Hi
konnichiwa usagi-sama, gokuro sama deshita ...
doumo arigatou gozaimashita. Sumimasen deskedou, mou sukoshi shitsumon arimasu, .
interesting, thank you for posting that data.
I use epson 3200 flatbet scanner with vuescan as an densitometer.
I simply scanned the stouffer step tablet and then checked what values vuescan's densitometer function gave. From these two values I created correction table and diagram.
Firstly, I assume that you did not have any applied gamma in the vuescan operation.
Was any area more or less linear (if the actual data was there on the graph as well as the trend line it would be valuable too).
I understand that all instruments require calibration (including any calibration reference instruments), so I am hardly surprised that a non scientific consumer oriented instrument is 'out'
I simply scanned the stouffer step tablet and then checked what values vuescan's densitometer function gave. From these two values I created correction table and diagram.
There seems more data points than the amount for a stouffer step tablet, I assumed that your software 'smoothed' the curve as the appearance of Poly suggests as a data set in the graph and that sample data is not presented. How did you determine the (apparently log) values for the scanner output data?
As for epson 3200, the more density increases, the more epson's reading will be off.
The attachment has example of my correction curve. As you can see, scanner's output is far from linear.
so was this reflectance density (effectively measuring the print) or transmission density (measuring the negative)?
thanks for your time.
btw, I visited your gallery, and I liked your many images of Japan. I would be interested to know if you were using 120 roll type cameras or sheet film camera?