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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 :)

Resolution of 35mm film and 70mm IMAX film?

Film negative can be scanned at the same resolution for RGB individually, but I don't think that means that each color layer in the negative resolves information equally. The magenta dye layer in the middle containing the green information is generally sharper and finer-grained, hence why green screen is preferred often for generating keys, the yellow dye layer on top is a bit grainier if the stock is tungsten-balanced, particularly for 500T stock, and the cyan layer containing red information is on the bottom, which is one reason why scenes lit in red lighting tend to look soft.

I think that 35mm film is no longer the gold standard when it comes to resolution... and resolution is not the primary reason why people still love 35mm film. I don't think it is soft by any means either, it's just that I think an Alexa in 3.4K raw mode is competitive with 35mm film when it comes to resolution.
 
M Most said:
I won't bother to point out that this paper was written over 16 years ago, was intended to measure performance of an all-film origination through projection chain, and based on film stocks that haven't been manufactured since around 2006.

Wait a minute - I think I just did...... :sarcasm:
Click to expand...

Through the whole chain - starting with the negative, which they measured. Has film negative stock for acquisition doubled in resolution since 2006?

Graeme
 
Wasn’t that measurement for a 1.85 chart? Does 2100 l/ph mean 2100 pixels vertical? Then wouldn’t the horizontal be more like 3.8K? If that paper was measuring the chain to release print, then the area that was recorded for measuring would be more like 21mm x 11.3mm, so that’s 2100 l/ph for 11.3mm, not 18mm.
 
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I don't think the resolution, measured in l/ph, would change with the measured area. It's not really an area dependent metric, or at least logically it shouldn't be.
 
Yes David - I found in the article where they fill 11.33mm for the vertical height. So that's 2100l/ph where the height is 11.33, making horizontal resolution on the neg higher than I said earlier at 2100*1.85=> 3,885. Thanks for spotting my error there!!

Mike - l/ph does depend on the size of film measured. l/mm would be a size independent measure.

Graeme
 
Thanks for pointing that out. I was indeed thinking l/mm.
 
I find l/ph very confusing myself. I like nice unambiguous linear resolution and find it's so easy to make mistakes (as I did above) in converting between them.

Graeme
 
That's a great article Robert and is exactly on point in regards of diving into film particles and their spacing. This seems to be put together a touch before Vision 3 hit the market, but it's pretty much spot on in many ways.

The additional info is the relationship to film speed and increased particle spacing, which results in increased sensitivity with the effect of more apparent and visible film grain as well as a very slightly lower resolving image. Lower ASA, slower speed, have a tighter particle pattern and less grain is visible. Subtle variation in Dynamic Range actually occurs across various speeds as well.

With modern stocks, particularly 50D exposed under receiving a daylight source (or optically produced daylight from tungsten) you'll net the cleanest possible image. And interestingly enough, the intermediate stock used in laser recorders that isn't ideal at all for normal photography, is actually far less sensitive. Which is why it's used for dups or filmouts.

Just conversationally circling back around to digital cinema, much of this "feels familiar" as when we increase our ISO sensitivity we also see more image noise/texture. To reiterate what I wrote earlier, ideally you want to meet or exceed 4K resolution for Super 35mm 4-perf, error on higher resolution capture for a higher quality image upon downsampling. As for Dynamic Range, ideally your system captures somewhere between 13-15 stops and hopefully exceeds that.

For the current RED Line-up in terms of filming at the pure format size of Super 35mm 3-perf Full Aperture, in order of format resolving power:
- Helium 8K S35 = 7K
- Monstro 8K VV = 5K
- Dragon-X 5K S35 = 5K
- Gemini 5K S35 = 4.5K

All of RED's current sensor technology line-up meets or exceeds motion picture film's measured resolution on a per format basis. These days in terms of color and Total Captured Dynamic Range we are also on the side of greater than side of things and industry-wide we've been well ahead on sensitivity for a long while. On a personal level, this is all part of what brought me over to this ecosystem as my main tool for capture. I won't rehash that as I've written and spoken about it all over, but generally RED has made the most sense to me in the face of modern Bayer CMOS sensor technologies and their overall approach to over sampling and workflow.

Though I will reiterate, what makes film unique and special is the general nuance of it's well designed colorimetry and tonal response curve, appearance/effect of visual grain, the general negative/positive photographic process (and some of the colors via different development techniques), combined with the unique properties found within the medium such as the effect of the anti-halation layer and what it can do to highlights in particular. In the digital era, film has seen it's best days as when scanning original negative and displaying digitally will net the highest possible quality image. Optical printing begins a cycles of degradation that from my perspective isn't wonderful towards what was originally captured/created.
 
Here is another interesting article about the human eye and how it perceives resolution etc.

Expert considers limits of visual acuity, visibility and optical performance of human eye.

Jack T. Holladay, MD, MSEE, FACS, tackles common questions about human vision and visual acuity.
Ocular Surgery News U.S. Edition, May 10, 2017
Jack T. Holladay, MD, MSEE, FACS

https://www.healio.com/ophthalmology/optics/news/print/ocular-surgery-news/%7B8c0eb2a6-586c-4670-a8c4-ad1ad012aad1%7D/expert-considers-limits-of-visual-acuity-visibility-and-optical-performance-of-human-eye
 
Very interesting comments and information in this thread. The great thing about film is that its aesthetic qualities are independent of its resolving power. 8mm looks way better than standard definition digital, for the most part. You do need a good camera and lens, though.

I've shown this before but it's worth showing again. Look at how good the Leica M8 is (10Mpx, 1.3x crop factor compared to VV) compared to Portra 160, but how far behind it is to Spur Orthopan (a slow b&w emulsion):

http://photo.imx.nl//leica/camera/M8/M8/page22.html

I agree with Graeme that lp/mm is the better metric.
 
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