Log and Linear

[Finner]

I was involved in some comparison testing of the D20 this past weekend. Below are some pics and I have some questions for RED.

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The D20 has a "LOG" form of RAW and a "LINEAR" outputs. Linear is a preset L.U.T. corrected output and the log an unprocessed output like RED's RAW. Having these 2 outputs is a bonus. The LOG image looks like crap it is flat but is a much better image then the linear because it can have the LUT of your choice added in post. There is one major problem with this though a producer or client or agency person when they look at a "LOG" or "RAW" image on a monitor on set will be shocked when they see something that looks like poo-poo. Now we all know better because after post the image will look much better then the linear image that has had a preset LUT assesed to it but as many have experienced before some people can not get there head around LUTs and the understanding that it will look better later. Many of the people who sign our checks want to see a perfect image right on set. ARRI has made this possible by giving you the choice of linear to view a preset LUT image on a set monitor even though you are recording in RAW and can process later. A feature like this would be very helpful to keep some of the above the line people from having heart attacks when they see a RAW image.

Is RED going to offer a linear monitor viewing option on the camera?






Test info.

The 435 had 200T vision II film so it will come as close as possible to a match for the D20's 200 asa sensor.

The D20 is an amazing digital cinema camera. It is set up very production friendly and will work well. ARRI is by far the smartest camera company out. ARRI stands above all other HD and and film camera companys out there 9 (currently production offered camera companys) . ARRI thinks over there cameras very well and built the D20 be upgradeable and last for many years. The fantastic thing about this is that the RED is pretty much a mirror image of a D20 with a 4k sensor rather then ARRI's almost 3K. It is so good to see RED with a similar system to ARRI. ARRI has hardly ever made a mistake in the development of their cameras and to it is so easy to see that the D20 and RED are the future of cinema advancement. Even better though is the ability to own a RED at 1/10 the price of the ARRI.

As far as I could tell the only real advantage the D20 has over the RED is an optical viewfinder. Everything else from what I can tell I give the advantage to RED. Now before Graham or another RED representitive jumps on me telling me all about the video focus assist feature I know, but until I actually use a focus assist that works well I will not buy that a EVF with focus assist will be as good or better then an optical viewfinder.

So other then a viewfinder I feel (according to RED's current stats) that RED has the edge. I still want to see much more image results and do some tests of RED though to be absolutely sure. The other thing I would like to to stack up is camera to camera contrast comparisons as high resolution is great but if contrast is bad no amount of resolution will help.


By the way RED I am not complaining about you not implementing an optical viewfinder. Quite the opposite, because I would not want to have to pay the kind of $$$ it would take for the RED to have an optical viewfinder. It would just not be worth it.

 

[Damien Molineaux]

Thanks for sharing dude, now I recognize your avatar, nice one!

New shit may have come to light, but I believe it ain't nothin' compared to what's about to hit the fan!

Looking forward to the OK corral shoot out between all the high end digital cinema cameras once Red is out.

Cheers,
Damien

 

[Pol Turrents]

I don't agree with your thoughts about the D20.
Here in Spain we did tests with the arri camera (with final 35mm copy) and the results were VERY disapointing a poor.
We had to shoot to a HDCAM SRW1 recorder and the Arri DIT asked us to work always with the lineal curve, wich is TERRIBLE, specially in low light.
In other hand the Arri sensor is 3k, but for now, you have to work always in 1080 mode... So, if the red specs are real (sorry for the doubt!), this camera it's going to be a blast, specially if we think that renting a D20 for a movie can cost like buying a few reds!
And about the optical VF... I've did a few movies with varicam and F900, and I've never missed it a lot... it's useful, but, if it's only for safety, I think (red guys, correct me if I'm wrong) that you can choose to shoot 4k+ and then crop to 4k

 

[Finner]

I don't agree with your thoughts about the D20.
Here in Spain we did tests with the arri camera (with final 35mm copy) and the results were VERY disapointing a poor.
We had to shoot to a HDCAM SRW1 recorder and the Arri DIT asked us to work always with the lineal curve, wich is TERRIBLE, specially in low light.
In other hand the Arri sensor is 3k, but for now, you have to work always in 1080 mode... So, if the red specs are real (sorry for the doubt!), this camera it's going to be a blast, specially if we think that renting a D20 for a movie can cost like buying a few reds!
And about the optical VF... I've did a few movies with varicam and F900, and I've never missed it a lot... it's useful, but, if it's only for safety, I think (red guys, correct me if I'm wrong) that you can choose to shoot 4k+ and then crop to 4k

Results have not come back from the lab yet on the test so I can not comment on the images yet. If you read what I said you will see that my comments were on the user freindly system of the D20 and that the way it works is very good, nothing about the image as it has not yet been compared. So if you are disagreeing with my comment that the D20 is not a well thought out digital system then I guess you are saying the same about the RED as the way the system design is virtually the same.

The viewfinder comment I can totally understand if you thought the 900 and verri was as good as an optical viewfinder as there are some pretty bad optical finders out there. I can assure you though that the newer ARRI and Panavision optical finders are incredible and I have compared them side by side and the 900 and verri do not even compare. In the test I mention above we also had a sony 900H and I can assure you the sony viewfinder did not look 1/4 as good as the optical 435 and D20.

 

[Pol Turrents]

well... I haven't tried the new ones from panavision, but the last time that I shoot with a panaflex, it was a nightmare to see anything in low light (well, it's been a long time since my last shooting in 35mm!).
I always try to work with the accuscene VF. It's not only the best VF I've ever seen, but an INCREDIBLE tool to help the exposure. If I had to choose between an accuscene and and optical viewfinder with a moving mirror... I don't have any doubts.

 

[Alex Boothby]

Is RED going to offer a linear monitor viewing option on the camera?

I do believe that RED has exactly this function, although they have used different terminology. As I understand it, your RAW image can be displayed on set with a monitor LUT which is a user preset setting imported from REDCINE. I imagine that RED will ship with some basic presets (daylight, tungsten night, florescent, etc.) and that users can also create their own LUTs in REDCINE - although this is partly speculation. This monitor LUT will be imbedded with the captured RAW footage as metadata which will travel with the footage. This means that the monitor LUT used on set will also 'pop up' during dailies in REDCINE, at which point the LUT can be tweaked or totally re-done. The idea is that the 12 bit linear or 10 log RAW data will always maintain the full range of the "digital negative' although it can be displayed numerous different ways.

I hope I'm understanding this right because it sounds great.

 

[Alex Boothby]

I imagine that RED will ship with some basic presets (daylight, tungsten night, florescent, etc.) and that users can also create their own LUTs in REDCINE - although this is partly speculation

I remember in the early days of HD, DOP Dean Cundey packaged up some of his F900 settings and sold them as the "Cundey Look" They even made their way onto ebay. I've worked with Cundey a few times and he is a great guy - but this did make me laugh a bit.

 

[Alex Boothby]

This monitor LUT will be imbedded with the captured RAW footage as metadata which will travel with the footage. This means that the monitor LUT used on set will also 'pop up' during dailies in REDCINE, at which point the LUT can be tweaked or totally re-done.

Again, I hope I haven't butchered the nature of this exciting feature. Please correct me if I am mistaken.

I do have one question / request - if the on set-monitor LUT travels with the RAW footage as metadata, could any REDCINE tweaks or changes be saved as a second level of metadata? Put another way - will any color changes in REDCINE overwrite the original "on set" monitor LUT? I hope not. That way if the REDCINE colorist makes any drastic changes, and the production wishes to return to the "on set look", these settings could still be recovered deep in the metadata.

 

[Damien Molineaux]

I do believe that RED has exactly this function, although they have used different terminology. As I understand it, your RAW image can be displayed on set with a monitor LUT which is a user preset setting imported from REDCINE.
...

I've been wonderiing about this, it has been said that while shooting (4k red raw for example) it would be possible to view footage via a SDI output, however looking at the format option chart on red.com, I read that when shooting any one of the three raw formats, the HD-SDI output does not function. Am I not reading this correctly ?

Click on the thumbnail below to see the portion of the chart I'm refering to.

About the LUT thing, I remember a thread (on DVXuser probably) talking about monitors with LUT settings, so you could change or preload the look you want.

Cheers,
Damien

 

[Sanjin Jukic]

Finner, thanks.

Waiting to read about your comparison test results.

 

[P Andersson]

Put another way - will any color changes in REDCINE overwrite the original "on set" monitor LUT? I hope not. That way if the REDCINE colorist makes any drastic changes, and the production wishes to return to the "on set look", these settings could still be recovered deep in the metadata.

great comment boothba

I have been wondering about how to store different versions of luts, perhaps as multiple "history states" with options to store them in the raw file itself and/or export them to apply to other scenes.

There is also the functionality of having a lut change over the length of a scene, like a gradual adjustments with keyframes, would be great if this was possible with curves.

just to give an example, if you shoot somebody walking out from inside a dark room, you might want to export this with an adjusted lut that changes over time to give more contrast in an softly lit interior, to a gentler curved highlight as you come out in a sunlit sky, after a testrun or two you might want to go back to a previous version, without having to look through folders anywhere it would be convenient to have the history right there in the file

 

[Carlo Rho]

Hi Earthling,
I think that this part of the "Format Option Chart" is referred to recordable output.
I can't remember now where but I'm pretty sure to have read something about DVI-HDMI monitor output.
Ciao Carlo

 

[Jeff Kilgroe]

I've been wonderiing about this, it has been said that while shooting (4k red raw for example) it would be possible to view footage via a SDI output, however looking at the format option chart on red.com, I read that when shooting any one of the three raw formats, the HD-SDI output does not function. Am I not reading this correctly ?

I think you'll be able to monitor the camera via SDI and/or HDMI outputs regardless of what format you're recording in. But you obviously won't get the full 4K resolution out of either of those two interfaces - just not enough bandwidth and not supported by the interface standards.

 

[SF Geek]

I remember it stated that all of the outputs on the red camera, besides the raw port, firewire, and sata will output an RGB corrected image with whatever pre-selected LUT you have chosen to apply. You could use those ports for monitoring or recording to a deck while recording the RED Raw image to drive or flash or whatever.

 

[SF Geek]

You beat me to it Jeff

 

[Steve Freebairn]

Couldn't something like the HDLink (with it's changeable LUTs) change the log image to whatever you want?

 

[Stuart English]

LOG and LIN

LOG and LIN

Yes we do have that same concept, although its subtley different in our case.

The RAW data is recorded in a true linear fashion at 12 bits per pixel depth.

The RAW data is also converted to HD resolution RGB at 10 bits per pixel using a LUT, which in its default mode creates a gamma corrected REC 709 signal - which misleadingly is also called "linear" if you are using standard video terminology.

This signal is what is monitored on the EVF, LCD, HDMI and Preview HD-SDI outputs.

The Dual Link HD-SDI output is independent of these and the chart indicated that it only operates if you are recording 720p or 1080p.

 

[Finner]

The RAW data is also converted to HD resolution RGB at 10 bits per pixel using a LUT, which in its default mode creates a gamma corrected REC 709 signal - which misleadingly is also called "linear" if you are using standard video terminology.

Sounds good Stuart

The converted HD with a LUT you mention. You mention that the LUT has a default setting so I assume you can also input a LUT that you have created yourself?

This would be helpful as then there would be far less misunderstandings of image "look" plans.

Also is it possible to save a few LUT options in the camera? If so how many?

Thanks Stuart

 

[Pol Turrents]

are we talking about a 1D LUT, I supose...
BTW I've been making tests of using LUT's on set with the panasonic gamma box. Maybe we can use it with the red too.

 

[Stuart English]

LUTs

LUTs

We are still working through the details, but yes it is intended that a limited number of "LUTs" can be stored in the camera, ingested via SD Memory Card / wireless / USB-2 types of data paths. Intent is to allow a few preset "looks" to be captured so the guys on set can visualize what a color corrected RAW data recording will look like once it gets to post.