# Manual color calibration - again
**URL:** https://discourse.psychopy.org/t/manual-color-calibration-again/4535
**Category:** Other
**Created:** [May 18, 2018, 9:15pm UTC](https://discourse.psychopy.org/t/manual-color-calibration-again/4535 "2018-05-18T21:15:22Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Bill\_Prinzmetal](https://discourse.psychopy.org/u/Bill_Prinzmetal)
#### Post date: [May 18, 2018, 9:15pm UTC](https://discourse.psychopy.org/t/manual-color-calibration-again/4535/1 "2018-05-18T21:15:22Z")
I apologize in advance, this question has been asked before. I have looked up every posting I could find. I borrowed a minolta CS100 monitor and took 9 measurements for each R, G, B, all. In 2 posts Jon suggested using:
myfit = psychopy.monitors.GammaCalculator(inputs=[], lums=[])
print myfit.params
So this is what i tried:
from psychopy import visual, monitors
inputs=[0,32,64,96,128,160,192,224,255] # values of R
lums=[0.773, 1.002, 1.863, 3.566, 6.347, 10.31,15.52,22.13,29.82] #cd/m^2
myfit = psychopy.monitors.GammaCalculator(inputs, lums)
The only thing it will print is gamma, and its the same as if I put in:
---
### Author:  [@Bill\_Prinzmetal](https://discourse.psychopy.org/u/Bill_Prinzmetal)
#### Post date: [May 18, 2018, 10:12pm UTC](https://discourse.psychopy.org/t/manual-color-calibration-again/4535/2 "2018-05-18T22:12:42Z")
sorry hit wrong button.
myfit = psychopy.monitors.GammaCalculator(inputs, lums, eq=1) #Give back only the one parameter, g
myfit = psychopy.monitors.GammaCalculator(inputs, lums, eq=2) #Gives g, but its different
myfit = psychopy.monitors.GammaCalculator(inputs, lums, eq=3) #error
myfit = psychopy.monitors.GammaCalculator(inputs, lums, eq=4) #returns all 4 parameters but the formula still says easy. Just look at red.
I have tried to fit it with excel but I get different parameters. I’d like to be more sure of that I was doing. I am not even positive that I am interpreting the formulas correctly. I was assuming that
a + kx^g was a+ (k\*(x^g)), but I see a lot of different things when I look at the code. It would be nice to have a “cookbook” on entering ones own calibration. The photometer I borrowed is out of production and I don’t think it has a serial input.