Originally Posted by

**AndreasT**
May I go back to the Delta X Criteion paper. Being confused as ever, reading and re-reading. (Having a headache)

I have now various curve for various films. To use the DeltaX I take the curve where the ISO triangle matches most closely and basically subtract the Delta X value. Being 0.296

Next I take the rest of the curve measure using the same ISO triangle length 1.30 log-H but with the higher Delta which touches the curve to find my Delta X Criterion from the table.

This will then show all speed point for the different curve.