Try "crop, scale and position" to zoom in on the chart.
However, I find it's UI (parameters) a bit clumsy, the scaling works from the edge (not the center) and shifts are called "tilt", and for big enlargements the shifts are not enough to bring any part in the center etc.

I tried pan&zoom too, but the scopes somehow don't change?? ***

For new shots, try to zoom in on the chart already with the camera.

Having the chart fill the frame, it is easier to identify the parts of the chart on the scopes.

Concerning point [5] above, it seems that the vectorscope, which the author used, has a "zoom in" option, this would be equivalent to chroma gain, or increased saturation.
On the Kdenlive vectorscope, you can do this using the slider on the right side.


*** playing with it some more, I found that the scopes (RGB parade and vectorscope) often do not react to the applied effects (like RGB adjust or SOPSAT), although I can see the colors change in the project monitor.
Switching to clip monitor and back seems to help...

This was with a script compile from 20130206
Compiled a new one today (20130225) Now the scopes are more responsive, but they seem to show the same signal in all three channels, R=G=B in the parade, and the vectorscope always shows a symmetric "mercedes star".

The channels on the scopes seem OK on the 20130206 version, but as I wrote above, they aren't always updated after the addition of an effect.


Disclaimer: I am compiling this on an old, heavily patched Opensuse system... although I changed nothing on the system between the two compilings above.

Many thanks yellow and Marko!

yellow - I was trying both effect but I could not manage to change anything :(

Marko - Crop, Scale and Position did the job! This is enough form me at this step :)
I had the same problem like you said in *** in your post but switching to clip monitor and back help to me as well.

So I am playing with a new skills and will ask some more question Tomorrow, on my way to go from this:
http://provideocoalition.com/images/uploads/OSC_Before.jpg
to this
http://provideocoalition.com/images/uploads/OSC_After.jpg
but not with Apple software but with KDENLIVE!

:))))

hi, the edge crop effect under crop & transform works fine for zooming in on the chart. You can control left, right, top & bottom, tick the use project resolution and you get zoom with those images.

Then the 3 point balance effect will let you sample, white, black and 18% grey for primary correction.

Thanks yellow,

Edge Crops also works pretty well :)

:) :) :)

For manual correction, as in the first link (what good is....):

The signal in a channel is a product of incident light and object reflectivity. So, if the cast is the result of unbalanced light, the right thing for correcting this would be to change channel gains (the diagonal elements in the linear color transform matrix).

To do this you can either use RGB adjust, and set the mode to "multiply", or use the slope parameters in SOPSAT.

NOTE: the above is strictly true in a linear system. But a multiplication by a constant is still a multiplication with a (different) constant after applying a pure power curve, like gamma - so the above is true in a (purely) gamma corrected system too.
Now, the 709 "gamma" curve is not strictly a power curve, it has a linear section near black, to avoid excessive noise amplification. But the difference is probably small enough to not cause problems here.
Video cameras might use additional non-power curves to manage dynamic range, in that case you might be forced to adjust lows mids and highs separately, or apply appropriate curves.

P.S. apropos the first link, "what good is a macbeth color checker"...
The author works for a competing firm, so obviously he has to conclude that it's worthless :-)
Admittedly, the colors on the checker do not correspond to the markings on a vectorscope, making them less useful when using one.
But still, since the colors are specified (the link contains a link to a pdf file with the numbers), you could use them for a check, or to achieve consistency across shots. In Kdenlive, you can use the Pr0be (under misc) to read out the values. Note that in the table, the RGB values are for sRGB, which, if I remember right, corresponds to rec 601 primaries (not sure about gamma). So if you are using 709, you should transform the table.

re sRGB, BT Rec709 primaries and transfer.

BT601 has no defined primaries of its own, its agnostic and dependant on lines of resolution whether that be SMPTE, EBU or Rec BT709.

Vylaren, doing these Primary corrections is good to know but really if time allows it would be better to do white balance adjustment in camera before shooting video or jpgs. Not so much a concern for raw as no WB is baked in then.

Secondary 'corrections' ie grading is something else.

Hello again!

My test with kdenlive, vectorscope and color chart, shows the project looks better now.

Now I am here (the second part of the article):
http://provideocoalition.com/aadams/story/cameras_rough_guide_to_color_grading_with_the_new_dsc_labs_oneshot/P2
when vectoreoscope lookticle)s close to the optimum, but not close enough.

My next question is, if there is a tool in kdenlive similair like Apple's this tool:
http://provideocoalition.com/images/uploads/OSC_Sat_Curve.jpg
so author of the article could move from here:
http://provideocoalition.com/images/uploads/OSC_Hue_Curve_VS.jpg
to here:
http://provideocoalition.com/images/uploads/OSC_Sat_Curve_VS.jpg

I am thinking about rather about Mg,Cy,Yl colors as for RGB thre is lots of tools in kdenlive.

The same tool:
http://rebelsguide.com/dl/sat.jpg
was used in this article - Save Our Skins:
http://prolost.com/blog/2008/3/23/save-our-skins.html


So I could easily boost just Cyan color:
http://provideocoalition.com/images/uploads/OSC_Hue_Curve_VS.jpg
Many thanks for all the answers so far.

The tool you mention seems to be a "hue dependent saturation adjustment"

It could be probably done with the new "Region" feature introduced in Kdenlive 094:

http://www.kdenlive.org/users/j-b-m/kdenlive-094-released#comment-20471

which should allow selective application of an effect, exactly what is needed for secondary color corrections.


The procedure would be: (but I could not get it working yet...)

1. use the color selection effect (under alpha manipulation), set selection subspace to HCI, and set delta G/B/Chroma and delta B/I/I to maximum (this way, your selection will only depend on hue). Then choose a hue you want to affect, and adjust delta R/A/Hue to set the range of hues that you want to affect. Increase Slope if you want a softer selection.

2. Add the Saturation effect (under Colour). Open it's effect menu (The "=" symbol left of the "X" delete effect in the upper right corner) and select "create region". ** Now here the problem arises - I could not find a way to use the clip's own alpha, I guess this will be added later?

3. Adjust the saturation - only the hues selected in step 1 should be affected.

==========================================================

In the mean time, you can work as described here:

http://www.kdenlive.org/forum/secondary-colour-correction#comment-19420