Message
Re: Using a densitometer to make digital negative curves
2017-02-18 by sanking@...
I use both the 21 step wedge in the iOne folder that is included with QTR, and also the 51 step wedge.
Also use the 51 step wedge in the iOne folder, but for alternative printing you must have great control of process to linearize with the 51 step wedge. I find it much easier to do this with the densitometer than with a spectro since it is easy to see the values and adjust them slightly to get good increasing/decreasing values.
I use the Stouffer 21 step wedge only for analog testing, for digital work it is better to print negatives from the 21 or 51 step digital wedges where the steps are at increment of 5% or 2%.
I have used Richard's tool kit for smoothing multi-gray value QTR profiles for digital negatives and it worked great. Have not gotten around to using the spread sheet he suggests here for curves, but plan to.
One point that should be mentioned. The GRAY-CURVE= command applies to gray values, whereas LINEARIZE impacts all of the values. This may or may not be relevant to your work, but it should be mentioned.
Sandy