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Dynamic Range of 5248 film from 1952


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How many stops of dynamic range did 5248 color camera negative film from the 1950's have?

There is a 4k clip of Bridge over the River Kwai on YouTube and it had some crushed shadows and blown-out highlights (though maybe not to that great of a degree): 

 

Edited by Jonathan Ruiz
Separating 2 sentences in post with "enter"
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From what I understand, prints have less DR than negatives due to the increase in contrast. I think? But, was this 4K scan done from the negative? If so, let's keep in mind that EXR was years away. EXR I think was an innovative stock which greatly expanded DR.

Black & white film had more DR than any colour stock for a long time, AFAIK.

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4 hours ago, Karim D. Ghantous said:

EXR I think was an innovative stock which greatly expanded DR.

When you say "greatly expanded", do you mean just fractions of a stop or less, or at least one or more entire stops?

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I doubt you can divine much from a Youtube video viewed on a (dare I guess uncalibrated?) computer monitor.

Not only do I think it was beautifully shot by Jack Hildyard, the Academy did too.

It's useful to a lighting cameraman (that's English for DP) to be able to analyse a shot in great detail, but it's as well to remember the feeling of a scene. Here, for example, the contrast between the beauty of the sunset and the abject horror of the POW's plight on the Burma Railway. Who said counterpoint was only for music.

They don't make 'em like that anymore. Lean hardly did again; after Kwai, he got slower that Kubrick.

Edited by Mark Dunn
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17 hours ago, Jonathan Ruiz said:

There is a 4k clip of Bridge over the River Kwai on YouTube and it had some crushed shadows and blown-out highlights

And you're judging that based on low-bit rate 8 bit YouTube clip? lol 

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16 minutes ago, Tyler Purcell said:

And you're judging that based on low-bit rate 8 bit YouTube clip? lol 

If there was more stops of DR than bits, it probably would of shown color banding or be encoded to a lower contrast but still show as much detail, not crush the shadows or blow out the highlights of the image (I think, IDK).

I think if you were concerned with that, it would probably be better to look at the 10 bit HDR 4k Blu Ray itself than that YouTube clip (but I think there might be an HDR option in said clip, I'm not sure, I haven't checked).

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There is no direct relationship between stops of DR and bits. But yes, 8-bit does not explain crushed shadows nor blown highlights. However, I guess what Tyler and Mark really meant is not truly about bits, but rather "who knows how that video has been processed ?". Internet is full of images with contrast pushed beyond seemliness.

By the way, if you are viewing this youtube video on a software-calibrated monitor on a Windows PC, calibration does not fully apply on videos: gamut is not compensated. Again, this does not explain crushed shadows and blown highlights, but colours may be off depending of the gamut of your monitor.

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Also keep in mind that many of those 50s Eastmancolor movies have been restored from b&w separations which sometimes have increased contrast. Or they’ve been restored from a faded color negative where adding contrast is the only way to fix the black levels.

It’s true that color negative back then did not have the wider dynamic range or latitude of later stocks and this was compounded by contrasty printing methods forcing cinematographers to use excessive amounts of fill light sometimes. But also the slow speed of the stocks encouraged some underexposure so shadow detail wasn’t always what the stock was capable of delivering. But even so, color negative back then was not that much more contrasty than it later became.

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  • 6 months later...
On 6/28/2022 at 8:33 AM, David Mullen ASC said:

But even so, color negative back then was not that much more contrasty than it later became.

Sorry for the late reply (6 months later), but I am not sure exactly what you mean by this sentence. Do you mean in the printing process during the 1950's for theatrical prints and making b&w seperations or future color camera negative stocks that came out in later years over the decades?

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I'm saying that color negative improved in terms of total dynamic range over the decades but it probably was not as dramatic an improvement as you'd think. Older movies had issues with deliberate underexposure due to the slow speed of the stocks, so not great shadow detail, which they compensated for by adding artificial lighting. A few cinematographers in the 1960s started playing with overexposure in day exteriors for a more "open" look, such as Conrad Hall. As the stocks doubled in speed each decades, there was also probably some improvement in dynamic range as well, particularly the jump from 25 ASA 5248 to 50 ASA 5250 it seems just by visual analysis.

You also have to factor in the occasional use of force-processing increasing contrast.

I'd also add that even today, jungles and forests in strong sunlight are the worst-case scenarios for contrast problems -- the difference between highlight and shadow can jump to several stops.

As I said, another issue is that many 1950's movies at best have been restored from b&w separations because the original negatives have been lost or have faded too much -- and often these b&w separations are on the higher contrast side.  Recently there have been some advances that restorer Robert Harris told me about, where since the blue record (yellow layer) fades the most, a movie can be restored by scanning both the faded original negative and the b&w separations and then using just the scan of the blue separation record in combination with the red and green information from the original negative. Or combining these scans in percentages.

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25 minutes ago, David Mullen ASC said:

I'm saying that color negative improved in terms of total dynamic range over the decades but it probably was not as dramatic an improvement as you'd think. Older movies had issues with deliberate underexposure due to the slow speed of the stocks, so not great shadow detail, which they compensated for by adding artificial lighting. A few cinematographers in the 1960s started playing with overexposure in day exteriors for a more "open" look, such as Conrad Hall. As the stocks doubled in speed each decades, there was also probably some improvement in dynamic range as well, particularly the jump from 25 ASA 5248 to 50 ASA 5250 it seems just by visual analysis.

If you could estimate how many stops of dynamic range 25 ASA 5248 had vs 100/125 ASA color negatives of the 70's vs 400 ASA color negatives of the 80's, how many stops would be for each? Even a rough estimate for one of those 3 would be good. I am just curious and would like a ballpark estimate compared to modern Vision3 500t stock (estimated to be around 14 stops give-or-take fractions of a stop). It's fine if you can't.

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I can't really, it would be a total guess of questionable value.

Vision-3 added a stop of dynamic range by the use of micro-grains, but the increase was only in the extreme overexposure region where the slow-speed of tiny grains allowed some information to be retained. But if I said that Vision-3 had 15-stops of dynamic range, I'm sure immediately someone would disagree. Which would mean I think Vision-2 had 14-stops. So I'd suspect that ever since 5254 100 ASA in 1968, color negative has been in the 13-to-14-stop range. So who knows, maybe the stocks of the 1950's (5248 25 ASA from 1952-59) was more like 11-to-12-stops -- I HAVE NO IDEA!

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We could estimate that by finding out how many layers those films had. Vision3 has three layers of each colour. Modern b&w film has two layers (I can't see why they can't have at least three?). Cheap 135 film like Kodak Color Plus maybe has two layers. I might have that info in a book somewhere.

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http://www2.optics.rochester.edu/workgroups/cml/opt307/spr04/jidong/
 

57D3D365-84CB-487D-8774-40F4A496744C.jpeg
 

But I don’t see how this tells you how many stops of dynamic range you end up with. Early slower-speed stock may have had fewer layers but the layers still had a random mix of grain sizes - I don’t think you could say that each additional layer adds a stop of dynamic range or anything that precise.

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2 hours ago, David Mullen ASC said:

I don’t think you could say that each additional layer adds a stop of dynamic range or anything that precise.

That's correct, but my point was that if we can draw some equivalents, and use some half-decent logic, we can work our way back. E.g. if A is like B, and C is like D, and we know the differences between A and D, we can sort of figure out the relationship between B and C.

Anyway, it's not going to be that simple, because we apparently have very little information about this. Ultra Max 400 and Vision3 500T have the same number of layers, more or less. From Making Kodak Film by Robert Shanebrook:

IMG_5134--.thumb.jpg.492d349dda5b678ceed2f6ca723dca86.jpg

 

 

Log curves might yield a clue, if we have them for any given stock:

https://www.filmshooterscollective.com/analog-film-photography-blog/a-practical-guide-to-using-film-characteristic-curves-12-25

 

Edited by Karim D. Ghantous
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