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Not understanding professional resolutions
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[Karen Jackson] “This is a bit of a deviation – does anyone know how you up-res from an Alexa camera (2.88k) to IMAX (which I believe is 7k)? And how much does it cost?”
What you’re asking about is “DMR”… which is IMAX’s Digital Media Remastering. Maybe that’s 7K, I don’t know… I’ve don’t know the exact specs on it.
A true IMAX film, is of course much much greater than 7K resolution because a real IMAX film is real film. I’m not sure of the “supposed equivalent resolution” because celluloid film isn’t really measured in terms of “K,” but some cinematographers have said by their best guesstimate that real 35mm film is probably in the equivalent of 20+K range as far as true resolution goes. Considering the IMAX frame is several times bigger than a 35mm frame (I haven’t done the surface-area math, but my pull-it-out-of-my-ear guess is that it is six or seven times bigger in area), then the resolution would be that same multiple x the resolution of 35mm film (if you are comparing the different formats with the same filmstock).
How much does it cost? Don’t know, but you can bet it’s not cheap… striking any real film print (which real DMR does) is never an inexpensive proposition. You’d have to ask the lab… which is probably only IMAX itself (I’m not sure if any other labs can do their proprietary upconversion).
T2
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Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com
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No need to guesstimate – the Arri study at the top of the thread measures the ideal 35mm exposure on a 200 ASA stock, saying that the smallest resolvable detail is .006mm large on the negative…
Super 16mm is 12.35mm x 7.42mm or 2058 x 1237 “points”
Super 35mm is 24.92mm x 18.67 or 4153 x 3112 “points”
65mm is 52.48mm x 23.01 mm or 8746 x 3835 “points”and Imax would be 69.95mm x 52.48mm (if the aspect ratio is 1.5 on the neg) so something like 13119 x 8746 “points”.
but since the grains move around, the digital grid should be twice as fine… so 20k is an overestimate for 35mm film, but there’s definitely a difference between 4K, 8K, and potentially 10K scans…
But my understanding is that digital IMAX projection is just two 2K projectors overlapping…so certainly not an equivalent to IMAX film projection…
KC
prehistoricdigital.com
hardworkingpixels.com -
Just stumbled on this thread so I’m a bit late to the topic…
I think what Kevin mentions is the key to what “looks good” on a movie screen. Film has the resolutions that film advocates usually quote…out-of-the-camera. After a couple stages of re-imaging (inter-negs, etc) to get through a traditional film edit, and then get to a distribution print, that film has gone through several generations of degradation.
The “organic” (if I may use an over-used term) look of film has a lot to do with the varying grain structure. Digital pixels can look a bit antiseptic because the “dots” are in a fixed grid, and film seems somehow more “natural” because of the somewhat random distribution of the grain structure from frame to frame.
That’s all great, but once you start to make those film copies, the next piece of stock has different random grain distribution…in digital, each pixel this generation correlates to a pixel (assuming you’re not scaling) in the next generation…in film, nothing says that film grains would line up the same way, and in fact they almost never do. The detail in film drops off through this process.
Panavision did a really informative lecture on MTF some time ago. In the later parts I think many may say they make a bit too much of an effort to push the Genesis over the RED, but the rest of the material is really very informative.
John Galt’s statement regarding distribution prints for theaters was rather telling…the target for MTF on distribution prints roughly equates the cycles per millimeter to 1000 TV lines if you can truly make this comparison “apples and somewhat different apples” which is also up for debate.
If you can get the dynamic range to perform adequately through the use of the right camera and informed post, HD resolution just shy of 2K should actually easily put up -at least- the resolution that 35mm film would in the theater.
Now…we haven’t even addressed the fact that contrast plays a lead role in human perception of “sharpness” and having really good contrast at a lower limiting resolution will always look “sharper” to a human viewer than very high resolution alone (and any of us who have ever aimed a camera at a resolution chart know that the highest resolution a camera/lens system is capable of is imaged at almost zero contrast).
Whether or not you feel the aesthetic is adequately comparable is an artistic viewpoint and will depend on who had influence on the production, the relative projection systems, and the viewer’s eye of course…
You can talk specs, but very few of us actually viscerally respond to resolution…
TimK,
Director, Consultant
Kolb Productions, -
All Tim’s observations are good and true… especially about film looking more “organic” due to the varying grain structure.
But keep in mind that generations of film on top of film on top of film (compounding the grain structure over and over again) is pretty much an “olden days” thing, when optical prints were being struck from a real cut internegative… which all stacked up to several generations of film by the time it got to the theatre screen.
Today, virtually all features use a DI, with the original scan coming directly from the original camera negative. It never sees film again until the final show prints are struck, which is more often done digitally, not optically. Therefore, if you are watching a feature in a theatre with a real 35mm film projector, you are usually seeing two generations of grain… the camera original, and the print that is being projected (and keeping in mind that projection prints are made on veeeery fine grain filmstock… much finer than the grain on the original camera stock). You would be seeing three generations if the final print was made optically instead of digitally, but that’s not usually the norm these days. If you are watching that same feature in a digital theatre, you’re only seeing one “layer” of grain… that from the original camera negative.
Again… the only thing that really matters is how good it looks to your eyeballs.
T2
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Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com
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Hi Todd,
I mentioned the film-throughout post theory because of your note in a post earlier in the thread:
Todd Terry: “The only way to get really really high resolution (actually much much higher than 4K) is with a project that is shot on film, edited on film, and projected on film.”
…no mention of a DI there.
🙂
I agree that a DI in place of multi-generation film post preserves resolution to the extent of the DI’s capability.
TimK,
Director, Consultant
Kolb Productions, -
Yep… that is true, the only way to get true film resolution is to keep it on film throughout… that was cited as a “maximum resolution example.”
But… whether fortunately or unfortunately, it just isn’t done that way anymore. The DI is definitely the norm, now. I think pretty much the last “bigshot” holdout was Thelma Schoonmaker (who cuts all of Martin Scorsese’s films, when she’s not busy polishing her Oscars). She always favored cutting real film with her hands and eschewed DIs with a passion… but has now come over to the “dark side” and cuts with DIs like pretty much everyone else doing features.
When the film world has lost Roger Deakins as a DP (who, after doing pickup shots with the Arri ALEXA, said True Grit was probably the last feature he would ever shoot on 35mm) and Schoonmaker as an editor… that’s one more kick in the pants for the all-celluloid purists.
Times, they do change….
T2
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Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com
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