Author Topic: color Bars for lcd and monitor config  (Read 7932 times)

Dunc101

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color Bars for lcd and monitor config
« on: December 28, 2012, 10:15:55 AM »
Hi,

I am sorry if this has already been requested but, it would be great to have on screen color bars in ML.
there is a good image here: http://www.richardharringtonblog.com/downloads/Color_Bars_Start.png

Thanks

D

g3gg0

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Re: color Bars for lcd and monitor config
« Reply #1 on: December 28, 2012, 10:31:24 AM »
hi...

uuhm. for what? just save an jpg and let it display?
i dont understand the use case.
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Dunc101

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Re: color Bars for lcd and monitor config
« Reply #2 on: December 28, 2012, 10:49:44 AM »
It just means you have to save a jpg on every card you are using.
If it was built into ML, it would be useful. you could assign a button to color bars and away you go?

D

drapeama

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Re: color Bars for lcd and monitor config
« Reply #3 on: December 29, 2012, 04:48:50 AM »
Ok, but once you've set your colors "properly" using these color bars...the settings are saved in ML Config file, no? So, no particular use of it then. Simply WB if needed and you're good to go, I guess.
I DO IT BECAUSE I CAN. I CAN BECAUSE I WANT TO. I WANT TO BECAUSE YOU SAID I COULDN'T.

scrax

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Re: color Bars for lcd and monitor config
« Reply #4 on: December 29, 2012, 07:19:15 AM »
I've ever asked me why there are those bars shown sometimes before video, you know...

How are they used? I'm curious
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

drapeama

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Re: color Bars for lcd and monitor config
« Reply #5 on: December 29, 2012, 07:35:04 AM »
I DO IT BECAUSE I CAN. I CAN BECAUSE I WANT TO. I WANT TO BECAUSE YOU SAID I COULDN'T.

scrax

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Re: color Bars for lcd and monitor config
« Reply #6 on: December 29, 2012, 07:39:41 AM »
Thank's, interesting but this last line in the wiki article closes the request maybe:

Quote
The Society of Motion Picture and Television Engineers (SMPTE) owns the copyright to the color bars. Licensing must be obtained from SMPTE to use them

but if got it right maybe a cropmark can be done?
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

drapeama

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Re: color Bars for lcd and monitor config
« Reply #7 on: December 29, 2012, 08:28:47 AM »
Thank's, interesting but this last line in the wiki article closes the request maybe:
but if got it right maybe a cropmark can be done?
1) I guess so. But if you take the concept and work from there, could you be exposed to some sue?
2) Of course. Resize the file and use it as a cropmark. Of course, you won't be able to see anything else than this (except the white areas) but it could work. Again, as I said, I don't think it would do anything once you've "calibrated" or set your camera. Except the White Balance, there's not much to set apart from Picture Style.
I DO IT BECAUSE I CAN. I CAN BECAUSE I WANT TO. I WANT TO BECAUSE YOU SAID I COULDN'T.

nanomad

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R: color Bars for lcd and monitor config
« Reply #8 on: December 29, 2012, 11:29:07 AM »
It's what we call gray area.  Given the US copyright issue I wouldn't do it
EOS 1100D | EOS 650 (No, I didn't forget the D) | Ye Olde Canon EF Lenses ('87): 50 f/1.8 - 28 f/2.8 - 70-210 f/4 | EF-S 18-55 f/3.5-5.6 | Metz 36 AF-5

scrax

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Re: R: color Bars for lcd and monitor config
« Reply #9 on: December 29, 2012, 02:47:19 PM »
It's what we call gray area.  Given the US copyright issue I wouldn't do it
I've suggested the cropmark because an user with the legal rights to use the bars can do the cropmark without the needs of adding a feat that would need licensing.
From what I understood this thing is from analog era of tv, so maybe SMPTE don't care anymore even?
I'm using ML2.3 for photography with:
EOS 600DML | EOS 400Dplus | EOS 5D MLbeta5- EF 100mm f/2.8 USM Macro  - EF-S 17-85mm f4-5.6 IS USM - EF 70-200mm f/4 L USM - 580EXII - OsX, PS, LR, RawTherapee, LightZone -no video experience-

nanomad

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R: color Bars for lcd and monitor config
« Reply #10 on: December 29, 2012, 03:04:20 PM »
From the wiki page
color bars
are not copyrightable subject matter (as the
colors used are determined entirely by
technical considerations, and are not the
expression of an author, they fall under the
scenes a faire exception to copyright law)
EOS 1100D | EOS 650 (No, I didn't forget the D) | Ye Olde Canon EF Lenses ('87): 50 f/1.8 - 28 f/2.8 - 70-210 f/4 | EF-S 18-55 f/3.5-5.6 | Metz 36 AF-5

bwatkins

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Where are the color bars?
« Reply #11 on: February 12, 2014, 11:43:37 PM »
Referencing an old thread at:  http://www.magiclantern.fm/forum/index.php?topic=4008.0

I'm surprised this feature is being neglected (as of v2.3NEXT2014.Jan24.5D3113).

I echo the request for SMPTE color bars display in ML (if it has already been added as of this post date, my apologies, but I didn't find it in my brief search for the forums).

To begin with, having a vector scope display and waveform monitor without NTSC color bars is rather pointless, as the whole purpose of having these calibration tools is to compare incoming video with the official standard: which are the color bars.  EX: Color bars show white at both 80 and 100% and blacks at blanking, pedestal and "legal" black (7.5 IRE) - knowing exactly where those levels display on the waveform monitor show me whether my video is over or under exposed, both in terms of luminance and chrominance.  Likewise, showing the camera a color chart, then comparing where the primary and secondary colors display on the vectorscope (in comparison to the color bars) tells me much more precise information about color shifting in a scene that simply white balancing the camera.

While the photo world relies on the Histogram (rather crude IMHO), the professional video world relies on Color Bars.

This is why EVERY professional video camera includes an internal SMPTE/NTSC color bars generator.  Given all the other video engineer features on ML, I was surprised to find this was lacking. 

As regards copyright, SMTP, here's what SMTP says:

"Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License."

Bottom line: If you don't muck it up with logos or any other superfluous text, it's yours free to use.

The suggestion to simply copy a color bars JPEG to a media card then play it back is fine, but asking a camera user to be responsible for this when ML has taken responsibility for so many other wonderful features seems a bit strange - not to mention the hassle it is to make sure you have an accurate rendition of the color bars, be sure to put it on the same SD Card as the ML Firmware, and don't mind having to go in to manually toggle playback from that card.  Not something I'd want to be stuck doing while on a shoot.