Online Tool for curve plotting and analyzation

Bill Burk · Wednesday at 4:00 PM

reneboehmer said:
Or do you mean I should add a feature that allows users to derive luxs from a "perfect" ISO curve and then use this value as a reference for other plots? This to me sounds a bit dodgy. I would probably suggest measuring the actual exposure given by the sensitometer. As the other method introduces many points of uncertainty.

In a consistent sensitometer the exposure will be the same every time. So finding it once is good enough.

reneboehmer · Thursday at 12:33 PM

Small update.

-Ci is now illustrated with the arcs drawn.
-The XY grid steps are now user definable to make for more accurate manual reading of the curves
-The ISO triangle illustration appears as a tickable box once the mode ISO is used.
-A mode that will plot each curve separately in the exported file (It will always show Ci and Delta X illustrations in the single curve plots, like on my picture below.)

reneboehmer · Thursday at 1:14 PM

@Bill Burk
I added the sensitometer calibration for you. There is a small button under the ISO options. (more...) if pressed you can add a “golden curve” this will be used to calibrate the X axis to your sensitometer, with the method described by you earlier.

It does it like this:

It looks at your reference density data and finds its speed point (the exposure needed to get a density of 0.1 above base+fog).
It calculates the real exposure in lux-seconds that a film with that box speed should have required according to the official ISO formula.
It finds the difference between the real value and your sensitometer's value. This difference is your personal "log H offset." A confirmation message will appear showing you this calculated offset value.

From now on (until you clear it or refresh the page), the tool is calibrated.

The chart's x-axis label will change from "Relative log H" to "Calibrated log H (lux-s)".
The ISO values calculated for all your other curves will now be absolute ISO speeds based on this calibration.

Bill Burk · Thursday at 1:25 PM

Thanks!

reneboehmer · Thursday at 1:52 PM

Oh, and the tool will show some info here now instead of on the graph directly. That gets too convoluted.In this case, the user selected to see the ISO triangle. The tool will tell the user info about it.

reneboehmer · Thursday at 2:53 PM

Small Update:
-The export will now use JPG instead of PNG files, Pngs were getting to large in file size. The user can chose the JPG compression of the files with a slider.
-An area in the export document with citation of used literature

reneboehmer · 2025-09-06T08:28:59-0400

Update:
-The software will now not only interpolate from datasets but also extrapolate from the datasets. If you have too little data, the software will now output "recommended" times and speeds based on second degree polynomial equations. The data that will be "found" this way will be in displayed as Italic in the datasheet PDF. (This is information is not within your own data reach, and is therefore to be taken with a grain of salt. For small overreach it should be ok, but larger gaps should be filled by actual data.)
-A Delta X / Fixed density bug has been fixed. It now again works as intended.
-ISO parts have been renamed to EFS effective film speed

Online Tool for curve plotting and analyzation

Bill Burk

reneboehmer

reneboehmer

Bill Burk

reneboehmer

reneboehmer

reneboehmer

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