Hello, i'm looking over the Astera Titan fixture profiles and i notice that the CCT parameter is 0-255 and there's no way to reference actual Color Temperature. Working in film production its really important to be able to do this. For example the ARRI S60 profiles all reference CCT accurately, so this function would be really helpful. I could build my own and replace the displayed values with the correct range, but i'm weary that they will match up. i will try this tomorrow, check with a color meter, and report back. but as i understand CCT, it is logarithmic and non-linear so i think matching values wont work. The Astera app control has full CCT parameters that are accurate. so they have the capability.
The same goes for the other Astera fixtures i work with: AX3/AX5
As a gaffer and low level programmer i know that the first thing a Gaffer is going to want to see across ALL of the fixtures on set is accurate, predictable, repeatable CCT.
Would you be able to point me to the specific Astera profile you were discussing above and the manual for said fixture? I'd like to submit a profile update to the Eos team if this fixture profile is missing labeling that it should have. Thank you!
Hi Teresa, thank you so much for responding to me so quickly. here are the links to the manuals for the three different fixtures I'm working with. They are all made by astera. When I pull up the color temperature control in the moving light window and move it from minimum to maximum the values are 0 to 255.
I put a Kelvin color meter on the fixture through the range of 0 to 255, and I got to color temperature of 1800k at the low end and 4000 k at the max. Which is way off. If you use the fixtures control app you get a range of 2500 to 6500, which the ETC profile should match.
So not only are the values unreferenceable, they don't match the actual range of the fixture.
On each of the pages if you scroll down there's a downloads tab you open that and there's a manual link inside of it. Sorry there is no direct link to the manual that I can pull up on my phone.
Great! I am testing these profiles out now. Do you happen to know if this issue is present across all modes of these profiles? If not, I will need to know what modes you are using when seeing this issue. Trying to recreate the problem on my end currently.
the DMX charts show this (screenshot from AX3 manual):
according to that the color temperature range should be 2000K to 7100K. if the fixtures don't match this in real life that's one thing, but i think we should label the CCT range in the personality. it's linear after all so should be simple enough. UserMin 2000, UserMax 7100
they are persistent through all modes that have CCT parameters. all 3 lights cap at 4000k instead of 6500. and the FP1 Titan goes off the scale on the warmer/lower end of the Kelvin range.
also, the ax3 and ax5 have a color mix parameter that is confusing. depending on the postion of Saturation, Color Mix, and Color Temp, they behave differently.
correct but that is not how the parameter behaves on the fixture. when i run the CCT handle up and down on the ax3, at 4 points it goes to 2000k, which is correct, but at 255 it caps at 4000k. it does override the RGB at 4 as stated, but i cant get the color temp any higher.
and the color mix parameter is perplexing to me unless i turn it off
So I am submitting the request for label changes on this parameter to adhere to the CCT formula described in the fixtures' manual. If the formula in the manual is correct, the lowest color temperature should appear as 2000k and the highest as 7100. If the fixture is not outputting these values at the high/low temperatures you may want to contact the manufacturer and inquire about any inconsistencies between your fixtures and the manual.
thank you. i'll try to build a fixture in teh meantime see what happens.
can you explain what the Color Mix parameter is supposed to do? it doesnt appear to be a crossfade between RGB and CCT. so i leave it off.
the manual says that this is supposed to be a Lee filter library. unfortunately the profile is missing the list of gels.
Therese maybe we can get this corrected as well? the full list is here http://www.astera-led.com/Downloads/manual/AX3%20Manual%20%28EN%29.pdf on printed pages 41-44.
the FP1 has a gel menu that look accurate, the ax3 and ax5 have the color mix and no gel.
Thank you Ueli! I will add this to the fixture profile update submission.
i figured it out. i had a nonlinear dimmer curve applied in the fixture config. switched to linear and CCT checks out!!
furthermore i loaded your profile and changed the labeling, saved it and the numbers match up between the display and my color meter, so i am color accurate. since CCT doesnt activate until DMX is at 4, i set the user vale for DMX 1-4 at 1999, and the color temp range from 2000-7100 for reference. i'm assuming this is the way to do it sice you cant gap out the user values?
thanks for everything, i think once you change the labels for the next round it should all check out.
Yes, this would be the recommended fix until the profile can be reworked to add the info you had suggested!