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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 :)

Mysterium-X dynamic range...

David Mullen ASC said:
You may find this interesting, though not of much practical value for filmmaking:
http://www.clarkvision.com/imagedetail/eye-resolution.html

This may be more interesting:
http://www.luminous-landscape.com/columns/eye-camera.shtml

That Wikipedia article that Cail posted a link to is interesting:
The retina has a static contrast ratio of around 100:1 (about 6 1/2 f-stops). As soon as the eye moves (saccades) it re-adjusts its exposure both chemically and geometrically by adjusting the iris which regulates the size of the pupil. Initial dark adaptation takes place in approximately four seconds of profound, uninterrupted darkness; full adaptation through adjustments in retinal chemistry (the Purkinje effect) are mostly complete in thirty minutes. Hence, a dynamic contrast ratio of about 1,000,000:1 (about 20 f-stops) is possible.
Click to expand...

Makes me wonder how close 32 bits-per-pixel displays (in the future that is.. currently we only see on 8bpp displays as far as I know) will be able to recreate real/life lighting. No matter how many f-stops our cameras can capture... the displays need to be able to display that range too, otherwise it's just compressed/stylized into 8 bit color like that HDR effect photographers do...

-cc
 
David Mullen ASC said:
That Wikipedia article that Cail posted a link to is interesting: The retina has a static contrast ratio of around 100:1 (about 6 1/2 f-stops). As soon as the eye moves (saccades) it re-adjusts its exposure both chemically and geometrically by adjusting the iris which regulates the size of the pupil. Initial dark adaptation takes place in approximately four seconds of profound, uninterrupted darkness; full adaptation through adjustments in retinal chemistry (the Purkinje effect) are mostly complete in thirty minutes. Hence, a dynamic contrast ratio of about 1,000,000:1 (about 20 f-stops) is possible.
Click to expand...

Pardon me for saying, but I LOVE this sort of stuff. So what is the focal length, say, of the human eye? It's said that "normal" focal range is 50-55mm, yes? Is this then equal to the distance, say, between the lens of the human eye and its retina? Again, interesting to know that the human eye has 20 f-stops dynamic range. Wonder what the acuity or resolving power is of an eagle's eye compared to that of human. Ok, I digress. If anyone is interested, two books I recommend on visual issues are:
Eye and Brain: The Psychology of Seeing by Richard Gregory and Visual Intelligence: How We Create What We See by Donald Hoffman. :-)
 
Jannard said:
Maybe I should have put one of these at the end?

:-)

Jim
Click to expand...

I am so confused. I can already see B+W picture of me at Red Studios saying in bold letters "do NOT sell/rent to this guy". I've never had the pleasure of meeting you so I don't know your humor. I might be misreading you, you might be misreading me, in the end: I don't want to get blacklisted Jim.

I'll post my next question out of Recon to be safe.
 
Roberto Lequeux said:
I am so confused. I can already see B+W picture of me at Red Studios saying in bold letters "do NOT sell/rent to this guy!". I've never had the pleasure of meeting you so I don't know your humor. I might be misreading you, you might be misreading me, in the end: I don't want to get blacklisted Jim.

I'll post my next question out of Recon to be safe.
Click to expand...

I have the feeling he's just messing with you. Just a feeling. ALthough I am in no way speaking on Mr. Jannard's behalf here.
 
@Joseph:
According to the link above, the eye has a 22.3mm f3.2 lens, and according to wiki, the retina has a diameter of about 22mm, and there is no clear border.
270px-AcuityHumanEye.svg.png


Back on topic:

I often thought about how to improve DR for a given sensor size. Of course, you could reduce read noise - and there is a steady improvement in this regard. Those 13+ stops and low noise of M-X sound really great, and I look forward to play with some raw files. But this is only possible as long as the unavoidable photon shot noise does not become dominant. Then you could increase the fill rate and quantum efficiency by e.g using back side illumination and/or layerd/monochrome (beam splitter) sensors, but the gain is too small considering that all those technologies currently have major "gotchas".
The only other idea I can think of is to ND parts of the sensor area. You would lose some shadow range obviosly but in turn gain more highlight headroom.
Interesting times...

Regards, Matt
 
Jannard said:
Blah, blah, blah... the question is whether or not you can DO something with this sensor. Beating the numbers to death is making me numb. Jim
Click to expand...

I agree! I have seen the MX footage projected in 4k and I have touched the camera. IT LOOKS AMAZING! I am stoked for the 13 stops! I am sure the 12bit numbers matter in some way, but the images look amazing.

Bottom line I would prefer 13 stops over 9 no matter what the bit rate.
 
Roberto Lequeux said:
I see. Thanks. What is the instantaneous dynamic range of human sight?
Click to expand...

I've been curious about this for a while, so I did some tests. I shot a sequence of pictures looking out the window from the far side of the room. It's a bright and sunny day, so there's about as harsh a backlight as you can get -- a pretty common photographic problem.

I slowed the shutter speed till the dark maroon afghan on the couch -- the darkest thing in the scene that I could still see detail in -- read as bright white (blown out) and then sped it up by a stop till the snow on the neighboring roof out the window read as total black. This was with my fairly inexpensive canon digital rebel.

It took 18 stops to go through the whole range. For the maroon afghan to go from black to white took 9 stops, and for the snow outside to go from black to white, also 9 stops. I'm guessing it could be inferred from that that my camera has 9 stops of dynamic range.

So then I picked the shot where I thought the outside scene with the snowy roof was exposed closest to what I saw in real life (while I'm looking at the whole scene, mind you, couch included), and the shot where I thought the couch and walls were exposed closest to what I saw in real life, and found that there was 4 stops exposure difference between the two.

Do you think that means the human eye has about 13 stops of inclusive (that is, my eye's iris at a fixed aperture) dynamic range? I feel like my logic might have a whole somewhere, but it seems like that's what it means.
 
David Rasberry said:
With the newer builds and software I think it is more like 10-1/2 to 11 stops for Mysterium.
Click to expand...

Jim,
Since your recent tests have found M-X to be 13 stops, I would like very much to know your rating of Mysterium so we can have a common basis for comparison.

Thanks,
 
Brad Webb said:
Never underestimate the dynamic range of a smiley. :thumbsup:
Click to expand...


Yes, yes....I agree, and, this relates to what I often call
"The Theory of Emotional Relativity".

:emote_happyhappy:
 
Julio Quintana said:
Jim,
Since your recent tests have found M-X to be 13 stops, I would like very much to know your rating of Mysterium so we can have a common basis for comparison.

Thanks,
Click to expand...

The Red pototype 'Fankie' was 11.3 stops, there have been several major break thoughs since then.

Stephen
 
There are several ways to measure DR (hence the propensity for a variety of results from different manufacturers). Measured S/N from the sensor. Measured output through the system using a variety of methods, including what Hollywood DI did last week. We have ordered the Arri DR test equipment and when we get that, plus finish calibration... we will do all of the tests and publish all of the results.

Jim
 
Rob Ruffo said:
I for one feel that learning and reading and understanding is also important - as important as hands-on experience. You need both.
Click to expand...

Great camera gods once say: "Must take knowledge with you where ever you go, but if you don't go.. you won't know."

I'm very eager to see what all M-X is going to look like in practice! Having the numbers is a great place to start... but it's the "view" all the talented people around here are going to capture that has my current interest. (Call that a schmooze if you wish.. it's more like a pat on the back)

:)

~s
 
Jannard said:
There are several ways to measure DR (hence the propensity for a variety of results from different manufacturers). Measured S/N from the sensor. Measured output through the system using a variety of methods, including what Hollywood DI did last week. We have ordered the Arri DR test equipment and when we get that, plus finish calibration... we will do all of the tests and publish all of the results.

Jim
Click to expand...

Hi Jim,

Could you let us have the results for both the M & MX sensor.

Thanks Stephen
 
Chris Parker said:
using the same calibration and testing, it will be useful to know how the old sensor compares to the new sensor. cool stuff....
Click to expand...

Better color rendition, I would imagine, will also affect dynamic range. If colors are more subtly defined, then there will be more detail in the darks when under-exposed at the extreme end of a range (chroma detail is still detail, even if luma values are more or less the same for neighboring pixels) . This has borne true as I have upgraded digital stills cams over the past few years.
 
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