Month: June 2018

RAW camera files available now

I’ve just setup and new CML site that is linked to the main one.
The new site is specifically for the camera raw files from the Digital Cinematography Evaluation sessions.

At the moment raw files from the 2017 sessions are available, once we have finished the 2018 in a month or so the new files will be uploaded and these will be removed.

The new system is insanely fast with multiple SSD’s and also multiple processors.

I would like to point out that this is a site for grownups, if you don’t know what you’re doing please don’t waste your time.

The files are large, very large, averaging 8GB per file.

I will not be answering queries about these files unless the query is from a CML subscriber.

https://www.cinematography.net

“Filmlook” or TV standard?

I’ve been asking for peoples opinions about what needs to be included in the next camera evaluations but the answers are highly contradictory.

It comes back to the old which do you prefer, the look of film or the look of TV. The majority of people will say film.  Or at least digital images which emulate the look of film.

They then insist that camera evaluations are done using TV charts and to TV levels.

Given that the original rushes will be made available and also 16 bit EXR files the only people looking at the processed results are either those who can’t use the original files for some reason or other and those who can’t be arsed.

The second group can… The first group don’t need to look at something designed to make the cameras look like TV cameras. They need to know that a workflow to get the best film look has been followed. Let’s not get into the pointless argument of what the film or TV looks are, we all know what we mean by those terms.

We then get to the question of where do we put the levels, there are all kinds of answers varying from 30% to 50% but lets make this clear, I’m working within ACES so log levels on a waveform don’t apply. Once an IDT has been applied and we are in ACES space we are working with an environment that has an inherent toe and shoulder and straight middle gamma.

So I’ve gone back to basics. All the years I sot commercials on film and scanned the neg into a video or later digital environment I used a simple reference. The Kodak Gray Scale Plus. They tell you where to put the mid grey part of the chart in very simple terms. I’m looking at the back of one now and it clearly says 122, 122, 122 in 8 bit values. In the past I’ve used 128, 128, 128 and I’ve had a lot of grief about it. It turns out I was bloody close to the recommended Kodak level and far closer than any of the corrections I was being given.

I will not use TV limited charts.

I will try and produce evaluations that look more like the best film that you have seen and less like NHK.

Information or Knowledge?

It’s becoming clear to me that there is a huge confusion between information and knowledge.

Whilst I love the net it is creating a major problem in that by making so much information available so easily a lot of people think that by looking up information on the net they can “know” something.

This is just not true, truly “knowing”something implies understanding and being able to balance one source of information against other source of information and use experience to come to a reasoned and comprehensive understanding of an issue.

It is often possible to get information on the net that “proves” a point of view when in fact on closer examination and filtered through experience it actually proves the opposite.

When I’m teaching workshops and also posting on the net I’m often asked for a reference for what I’m saying. The problem here is what I am saying is based upon 50 years of experience. I’m sure some of that experience is based upon things I have read or seen along the way but specific references? get real! Generally if anyone can be bothered to research deeply enough they can find an actual reference 🙂

The biggest differences between information and knowledge are speed, depth and breadth. I don’t need to look up what the foot candle or lux level of lighting is needed to get a T stop of 8 with EI speed 400 and a shutter of 180, I just know it. I also understand the implications and variables that come from that aperture and shutter angle and what possibilities there are. When I say that I generally expose camera X at an EI of 250 it’s not arbitrary or the result of looking it up on the net. It’s from years of experience and the knowledge of balancing what is best for shooting and what is best for post along with dozens of other variables.

There is no shortcut, it takes time to assimilate enough information and experience to truly have knowledge of it.

Not acknowledging this will lead to incorrect assumptions, embarrassment and pain.

The next camera evaluations

In preparation for the next round of camera evaluations I asked for comments and got a lot regarding the type of charts I was using.

I’ve been thinking a lot about this and I think we may have it all backwards.

Conventional rec 709 TV has a DR of at most 6 stops and if the charts are slavishly adhered to only 5 stops.

However, once the knees and hypergammas etc are taken into account we are actually working with 8 stops at least.

10 bit log-c will contain about 11.5 stops of DR and that’s more than the best available domestically HDR sets can handle.

Of course that limitation isn’t the camera, it’s the record format and that’s why I record RAW for these tests with a few odd exceptions that are forced on me like rendering 6K to 4K before recording.

So what are the tests trying to do?

I think that we, or I, have lost focus on this.

The tests are to find out what the usable DR of the cameras is.
To establish where the highlights actually begin to clip.
To see what colour distortions appear with exposure change.
To see if there are motion artifacts created by the cameras.
To check what happens to skintone with the different cameras and different lighting.
I acknowledge that I can’t check all lighting and camera combinations, although this would be a really useful experiment.

This is why I created the stress test chart, it’s not designed to show how a camera reacts to rec 709 conditions, it’s designed to see how far a camera can be pushed until it breaks.

THAT is what I’m interested in, it’s the kind of information that will affect how I shoot and what I use.

Just as ACES is designed to work regardless of output space, that can be changed later, so the CML tests will be conducted regardless of any “Standards”. We will try and establish the limitations of the cameras.
Of course some of you will only ever see those results within the limitations of a 709 or sRGB environment. They will at least show you what happens within that environment.

For those who want more I will make available both EXR’s in 16 bit ACES and, eventually, the original camera files.

I am now working out how to get the most information out of these evaluations. Part of this will be using a “standard” tungsten light source, the old fashioned kind that creates light by burning something 🙂 It will also involve charts lit at different levels within the one shot.
Which charts is another matter!
I’m leaning towards a CML stress Test and a Macbeth on either side of the frame, one side lit “normally” and one side 3 stops over. In the middle will be a Kodak grey scale plus card as this has been my reference for a very long time. A movement test will be below the Kodak chart. If I can get a small CDM chart then I will probably squeeze it in below the Kodak chart just for the traditionalists. Oh and a CamBelles chart will feature somewhere 🙂

I will also try and do some comparisons between faces lit with tungsten and LED light. This will include the DSC VFX chart.

Next Camera Evaluations – request for comments

First, my apologies for cross posting, but if I can’t break my own rules…I’m also posting on Cinerant.

The next camera evaluations are shooting in three weeks and I’ve been thinking about how to change them from previous ones, bearing in mind comments I’ve received.

I’m going to try to move away from marking =/- on the charts, it will be purely stop and shutter angle for this test.

I will light to 200fc and set the cameras to the manufacturers recommended EI.

We will shoot from T1.5 to T 22 at 180 degrees and then T22 at 90 & 45 degree shutter.

The tests will be shot both tungsten and LED daylight. Tungsten being the most “accurate” source I can use. I’d love to take the tests to Australia to shoot across a window of 11 am to 1pm across the weeks it would take to shoot the tests in real daylight! The LED’s will be the most commonly used and should show what happens in a “real-world” environment.

The evaluations will be available to download as EXR’s in ACES space from the ODN, and hopefully, depending on cost and support, I’ll also make some of the original camera files available. I had intended to do this but we lost a number of sponsors this year and may not be able to afford it.

I will also upload QT files to Vimeo, these will be UHD and 422, I’ll let them convert them to H264, and also H264 directly to YouTube.

The compiled files that I upload will be all matched at 18% grey, matching only the green level as I don’t intend to colour correct them in any way. Everything will go through ACES with standard IDT’s and appropriate ODT’s.

This time I will make observations as to which EI I think the cameras should be exposed at to get the best images, this will be basically based around noise levels.

So if you set the camera to an EI of 800 but the noise is better at 500 I’ll say so, I’ll also upload a LUT that adjust for you setting the camera to 800 and your meter to 500. This will be a LUT in 2 forms, one that is “naked” and just needs to be dropped into the ACES pipeline in Resolve and the other will include the appropriate IDT’s and ODT’s to “correct” the image on 709 monitors on the floor.

I guess I’m going back to the days when I published GRR’s for various film stocks ?

OK, beat me up now.

Cinegear update

It’s 9 days and 5 presentations at 2 conferences later ? that’s not including the panel at CG.

A shattering 2 weeks in total for me.

What is there that sticks in my memory from CG?

Not a lot really.

Lots of lenses, I’ll be interested to see how many are around in a couple of years. Major question about whether lenses can be universal i.e. S35 and FF. Personally I doubt it. Oh you’ll get decent results doing this but I’m not interested in decent results, I aspire to something better.

Just as lenses become more affordable I suspect that for serious cinematographers the use of rental companies for lenses will grow not lessen. This is good news for rental companies as I also suspect that they’re taking a hammering on the camera rental front. Too many decent cameras at affordable prices. Is an extra stop or so worth $70K+? yes I know that there are other issues involved but it seems to me that the distinguishing factor is tending more and more to the glass.

In the dim and distant past I used to swap back and forth between Ultra Primes and S4’s and of course my personal S3’s. Now there are a lot more really good distinctive lenses available. I make the point of distinctive because a bland neutral me too lens is not what I want.

This is why I mentioned rental companies and lenses, I can totally change the look of any camera with the lenses I choose, the choice of camera is becoming less important as they all get so good.

The other main memory from CG is the amount of gimbal kit available, some good and some horrendous. It’s all moving forward at a tremendous rate but I keep seeing abortions of rigs that will have you in the arms of a chiro in a very short time.

Lighting, so many LED’s and still very variable colour. I can’t wait for the Academy to get a move on with SSI, a rating system designed for us, not clothing manufacturers (CRI) or TV stations (TLCI)  but for filmmakers.

Cameras are now all getting so good that the ergonomics and operability in general is becoming a huge factor. There are still to many people more obsessed with how a camera will fit in a drone or a gimbal rather than how it handles in the majority of conditions. It’s great to see cameras that are a decent size that work without the need to hang all kinds of shit off them.

Part of the July camera evaluations will be start-up time and how many add-ons you need to make it useable. I’ll also include weight in a basic shooting configuration including recording media and batteries for X hours of shooting. The X is still to be decided, probably 12…

It’s good to see new filters appearing, thanks Schneider and Tiffen.

Back to lighting, lots of DMX control which is great but maybe not enough rugged basic docco lights with accurate colour and not excessive weight.

The event is just not long enough, there are some great panels but if you want to see the kit you have to skip them and if you want to chat to people, and CG is the best place I know for this, you have to skip the panels and the kit!

It needs to be at least another day, I know that this is a pain for the equipment exhibitors but… Maybe a day of only panels on the Sunday??