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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Arri Alexa and Mysterium-X...

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

Graeme
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Not sure. I guess as a DP, I would want to know that the sensor deals with highlights like a 500 ISO film stock, but I can get an acceptable mid gray exposure at 2000 ISO, or whatever. So maybe from here on out digital sensors should be given two values, such as 500/2000 ISO.
 
When we tested the MX camera, the default setting was 800 but the red tech said it's really a flexible iso range.

Would 800 be native for MX? After testing I found 1000 to be a good starting point but actually liked 2000 too.
 
M Most said:
Michael, my guess is that you either don't know or haven't talked to very many "top DP's and directors," because if you have, you would find that the vast majority are very interested in testing anything new and seeing what they can accomplish with it. If they find advantages for a particular project, they are usually the first to suggest using new cameras, lenses, or anything else. They would also give you some very real and very good reasons why they would want to shoot film, and equally good reasons why they would want to shoot digital on certain projects. It has very little to do with the issues you're suggesting, and everything to do with producing the best and most appropriate imagery for the particular story being told in the most production friendly manner possible given the particular production circumstances and likely distribution paths.
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I respectfully disagree. Whenever someone makes an observation about motivation, especially if there is a negative connotation, there will never be agreement from those about whom the observation is being made. I wasn't talking about what Top DP's or Directors "say" when asked but about what I think is the subconscious internal objection keeps them shooting film. It's one thing to be willing to test new technology. It's quite another to admit you no longer need the old technology that helped to set you apart from the masses because it required so much knowledge and experience to master. I also never said, all, just said many. There really are very, very few reasons to shoot film anymore and the situations where film is used instead of digital where film justified are far outweighed by the situations where film is not justified and is actually rather a major hindrance to the process and a big waste of money.

I've seen this exact same scenario in 6 industries now personally over my career. First it was in the desktop publishing and photo retouching industry (Quark vs. Paste Up and Photoshop VS. Paintbox), then in the printing industry (Offset VS. Indigo), then in the Photography Business (Film VS. Digital) then in the Web Development Industry (ASP/JAVA vs. PHP) then in the database industry (Oracle vs. MySQL) and now I've watched it happen in the film industry. It's just not finished yet, but the course is the same. People just need to let go earlier. Life would be so much happier.

Sincerely,

-michael zaletel

Sincerely,

-michael zaletel
 
Michael Bravin said:
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?
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Given that I'm trying to learn here so I can make effective camera choice decisions, what is the definition of ISO you're using for Alexa? The article says that the Alexa chip itself is rated at ISO800 - how is that rating achieved? How as a camera user can I use the ISO800 rating information effectively?

Albert
 
Julio Quintana said:
Not sure. I guess as a DP, I would want to know that the sensor deals with highlights like a 500 ISO film stock, but I can get an acceptable mid gray exposure at 2000 ISO, or whatever. So maybe from here on out digital sensors should be given two values, such as 500/2000 ISO.
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Isn't that getting back to Jim's concept of an "acceptable range" though?

Graeme
 
Graeme Nattress said:
Isn't that getting back to Jim's concept of an "acceptable range" though?

Graeme
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Yes, I see what you're saying. But if you tell me that the RED has an acceptable ISO between 320 and 2000, that doesn't tell me anything about highlight clipping.
 
Albert Armes said:
Given that I'm trying to learn here so I can make effective camera choice decisions, what is the definition of ISO you're using for Alexa? The article says that the Alexa chip itself is rated at ISO800 - how is that rating achieved? How as a camera user can I use the ISO800 rating information effectively?

Albert
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Albert
Dr Hans Kiening of ARRI Munich who is a well regarded image analysis specialist (and a really nice guy), has devised a test methodology to determine dynamic range that is available to everyone. The specially designed test chart and analysis software determines "usable" image at highlight clip and noise floor by allowing for measurement of modulation (picture information) at both ends. You can evaluate ISO by rating the camera, performing the test, and evaluating the result with the included software. More info is found here http://www.arri.de/camera/35_mm_digital/dynamic_range_test_charts.html

IMHO Its time we all played on the same playing field once again. Camera manufacturers now have a methodology that is common across all capture mediums, from 1/3"CCD/CMOS to 65mm film.
 
Graeme Nattress said:
What is a "clipping ISO" and how does a cinematographer use that with a light meter?

Graeme
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Guessing here but if you develop with a 2.2 Gamma 50% gray would have equal DnR above and below.

That's my "good enough" definition for ISO.

A clipping ISO would in my books be something like RED without FLUT at 640ISO in which case if you simply applied a 2.2 gamma to the raw linear image and put middle gray at 640 without anything beyond 2.2 gamma you would need to apply gain in which case you would clip whites.
 
Jannard said:
We have believed, since IBC last year, that these two platforms would be the ones standing for the future. We are very proud to be in such good company.
Jim
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I think it's amazing that the FIRST camera RED built - with a sensor upgrade - is right alongside the THE industry leading camera manufacturer's next-gen camera technology.
 
Chris Clogg said:
Seems odd that they wouldn't just shoot it all in Red perhaps? Maybe there's something they left out... Or maybe it was a while ago before they could get Red. I don't know... but when I was reading I immediately thought "RED!!!"
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I believe this all happened around 2007 in which case RED still hadn't proven itself or even necessarily been released yet.

The Dalsa Evolution was just that, an evolution of the Origin. It was the same sensor as the Origin I believe so they knew what they were going to get out of it.
 
I totally understand RedOne's 320 ISO and the protection of the highlight by one stop. I always go 320 and don't look at the RAW in the camera, except under tungsten.

But since the MX is the same sensibility, at ISO 800, were are losing a lot of tone value by underexposing ? 12 bit = 4096 tone value, the first stop got 2048 tone value that will, certainly, not be use because the MX sensor will be under more that 2 stops under his native sensibility.

Didn't test the MX, but seem to have a better noise floor as we all know, but do we have more details in the shadow ?

thanks.
 
Michael Bravin said:
Albert
Dr Hans Kiening of ARRI Munich who is a well regarded image analysis specialist (and a really nice guy), has devised a test methodology to determine dynamic range that is available to everyone. The specially designed test chart and analysis software determines "usable" image at highlight clip and noise floor by allowing for measurement of modulation (picture information) at both ends. You can evaluate ISO by rating the camera, performing the test, and evaluating the result with the included software. More info is found here http://www.arri.de/camera/35_mm_digital/dynamic_range_test_charts.html

IMHO Its time we all played on the same playing field once again. Camera manufacturers now have a methodology that is common across all capture mediums, from 1/3"CCD/CMOS to 65mm film.
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Reading that link though, it's meaning of ISO is referenced back to a film stock. How is that to help us when we know that as mentioned earlier in the thread that the ISO rating of film stock is whatever the manufacturer thought best.

Albert
 
Etienne Caron said:
But since the MX is the same sensibility, at ISO 800, were are losing a lot of tone value by underexposing ? 12 bit = 4096 tone value, the first stop got 2048 tone value that will, certainly, not be use because the MX sensor will be under more that 2 stops under his native sensibility.
thanks.
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This is the kind of technical stuff that most DP's don't want to think about. If I am shooting with the M-X, this could be my theoretical process:

1. After testing myself, I prefer the look when I rate mid gray at 1000 ISO.
2. If I know the sensor really clips at "X" ISO, I know that I have "Y" stops of headroom.

So when I'm on set, I'm only thinking about two numbers: 1000 and "X". With that information I can shoot like film. Without "X", I would be inclined to think that my highlights will clip like a 1000 ISO film stock, or a 1000 ISO DSLR.

I'm just throwing out ideas.
 
Julio, so what you're really asking is "if ISO800 puts mid grey where we want it, at what ISO would that mid grey be at clip, or in other words, how many stops above mid grey do I have?"

Graeme
 
Albert Armes said:
Reading that link though, it's meaning of ISO is referenced back to a film stock. How is that to help us when we know that as mentioned earlier in the thread that the ISO rating of film stock is whatever the manufacturer thought best.

Albert
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Albert
Doing the test is how you determine the result. On page 3 of the download it explains the test. You do not need to have film to make this test and determine performance characteristics at different ISO ratings, you get a nice chart that shows you the results to simply evaluate and compare.
 
Michael, I'm reading through the link you gave above and I'm puzzled - "To determine the sensitivity of your camera you can simply rate it relative to the film scan." So ISO is relative to film or not? The download explicitly says "Sensitivity is relative to 500 ASA Kodak Vision3 film stock"

Graeme
 
Graeme Nattress said:
Julio, so what you're really asking is "if ISO800 puts mid grey where we want it, at what ISO would that mid grey be at clip, or in other words, how many stops above mid grey do I have?"

Graeme
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Exactly. I think DP's need an easy way to calculate this whether they rate the camera at 320 or 2000, and the only way I can see is to add another number, something that corresponds with the absolute point at which the sensor clips.
 
David Mullen ASC said:
And there are a lot of directors who like film -- I seriously doubt "Transformers 3" will be shot digitally, for example.
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I've been wondering this for a while... so with Red and digital formats, you can record to 12 bit RAW, or whatever else, to get more ability to grade in post. Now with big movie productions shooting film, and then digitally scanning it, do they get the same level of manipulation that shooting digital provides? E.g. can they scan the negatives to get more than just 8 bit jpegs?
 
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