DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   JVC GY-HD Series Camera Systems (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/)
-   -   How to create scene files from scratch (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/87391-how-create-scene-files-scratch.html)

Stil Williams February 23rd, 2007 04:56 PM

How to create scene files from scratch
 
Greetings.

I have been reading these forums and find it very thoughtful that members would create scene files and have a link for them for others to download and use, absolutely amazing !
At present i do not have my own camera as yet, however am looking towards the GY HD, as it offers the most flexible under 10K.

I want to learn how to do this myself, and what is needed to create these files, i.e charts, test gear etc...

1) Creating scene files is this applicable to "pro" cameras such as F900s, sony 750s and pannys ? and is the technique principally the same ?

2) I see the use of of wave forms and vectors, and DV Rack is being used. How does this compare to using hardware tektronix test gear.

Regards

Stil.

Stil Williams February 24th, 2007 01:55 AM

Tim, Stephen, Paolo, anyone ?... Is this the case where i am only eat fish and never really taught to fish for myself ?

Sean Adair February 24th, 2007 11:32 AM

here's a crumb!
 
Paulo's website ( http://www.paolociccone.com ) has very detailed information about how he went about creating his settings - in fact Tim Dashwoods first post about recipes has links plenty of solid info
http://www.dvinfo.net/conf/showthread.php?t=62835

There is a ton on this forum if you crawl the the discussions about tweaking scene files - the one above and for instance this:
http://www.dvinfo.net/conf/showthread.php?p=475033
on the truecolor scene file.

I have the HD200, and scene files written for the HD100 need to be modified for the 200/250 since the ranges have changed and DSP is different. I've just started inputting a few of the color settings manually and getting a feel for them, but without a color chart and a bunch of time, I know I'm still "fishing"
I'm really looking forward to these guys starting to publish settings (I know they have the new cameras in their paws!) so at least I have some templates to start tweaking from. I think there is a lot to learn by loading up a recipe, and then tweaking/examining to see what made it tick.

I think the proccess is fairly similar to the "big" pro cameras. I've used these cameras with custom presets, but haven't written the settings.
A good color chart and well calibrated monitor seem to be the primary external tools. DV rack or one of the equivalent scoping utilities (mac users check out http://www.scopebox.com/ ) would seem to be useful too.

Stil Williams February 24th, 2007 01:07 PM

one mans' crumb is anothers mans' meal
 
This is what i have been looking for Sean. You call it a crumb, but a crumb to a "hungry" man makes a big difference. i missed paolos' site and breakdown.

Much appreciated

Thanks.



Stil.

Tim Dashwood February 24th, 2007 05:47 PM

Quote:

Originally Posted by Stil Williams
I want to learn how to do this myself, and what is needed to create these files, i.e charts, test gear etc...

Hi Stil.

I created my first batch of scene files with a Macbeth chart and a linear grad that I printed myself. The idea was to "map" the effects of the the controls on the waveform/vecorscope. Just step through this quicktime one frame at a time to see the results from the HD100.
After obtaining this data is was very easy to create the "wide-latitude" & "Low-Light" settings. (Keep in mind that I didn't touch the colour matrix controls for those settings, so use one of Paulo's scene files if you are seeking a "real" look instead of a "cine" look.)
I used similar data I obtained from the DVX100A to compare and create the DVX-Match settings.

For phase 2, I programmed some "creative looks". There seemed to be a demand for scene files that emulate in-camera some of the popular looks of feature films. The obvious ones were bleach-bypass and cross-processed reversal, but I also created some looks for "Amelie" and "The Matrix."
My process was to use a base-line scene file to shoot some material and a macbeth chart. I then colour corrected the scene in FCP the way I percieved the different looks (using my huge DVD library for reference.) I then applied those same colour corrections to the macbeth chart I had shot and took frame grabs of the waveform/vectorscope images.
I then matched the settings in-camera to the waveform/vectorscope frame grabs I had taken of the colour corrected material. Many volunteers on this board tested those scene files in various locations around the world and when I was confident the looks actually worked I posted them.

My next task is to create HD200/250 equivalents of those scene files using the data collected over a year ago. This will allow multi-cam shoots with HD200/250 combined with HD100/110. I may also come up with some additional files for the HD200/250 that utilize the new controls.
Priority one is reducing the extra noise the HD200/250 seem to have. I think it may have something to do with the V detail setting. More on that later...

Stil Williams February 25th, 2007 05:07 AM

Quite a bit to take in, so from crumbs to feasts. I will read through and get a few practice runs in, when i am finish i will post the results, it will be good to get some feedback . Let me get this in the know first, before i ask anymore questions.

There is a shoot scheduled in a few months or so, and the producer wanted to shoot with a "small" camera and create a "big" look. The responsibilty has been given to me. i have used very much everything on the market apart from the JVC and am seriously considering it not only for myself but for this shoot.

Chances are i will use your settings and a credit you for them.

one final question though, when creating scene files does it matter what glass or adapter is on the front, also i see 3200 k being used, any particular reason why ?

Thanks for the info Tim.


Stil.

Sean Adair February 25th, 2007 08:34 AM

scene files redux
 
I'm a total noobie at this, but I'll jump in with what I know. The scene files overwrite a set of "preferences" that are set in the camera user menu. This camera has ND filters, but WB preset color is done electronicaly - and this is one of those settings. In fact, there are a number of "personal" and individual preferences that get overwritten when you load a scene file. All the more reason to get familiar with the settings, and customize them to your personal needs. The crucial information in creating looks is of course in the Blacks, gamma and color proccessing (etc) settings. BUT, even the user button switch settings change with a scene load, and the last thing a stressed out camera op needs is having his switches scrambled randomly! (my own earliest written scene files came back to haunt me already with unexpected changes)
Regarding the realtion to optics:
There is a setting on the 200/250 called white shading, which is a compensation for different lenses optical weaknesses in top to bottom color. If this setting is significantly different for lenses you are using on a project, you may want to create a different set for each lens. There will also certainly be differences in color and contrast going from a dedicated lens to an adapter with primes - to a lesser extant changing any lenses. You may even want to make some adjustments there.
After all, the cards are cheap (under $10- limit of 4 settings on a card of any size), so you could have a card for each lens system with your prefered settings. Or just match them in post... (before someone else chimes in with that!).
One of the real considerations is what kind and how much grading will be done in post anyway. One approach is to create settings that allow the camera to capture the most dynamic range with neutral color - allowing more bits for post-processing. This approach still begs for optimization to specific conditions - low light, bright contrasty situations etc.
Then, there is the possibility to get some very creative filmic looks directly in the camera. Changing your mind later might not be so easy, but that's the film aesthetic anyway!
Apologies to those I've paraphrased - much of this is already here - writing it out in my own words is just helping me grok it better!

Stil Williams February 25th, 2007 09:43 AM

is the white shading operation the same as this

http://www.zgc.com/zgc.nsf/c7a682995...f?OpenDocument

just to clear things up a bit, this is a known problem with older lenses like from the 60s / 70s, we did not have aproblem with super speeds.

which i believe it is. This is not for the faint hearted and be prepared to give up a day or two. i learnt lens files the hard way with a facility with dsr 570s, operators would hit the master reset in the engineering menu (hold down menu wheel and power up ). which blew away the lens files. They can not be stored except for in camera as far as i know (sony 500, 570, 750, 900). The last calibration took the engineer 12 hours, and me probaly twice that. its a pain staking process. the last 750 i hired had lens files for cine J21, J11, J
19, and A10 lenses, and i just changed the lens file when i went with the wangle.

Maybe this should be taken into account when creating scene files.

I spoken with the director and Dp and they stil have not decided whether to do in camera grades or not.

Paolo Ciccone February 25th, 2007 01:36 PM

Quote:

Originally Posted by Stil Williams
I spoken with the director and Dp and they stil have not decided whether to do in camera grades or not.

I would stay away from it. Grading is something that should be done in software. Keep the camera as neutral as possible except for filtration. In a few situation, for example bright daylight, you might want to change parameters like the knee function in order to preserve highlights. Same if you shoot situations with very high contrast ratio, like concerts. Revert to a "reasonable" knee when working in a controlled lighting situation.


All times are GMT -6. The time now is 01:49 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network