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Sensor motion cadence. Why are some cameras so good at it?

Asker Mammadov

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I apologize in advance if this isn't the correct sub-forum for this question, but it didn't seem like it fit into any of the other ones so I put it here. Feel free to change it if it doesn't.

Lately, I've been watching all kinds of footage from different camera brands ranging from the most budget friendly film-making cameras all the way up to the premium stuff. And while there is no doubt that we're living in the golden age of cameras (in terms of being accessible to new-comers), at one point I came across a comment where someone mentioned the term "motion cadence" and how high level cameras have that little something that stands out against the budget versions. I never really knew the word for it until he said that term, and I have noticed that it really does add a pleasing motion to the image quality (this is all assuming 24fps 180 shutter, of course). What is the reason for this discrepancy between manufacturers? The only thing I could think of was perhaps the type of shutter being used in digital cameras but that's about it. Thanks

Edited by Asker Mammadov
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I've never heard this term before - by that I assume you mean an element of jitter/discrepancy of sampling time between each frame with the ideology that film doesn't sample each frame at a perfect 1/50th (25 frames) of a second down to a nanosecond interval. So digital cameras should try and represent this? Or that each camera at x frame rate at 180 degree shutters have different sampling times? 

In terms of discrepancy between manufacturers, most sensors are all designed a little differently in terms of physical circuitry between model and manufacturer. Different sensors will have different paths for read-out and most 'HDR' cameras that boast higher latitude typically have some level of multiple or decision amplification.

I read a Sony white paper on Gain Adaptive Column amplifiers that store linear analogue signals in temporary memory for a faster digital 'shutter' that exceeds the clock speed of the comparator sending signals to different column amplifiers. The point being, different signal paths may alter the read-out time from the physical photo site and overall sensor which would marginally impact sampling time.

Generally a digital shutter is the combination of power follower and reset transistors (output and reset) in a 3T APS CMOS photo site. Some cameras do have additional circuitry per-photo site however, as each element you add reduces the total space for photodiode/'s it's from my understanding reasonably similar from sensor to sensor. I would imagine the differentiation of sampling time would be due to different analogue circuitry prior and during sampling... but I don't think this would really impact motion unless an incredibly inferior scheme is used.

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