TrueColor V3.0 available on-line

[K. Forman]

Thanks again Paolo. It never hurts to get a second, or third opinion.

[Steve Mullen]

Originally Posted by Paolo Ciccone

I just wanted to highlight, in case is not clear to everybody, that different shutter speed implies more/less light exposing the "frame" and that explains the difference in ISO rating.

It sure isn't clear to me.

A camera should, except for differences in gamma and perhaps maximum IRE level, have a constant ASA. This value we dial into a meter.

Now we set the shutter-speed on the camera and on the meter.

Next we measure the light (e.g., EV).

Then we dial in the EV and read-out the F-stop.

+++++++++++

Although the gamma curve and perhaps maximum IRE level are believed to alter camera ASA -- I haven't seen how the gamma curves value and clipping level can computationally convert one ASA to the other.

In short, it seems a good theory -- but I haven't seen anyone actually compute the two ASA values from the gamma curves and perhaps maximum IRE levels. I don't even know how to compute this.

But, one should be able to build a logicical agruement of how gamma curve A and a clipping level A should be able to move the "A" ASA lower or higher than the "B" ASA which uses gamma curve B and a clipping level B.

[Paolo Ciccone]

Originally Posted by Steve Mullen

A camera should, except for differences in gamma and perhaps maximum IRE level, have a constant ASA. This value we dial into a meter.

Hmmm. A faster shutter speed brings in less light. This produces a different , lower, signal from the CCD. That's the best way I can describe it.
If you keep the frame rate constant, say 24fps, a 1/48 shutter speed is your baseline, say 200 ISO, at 1/96 you reduce the amount of light by one stop and you'll have 100 ISO.

[Steve Mullen]

Originally Posted by Paolo Ciccone

Hmmm. A faster shutter speed brings in less light.

Yes, but that has nothing to do with ASA. The first step is to set ASA on your meter. It never changes for a given film nor should it for a given camera electronics.

Light-level is dialed in from the measure. Then shutter-speed vs Iris are recriprical.

I'm still back at the CLAIM a camera has different sensitivity values based upon the chosen gamma curve and/or clip setting. Gamma curves have a number that represents the curve. Like 1.8 or 2.0.

Does anyone know what this value means?

Does anyone know HOW this number would alter camera sensitivity? If the number is larger does it increase or decrease sensitivity. What is the equation for this?

What are the values of the two gamma curves that have been used for the testing. For example, what is the value of CineGamma?

If one understands all this, it should be possible to compute an ASA at one gamma from the ASA at the other gamma. If one can compute -- then it validates the verbal explanation. Without a math proof, it's all just words to me.

[Joshua Clarke]

Paolo,

We were doing some camera tests using TCV3 and Mr. Dashwood's Warm .scn files. I have not yet been able to color and grade the footage yet, but I'd like to get your input on something.

I'm really impressed with how your TCV3 renders colors and I would very much like to use it for the commercial we will be shooting soon. But one thing bothers me - we shot and will be shooting under 3200K lighting and implementing a hot window behind the subject, similar to the images I've included below. While white balancing the camera for 3200K and implementing TCV3, the background outside goes a little.... or a lot.... turquoise.

http://www.sect1.com/files/josh/take_one.jpg

Compare that to Mr. Dashwood's Warm .scn file, which has a much more pleasant bluish cast.

http://www.sect1.com/files/josh/take_two.jpg

When it comes time to shoot, I will be placing Rosco 3411 (3/4 CTO) on the window to drop the skylight down in color a bit, and obviously that will affect the color - I'm just not sure in what way because the gel has yet to arrive and I'm unable to test it.

I'm wondering if you've had a similar experience with mixed sources and the TCV3 settings and/or any advice to give me. Thanks, you've already been a great help with the work you've done on the .scn files.

[Paolo Ciccone]

Joshua.
This is a rather simple case to test. Go outside and white balance for that light and check the colors. You are mixing two different color temperatures here so I'm not surprised of the result. As you mentioned, adding gel to the windows and bringing the same color of light will solve the problem. Another approach that you can use is by using daylight balanced lights to light the interior scene. Both LitePanels and Kinoflows can be used for that.

[Joshua Clarke]

Paolo,

Forgive me if I wasn't clear enough on my first post. I'd like the window to be cooler, but the hue that daylight is rendered while white balanced to 3200 is a little too turquoise under TCV3 for my tastes. I was looking to match the discrepancy in color temps more like Mr. Dashwood's Warm settings, where the blue is paler. Or would any attempt to alter the color matrix negate the affect of "true color?"

Thanks for your help.

[Paolo Ciccone]

TrueColor is just a starting point, I tweak it from time to time. For example, I had to alter the level of the blues in order to get some reds to display the way I wanted. The important thing is to do it in a controlled environment. All the settings for gain and rotation affects each other. Think of a rubber band stretched around six poles. If you move one pole the tension at the other points changes. In order to make a change to one parameter you need to look at the result on a Vectorscope.

Good luck.

[Joshua Clarke]

Paolo, thank you very much. Guess I'll have to wait until the gels come in.

[Jeffrey Butler]

So what about the 250 w/ the 17x5 HD lens? Will your settings hold up to the new lens? I'm sure it's going to affect something...and what about the 250 in general? What would you expect to happen if I loaded them onto one?

Are these settings specific to the 100? I'm learning from you, man - thanks.

[Jack Walker]

Originally Posted by Joshua Clarke

Paolo, thank you very much. Guess I'll have to wait until the gels come in.

I think your blues are closer than you realize. The one shot with TC3 is a lot more saturated, bringing up the "turqoise." However, I think the darker blue and the turquoise blue compared next to each other are about the same.

When you turn down the saturation of the TC3 image in Photoshop, or another image program, aren't the blues in the two pictures matching in hue better?

[Scott Shuster]

Paolo, your suggested settings bring spectacular improvement. My staff and I have EVERYTHING to learn about the technology of color in our cameras. That is, we know NOTHING about it. But by simply implementing your suggested settings for the GY-HD100U found in the watermarked chart at this location:
http://www.paolociccone.com/hd100-calibration-3.html
...we have improved our color from 'poor' to 'spectacular.'

We had been wondering why the color was not quite what we expected from this wonderful camera. I still don't know "why"...but I do know now what to do to fix it...thanks to you, Paolo.

Bravo, Paolo! È la gente come chi, che ripartiscono la loro ricchezza di conoscenza, che fa il la maggior parte per rendere a questo mondo un posto migliore, giornaliere.

Riconoscente, --Scott

[Michael Escher]

Are the truecolor 3 settings written for the compression that occurs when you record to tape as opposed to doing direct capture to either something like the Firestore DR-HD100 or on to a laptop via Scopebox? Or would they be considered to be the optimum settings to record directly to disk as well? If not, has anyone done something similar for recording directly to disk?

[Paolo Ciccone]

There are no settings written for compression or not. Please refer to the article that I wrote about TrueColor, http://www.paolociccone.com
The configuration has been designed to be the most neutral, true to 1:1 representation that the HD100 can achieve. This is not changed by the compression. On the other hand capturing component out at 4:2:2 will allow you to preserve more color information and TrueColor is designed to avoid data loss.
BTW, while I initially designed TrueColor with the smaller DSC chart, I recently tested him with with the 28-Color and I'm happy to report that it actually held very well. I might tweak it a bit later but it's a very solid configuraration.

[Paolo Ciccone]

Scott, I don't think I replied to this before, I just saw it. Thank for the kind words.

Originally Posted by Scott Shuster

I still don't know "why"...but I do know now what to do to fix it...thanks to you, Paolo.

Very few cameras come out of the factory correctly calibrated and "correctly" is a subjective term. Some people could argue that just having the camera reproducing reality is not really their target. I suspect that some of the defaults in these cameras depend on someone's idea of what is most likely to meet the taste of the target audience and sometimes these ideas can be totally off, as it is in the case of the HD100. In my way of shooting I like to have the least amount of "interference" from the camera so that I can set up the scene and light it create the mood that I want and if my eyes like what I see then the camera should save that image.

Bravo, Paolo! È la gente come chi, che ripartiscono la loro ricchezza di conoscenza, che fa il la maggior parte per rendere a questo mondo un posto migliore, giornaliere.

Il piacere e' tutto mio, Scott. :)