadow detail.
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or example, a curve with a 600% designation (which is not a linear scale, by the way) would be used for a high contrast scene with higher dynamic range than the imager can capture.
I can't be bothered to go into all of this again. But I will say that you are misunderstanding it all and need to read the white papers. What Alans' settings do is access all the range that the chips are capable of achieving by looking at the knee points and knee slope. It is not, as you appear to think, about faking a gamma curve to merely give the impression of more range by gaining up the shadows.

I don't know how the settings work for the 7D and 5D etc, but as far as how this goes in most other cameras that's how the settings work.
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Old January 3rd, 2011, 07:18 PM   #19
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For event videography would you recommend using the neutral 0,0,0,0 setting inside the camera since scene changes can happen quickly - inside darkish tungsten lit sanctuary, to florescent lit hallway, to sunlight outside. Or maybe two settings - one for inside and one for sunshine.
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Old January 3rd, 2011, 08:42 PM   #20
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For event videography would you recommend using the neutral 0,0,0,0 setting inside the camera since scene changes can happen quickly - inside darkish tungsten lit sanctuary, to florescent lit hallway, to sunlight outside. Or maybe two settings - one for inside and one for sunshine.
Two settings: one for high contrast, one for low contrast
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Old January 3rd, 2011, 08:45 PM   #21
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What Alans' settings do is access all the range that the chips are capable of achieving by looking at the knee points and knee slope.
It is not possible to increase the dynamic range of an imager with a gamma curve. You can, however, decrease the dynamic range by using the wrong gamma curve for the given scene. The curve out of the box is not tailored for dynamic range, but instead for low noise and visually pleasing contrast.

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I don't know how the settings work for the 7D and 5D etc
I do.
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