Arri Alexa and Mysterium-X...

[Julio Quintana]

Jim,
With all the confusion surrounding "native sensitivity", maybe we need a new definition in the digital age. Most people think of ISO in terms of the exposure level needed to see into the shadows. But since that is such a huge range now, MAYBE IT MAKES MORE SENSE FOR ISO TO REFLECT THE EXPOSURE AT WHICH THE SENSOR CLIPS. That is the only number that is fixed and not subjective. Just a thought.

[Michael Bravin]

First - no such thing as a "real asa" for these cameras ... I can guarantee that the raw linear light sensor data is way too dark lit ISO800 to be of any use at all.

Graeme

With all due respect Graeme, this is without your having seen ALEXA, or having seen the sensor technology, capture methodology, raw data etc, in my view from this side a "guarantee" at this point is shaky at best. In due time on schedule as promised we will present ALEXA to the general public and we can then have a healthy and productive discussion about what we all see and can measure. Of course I believe we have the goods, but its really up to our customers and professional DP's to decide what we are offering, don't ya think?

[Patrick Tresch]

Jim,
MAYBE IT MAKES MORE SENSE FOR ISO TO REFLECT THE EXPOSURE AT WHICH THE SENSOR CLIPS.

Imagine you have a sensor with 40 iso (clipping point), this doesnt tell you anything about you mid gray value wich is what we call "a visible image"...

I should elaborate more... but kids just came in...

Pat

[Julio Quintana]

Imagine you have a sensor with 40 iso (clipping point), this doesnt tell you anything about you mid gray value wich is what we call "a visible image"...

Pat

That's my point. Right now 320 ISO doesn't tell us anything particularly useful about the mid gray value of the M-X sensor since the range of acceptable mid gray exposures is so large. When people hear 1600 ISO, they think "Holy crap. I'll have to ND everything", because they don't understand that the sensor's "clipping ISO" is 320.

[Graeme Nattress]

With all due respect Graeme, this is without your having seen ALEXA, or having seen the sensor technology, capture methodology, raw data etc, in my view from this side a "guarantee" at this point is shaky at best. In due time on schedule as promised we will present ALEXA to the general public and we can then have a healthy and productive discussion about what we all see and can measure. Of course I believe we have the goods, but its really up to our customers and professional DP's to decide what we are offering, don't ya think?

No, I think you should read what I wrote very very carefully. And then go look at the ISO definition of ISO for raw data. Basically, it says there is no real definition for raw, and just go with what the manufacturer recommends for a good image. I specifically mentioned a linear light image which we all know that without a proper development curve will look too dark. That's how linear light looks and works. The point being that it is raw data + curve that develops the image and we call the ISO based on where that development curve puts mid grey.

http://en.wikipedia.org/wiki/Film_sp...exposure_index good reading on what a mess "ISO" is.

Graeme

[C.H.Haskell]

In just weeks of being on the market, MX is already head to head with ARRI's latest offering. Enough said. RED is in good company and when I see good competition, i see progress. (film has another 30 years at least, my2¢) :)

[Graeme Nattress]

That's my point. Right now 320 ISO doesn't tell us anything particularly useful about the mid gray value of the M-X sensor since the range of acceptable mid gray exposures is so large. When people hear 1600 ISO, they think "Holy crap. I'll have to ND everything", because they don't understand that the sensor's "clipping ISO" is 320.

What is a "clipping ISO" and how does a cinematographer use that with a light meter?

Graeme

[Patrick Tresch]

Even film's "rating" is just a suggestion by Kodak or Fuji. After designing a stock, and testing it, they settle on a speed that produces the "best" image, in their opinion.

Harry and Greame summed it up IMHO...

Dop has to learn and to know how to handle the camera output, wich is wunderfull, as it is a project based choice. Now you can always go as Kodak/Fuji/RED tell you to treat your media.

Pat

[Mike Gross]

With all due respect Graeme, this is without your having seen ALEXA, or having seen the sensor technology, capture methodology, raw data etc, in my view from this side a "guarantee" at this point is shaky at best. In due time on schedule as promised we will present ALEXA to the general public and we can then have a healthy and productive discussion about what we all see and can measure. Of course I believe we have the goods, but its really up to our customers and professional DP's to decide what we are offering, don't ya think?

I get graeme's point as "Linear light" is always dark regardless of camera because of it's very nature. With the dual gain announced in Alexa, outputting an image that's not linear light is similar to taking a linear light image and transforming it into something else.

[Graeme Nattress]

I get graeme's point as "Linear light" is always dark regardless of camera because of it's very nature. With the dual gain announced in Alexa, outputting an image that's not linear light is similar to taking a linear light image and transforming it into something else.

Although, remembering that you must transform to linear light before matrix to get colorimetry to work.

Graeme