Calibrating Moving Lights

[Nick LX]

Hi,

On the ETC Ion, is it possible to calibrate the colours of two different types of moving lights so their CMY mixing produces as close to the same colour as possible? Is it done the same way as calibrate a scroller?

 

Cheers

[Ynot]

The principle is that each moving light of the same family should react exactly the same (within obvious tolerances) when sent the same DMX attributes. So regardless of the desk, if you send the same values of CMY to each fixture they should deliver the same output colour over all.

 

If the lanterns need calibration then this is a maintenance job - and should not be something needed as BAU.

[Bråthe]

Ynot, I think OP was asking about fixtures from different manufacturers or different models from same manufacturer. Your answering as if he was asking about 2 fixtures of same model that dont produce same color. Personally I have no knowledge about the Ion so I cant help. :blink:

[Ynot]

Fair point - yes - on re-read I do see that.

Although the theory should still hold that CMY mixing should be fairly close I'd say on different fixtures. Or at least on quality fixtures, anyway.

Having seen the palette mixing demonstrated on the ION, the desk will hold the personality, and thus the required values for mixing a specific colour. I seem to recall, for example, that you can specify a Lee colour within the palette s/w and relate that to the individual fixtures - the CMY wheels will then create that colour using the relevant values for that fixture. Tell the desk to set the colour mix to the same Lee number for a different fixture, and again it should send the necessary values to those - which shouldn't be a million miles away from the first.

I think you can also store a selected colour for comparison by picking that colour from the on screen colour circle and setting it aside for reference.

 

I'm sure an ETC expert will be along to confirm, but that's how I believe it works.

[timmeh2]

Hi

 

I'd have to say that the CMY values could be different both between fixtures of the same type, and more so across different fixtures. This is down to manufacturing tolerances in the filters (however tight) and the range of colour temperatures that you get from each source, be it tungsten or discharge.

 

The way to address this problem is matching the colours visually when creating your palettes. Remember that the DMX value just tells the fixture to move its stepper a certain distance from zero, and that wont translate into the exactly the same shade for every fixture you have. On units that have continuous rotation CMY wheels, like the MAC300, VL3000 and similar, zero is determined by the position of the magnet stuck to the side of the wheel. Whilst the tolerances are very tight, you can find differences in zero position that can be as much as +/- 2 steps, or worse if you're unlucky. On units that use mechanical stops on their filters like the Wybron Nexera, the difference can be even greater.

 

Hope this helps

 

All the best

Timmeh

[blackbird]

The Eos family desks all use the Carallon fixture library service, which is slowly becoming the industry standard, rather than every manufacturer writing their own library.

 

This service includes colour data, so assuming ETC purchase this set of data, which I assume they do given the console capabilities, they have the ability to match gels to CMY values, and choose comparable CMY values between two fixtures. If I remember rightly if you select multiple fixtures, then the colour picker will show you the common achievable portions of the colour spectrum - how correct this is I don't know, but at least it provides a starting point for tweaking.

[Tomo]

You cannot calibrate colour-mixing fixtures yourself - this requires a very expensive and longwinded process of colour measurement using specialised colour measuring equipment. (It isn't done by eye as there are too many variables.)

 

If both fixtures have calibrated personalities, then if you work in the "HSB" colour space both fixtures will match each other as closely as possible.

You can tell if a personality is calibrated by selecting it and looking at the colour picker:

 

If there is a black line running around the colour picker, then the personality is calibrated and the black line shows the 'colour gamut' of the fixture.

 

If there is no black line, then the personality is not calibrated and Eos/Ion/Element will make a 'guess' as to the correct CMY values to use.