In the diagram below I have highlighted possible measures of SP-D images (AFM) which might shed some light on how many peaks are in the LUT tables, most particularly in the collagen like domain. It is obvious that the CRD and the N terminal junction of two trimers that make up one set of arms of the dodecamer are easily seen and not that variable (with the exception of the lumpy character of the CRD which sometimes shows a smaller peak in the luminance on the LUT tables.

1. pixels (area) beneath the curves (separated from each other at the side of the value for the lowest valley (which almost always ends up on the outside (lateral) edges of each peak
2. distance in nm of each peak (100 nanometers on the x axis)
3. peak height from 0 on the luminance (1-256 on the y axis)
4. peak height from the lowest valley on each individual portion of the LUT tables
5. hand counting peaks (in this case 9 total with two of the peaks showing a tiny sub peak) but 3 on each of the collagen like domains and one in the center (N terminal juncture between two SP-D trimers) and a CRD on each outside end.

The typical number of peaks in any dimer-arm (two trimers end to end at N terminals) is measured at 100 nm and equals 9 i believe.