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Aligning a Varicam
Hey guys,
The shop I work at just got a new Varicam H model. We have a Chroma Dumonde Chart and the whole set up, I was wondering if anyone had a link or reference that would give me a run down on how to align the camera. I was fortunate enough to attend one day of the Varicamp in dallas back in october, but I only got to go to one day (I went free through my employer) and I missed the part where they talked about setting the gamma and things before you “make the meatball” on the vectorscope. I tried doing a search and couldnt find a thread about this, Thanks for your help guys.
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9 Replies
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Ian,
It’s not really completely possible to explain this in a short reply over the internet, but here’s a short version:
The Varicam comes from the factory with a rather “bland” camera setup, namely that the Matrix is off and otherwise set to all zeros. The elegance of the DSC Chroma du Monde chart is that it allows you to build a Matrix setting that most accurately reproduces color and gives skin tone a pleasing quality.
To do this you must otherwise set the camera up completely, meaning the dynamic range that you intend to use and the gamma setting. This is not always completely self-evident, as these settings really depend on the eventual use of the footage, specifically whether you seek a what-you-see-is-what-you-get (WYSIWUG) look or a low contrast master for filmout. Assuming the former (which is really 99% of the use of this camera) I recommend a Dynamic Range setting of 200. While this is the minimum of the Film Gamma effect, it still causes something of a washed out look. To adjust that. I usually “crush” the gamma a little bit.
By looking at a properly lit and exposed DSC chart and observing on the waveform, I’ll adjust the Gamma to cross over at 50 or 55% depending on how “crunchy” a look I’m after for the scene.
Now it’s time to build your matrix. Set the Vectorscope to variable gain and adjust it to 1.870x. This is the setting that when used in conjunction with the Chroma du Monde allows the color to be adjusted nominally. First turn on the matrix and color correction in the low/mid/high sections of the first page menu. Then use the matrix to grow the “meatball” as best you can into the six boxes on the scope. This will take several gorounds. It not not be perfect, that’s what the next adjustment will do.
Once you’ve done this use the next color correction to adjust the six points even better into the boxes and finally the last color correction to adjust the three colors between each box into the best and most evenly spaced line as possible.
It’ll take some time and patience to do all this, but you will definitely create a more colorful look than the out-of-the-box camera. You can always return to factory set by resetting the camera (pg 4) or by turning off the matrix and color correction in the l/m/h lines.
If you like what you’ve created, save it as a scene file on your card and in the internal memory, giving it a title indicating the colorful look or matrix on.
If you don’t understand or are frustrated by failure, the best thing is still to hire a skilled Varicam specialist to allow you to watch them setup the camera, there’s nothing like this one-on-one relationship and q and a that naturally occurs to assist in learning what is really an art, yet portrayed as a science!
Hope this helps.
JS
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Hey John,
Thanks for the reply, Im following everything youre saying, as I was going through it my only question is, what is the correct exposure for the grey card? 50% IRE for the grey chip or 100% IRE for the white chip? As I was looking around I found one place that suggested 100% IRE for white yet another said 50% for the grey. I ran through the set up process as you said based on 50% IRE grey and I felt like i had to jack the matrix and CC menus up pretty high to get them into their boxes (many of the matrix and CC options were maxed out). I look at the image and the colors look good, the skin tones are nice, Im just wondering if that sounds normal, to have several of the menu items maxed out like that.
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Ian,
Good questions!
As regards the exposure. With a chip chart, which is designed (grey scale) to represent a more limited range of contrast than exists in the real world, you do want to set the white chips at 100%. This assumes that the knee is off or the dynamic range is limited. You’ll notice that if you run the dynamic range with this setting (even with the exposure adjusted for the sensitivity loss by resetting the crossover to the same 50%) it will crush the highlight while leaving the mid tone constant. This is to allow you to extend the dynamic range in the real world, where a bright sky or a white shirt may find itself in your otherwise properly exposed shot.
To continue, a properly exposed face in HD comes in at 50-55%, so again, in the real world that is how you’ll want to set your exposure. The Panasonic 8.4″ LCD with its waveform function is very useful in this regard. You’ll find that setting exposure is fundamentally different than it was with your Betacam, where we’d use the Zebra set at 98-100ire to set the exposure of the brightest part of the scene; with the HD it’s important not to clip the brights but it’s equally important not to overexpose the face.
About the matrix; yes it’s perfectly normal to almost reach the maximum setting (+31) on several of the Matrix levels. You should also notice, and pay attention to the fact that as you crush the gamma (higher number) you also increase the color saturation. and you’ll find this a very powerful control in “painting” your pictures. The problem is to keep it consistent within each project.
The Varicam does lack an overall “saturation” control which would be very helpful in making adjustments to the color as you crush or press the gamma. I’ve complain vociferously to Panasonic about this and they’re considering adding this control to later models…we’ll see. Even Sony, who did respond to this request has added only “desaturation” in a misguided attempt to prevent “illegal color gamet” as if such a thing existed in digital broadcast or digital cinema.
You’re well on your way to making some beautiful pictures!
JS
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Alright,
Went back through with the few tweaks I saw in your post. So just to recapturn off the knee, set the exposure to 100% IRE for white, set gamma so your cross is at 50-55% and from there go in and align the colors?
Thats what I did and I seemed to get a lot more lattitude in the highlights, the colors looked good, good skin tones.
I appreciate your help in this John, youve been a life saver.
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You really should hire a qualified video engineer or experienced DIT who really knows the Varicam.
A one day course is no excuse for years of “real world” experience.
Tony Salgado
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I trust John!
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Ian,
I appreciate your vote of confidence and I’ll just add that both positions are tenable; namely figuring it out yourself, by trial, error and observation (a great way to learn) or by looking over the shoulder of a skilled engineer (like Tony S) and asking a lot of questions. I have to admit that what I know is a result of doing both!
JS
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does this mean did something wrong to the camera?
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Just for grins…. What is the electrical difference between the “F” and the “H” versions of the camera?
I’d love to see what settings you end up with on matrix settings. I was looking for an overall chroma boost in our “F” model, and it looked to be a combination of about 26 settings each at same setting… Or did I miss something obvious?
Jan
Looking for 1939 Indian Motocycle
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