To this end, a study was set up to determine the exact location where the two photos were taken. By combining visible elements in the photos with historical aerial photographs, drone imagery and spatial analysis, it may be possible to reconstruct where the grave is located.

The main research question is:

Where were these photos taken?

In addition, the study examined:

• Whether both photos were taken at the same location
• Whether both photos were taken at the same moment

Photo 1

Photo 2

To determine where the photos were taken, reference points are needed. Both photos show various landscape features that can be used for this purpose.

These features were identified so that they could later be placed on a historical aerial photograph and serve as spatial reference points.

Which recognisable features are visible in the photos?

The following features could be distinguished:

• Trees (maritime pines): light green
• Barrack: red
• The mortuary (read the blog post about it): yellow
• Firing range berm: pink
  • Front of the low berm: light blue
  • Dark patches in the berm: purple

Photo 1 annotated

Photo 2 annotated

The visible elements in the two photographs

Because photo 1 contains several recognisable elements that can serve as reference points, it was decided to determine its location using an angle analysis. This involves identifying specific points in the photograph and translating them to their positions on the map.

The photograph was taken from a viewpoint that meets the following conditions:

1. The second barrack is visible
2. The mortuary is visible
3. The front of the low berm is visible
4. The tree with the distinctive branch is located just to the left of the low berm
5. The inner corner of the high berm is visible

When these features are marked on the photo, a spatial relationship emerges between the reference points. This leads to an important geometric condition:

The angle between the centre point and the left point must be equal to the angle between the centre point and the right point.

Reference points photo 1

Initial test locations
Using this method, potential camera positions were first examined in the area around the former Kiesgrube.

From these locations, the angles between the reference points were calculated. Although the position of the tree with the distinctive branch relative to the low berm initially appeared to match, the difference between the calculated angles was consistently substantial. As a result, the geometric relationship between the reference points did not match the situation in the photograph.

These locations could therefore be ruled out as unlikely.

Alternative locations
Next, positions closer to the firing range berm were examined.

From these locations, the angles between the reference points corresponded much more closely. In several cases, the difference between the calculated angles was very small. In addition, from these positions the relative position of the tree with the distinctive branch matched what is visible in the photograph: just to the left or just behind the low berm.

This indicates that these locations align more closely with the original viewing direction of photo 1.

Most likely location
The locations where the difference between the calculated angles is minimal form a cluster of possible camera positions.

This area can therefore be considered the most likely location from which photo 1 was taken.

This location can then be tested using the same method as for photo 1. When the angles between the reference points are calculated from this position, the difference between the angles turns out to be considerably larger.

This suggests that the viewing direction of photo 2 differs from that of photo 1.

This supports the possibility that:

• The photos were not taken from exactly the same position

Or:

• A camera lens was used that makes the berm appear closer than it actually is

Both explanations are consistent with the visual features of photo 2.

Based on the analysis, it seems quite possible that the two photos were not taken from exactly the same location. It is, however, likely that both images were taken within Kamp Amersfoort.
In addition, the possible use of a camera lens that optically brings objects closer should be taken into account. This could make the high berm appear closer than it actually was, which may affect the interpretation of the viewing direction.

It is likely that both photos were taken at the same moment, as at least two people wearing the same clothing can be recognised in both images.

It is possible that other people in both photos are also the same individuals, although this cannot be established with complete certainty.

The comparison below shows cropped sections of each person from both photos.

Person 1

Person 2

Based on the angle analysis, a range of possible camera positions for photo 1 could be examined. The differences in angles between the left, centre, and right points provide insight into how well a location matches the viewing direction shown in the photograph.

The most likely location lies within the cluster of points where the difference between the calculated angles is only about one degree.

By combining these locations, a defined area could be established that best corresponds to the geometry of photo 1. This area therefore represents the most plausible zone from which the photograph was taken.

It also remains possible that photo 1 and photo 2 were not taken from exactly the same location, or that a camera lens was used that visually reduces distances. However, it seems likely that both photographs were taken at roughly the same moment.

This analysis demonstrates how spatial methods can contribute to historical research. By combining historical photographs with map data and GIS analysis, it is possible to reconstruct a location in a well-founded way, even when the available sources are limited or incomplete.