Canon Talks Global Shutter and High Dynamic Range

[Don Haines]

I'd also expect to see lots of cheap, virtually unsalable older models - including my own 5D3.

I'm sure my 5D3 will be thoroughly worn out by then! Best purchase I ever made.

I too am very happy with my 5D3.

It's just that 92dB is massively massively huge dynamic range. It would permanently wipe the smile off the Sony fan-bois.
Such a dynamic range would be difficult if not impossible to print without significant compression of that range.
Much like digital sequencers, synthesizers, and recorders did away with the need to be skillful in playing music and capturing the sound, so too will a 92dB DR camera do away with the need to consider the amount of light on different parts of the subject.

You are cute to think that others will just sit back lol. Canon is miles behind DR wise. Let them play the catch up game first lol

93 dB would be 16 stops..... Yes, it is better, but it is not revolutionary better.

More like 30 stops - if one stop is a doubling of light.

If it was a 10log function, then it would be 31 stops, but this is power and for that we use a 20log function and we end up with almost 16 stops.....

 

[Ozarker]

what is a global shutter? how does it differ from other types of shutters? In other words, why is a global shutter important?

Rather than a long dissertation, why not google the term. There are a ton of articles on the internet.

Simply put, it means the shutter will function no matter what continent one is standing on. 8)

 

[IglooEater]

92 db. Could someone translate that to stops for me? Is that something like 30 stops, or am I waaayy off here?

Here is the Wikipedia definition, and, as you can see, its as clear as mud. However, 90 DB is clearly not the same as the electrical power definition.

Video and digital imaging

In connection with video and digital image sensors, decibels generally represent ratios of video voltages or digitized light levels, using 20 log of the ratio, even when the represented optical power is directly proportional to the voltage or level, not to its square, as in a CCD imager where response voltage is linear in intensity.[35] Thus, a camera signal-to-noise ratio or dynamic range of 40 dB represents a power ratio of 100:1 between signal power and noise power, not 10,000:1.[36] Sometimes the 20 log ratio definition is applied to electron counts or photon counts directly, which are proportional to intensity without the need to consider whether the voltage response is linear.[37]

However, as mentioned above, the 10 log intensity convention prevails more generally in physical optics, including fiber optics, so the terminology can become murky between the conventions of digital photographic technology and physics. Most commonly, quantities called "dynamic range" or "signal-to-noise" (of the camera) would be specified in 20 log dB, but in related contexts (e.g. attenuation, gain, intensifier SNR, or rejection ratio) the term should be interpreted cautiously, as confusion of the two units can result in very large misunderstandings of the value.

Photographers typically use an alternative base-2 log unit, the stop, to describe light intensity ratios or dynamic range.

Thanks Mt Spokane! I guess they don't mention what scale they're using, so we'd have to make a wild guess?

 

[3kramd5]

what is a global shutter? how does it differ from other types of shutters? In other words, why is a global shutter important?

Rather than a long dissertation, why not google the term. There are a ton of articles on the internet.

Simply put, it means the shutter will function no matter what continent one is standing on. 8)

Hah. Zing

 

[unfocused]

what is a global shutter? how does it differ from other types of shutters? In other words, why is a global shutter important?

Rather than a long dissertation, why not google the term. There are a ton of articles on the internet.

Simply put, it means the shutter will function no matter what continent one is standing on. 8)

Let's not be rude. By definition, if you are on this forum, your time is not that valuable that you can't provide a bit of guidance. I don't understand it, or really care, but there is actually a decent description in the Canon announcement. It has to do with avoiding distortion in fast moving objects, where the object may be in a different spot when the curtain of a focal plane shutter closes, than it was when the curtain opened, thus causing distortion.

As I understand it, it's more of a problem for film than stills.

 

[RGF]

what is a global shutter? how does it differ from other types of shutters? In other words, why is a global shutter important?

Rather than a long dissertation, why not google the term. There are a ton of articles on the internet.

Simply put, it means the shutter will function no matter what continent one is standing on. 8)

Does that mean the camera has its own passport?

 

[KeithBreazeal]

My 20 year Navy career was anti-submarine warfare. I worked in R&D in the mid-70's and we developed our new aircraft based sonar system that basically did the same thing. It sampled the buoy data and stored every frequency scan for a period of time, could tell noise from actual frequencies, delete the noise, and then render clean sound. It was so perfect that sonar operators listening with headsets actually wanted some white noise added.
This is a brain/audio thing that occurred and it was determined that the brain's audio processing needed a constant input.
The CRT displays showed the perfect clean signals and were used most of the time.
I had always wondered how long it would take before this concept could be applied to processing image data.
I could envision this technology used in telescopes.

 

[Don Haines]

what is a global shutter? how does it differ from other types of shutters? In other words, why is a global shutter important?

Rather than a long dissertation, why not google the term. There are a ton of articles on the internet.

Simply put, it means the shutter will function no matter what continent one is standing on. 8)

Let's not be rude. By definition, if you are on this forum, your time is not that valuable that you can't provide a bit of guidance. I don't understand it, or really care, but there is actually a decent description in the Canon announcement. It has to do with avoiding distortion in fast moving objects, where the object may be in a different spot when the curtain of a focal plane shutter closes, than it was when the curtain opened, thus causing distortion.

As I understand it, it's more of a problem for film than stills.

Let me give it a try......

A "normal shutter" reads a line at a time across the sensor, from the top to the bottom. If there is motion (panning) the subject of the panning will be ok, but there will be horizontal motion between scan lines and things in the background that are supposed to be vertical are now angled.

This happens both in still and video. A global shutter would "lock" all the lines in the sensor at the same time, so when they were read, there would be no relative motion between lines....

 

[Jack Douglas]

I'd also expect to see lots of cheap, virtually unsalable older models - including my own 5D3.

I'm sure my 5D3 will be thoroughly worn out by then! Best purchase I ever made.

I too am very happy with my 5D3.

It's just that 92dB is massively massively huge dynamic range. It would permanently wipe the smile off the Sony fan-bois.
Such a dynamic range would be difficult if not impossible to print without significant compression of that range.
Much like digital sequencers, synthesizers, and recorders did away with the need to be skillful in playing music and capturing the sound, so too will a 92dB DR camera do away with the need to consider the amount of light on different parts of the subject.

You are cute to think that others will just sit back lol. Canon is miles behind DR wise. Let them play the catch up game first lol

93 dB would be 16 stops..... Yes, it is better, but it is not revolutionary better.

More like 30 stops - if one stop is a doubling of light.

If it was a 10log function, then it would be 31 stops, but this is power and for that we use a 20log function and we end up with almost 16 stops.....

Hmm, as a worn out EE me thinks power is 10log, V and I being 20. Not that it matters.

Jack