In an earlier paper Morgan applied an image processing technique that is used in analyzing geographic photos to an ultraviolet (uv) photo of the Shroud of Turin taken by Vern Miller in 1978. The technique involved principal component analysis, and it was found that the first principal component explained 97.41% of the variance in the Shroud photo. When the first principal component was calculated for the radiocarbon test regions used to date the Shroud it was found that these regions were different compared to those of a typical region of the Shroud. The radiocarbon test regions were concluded to be statistically different from the main regions of the Shroud, suggesting that the radiocarbon dating may be invalid. In this paper it is shown that the first principal component is very highly correlated with the image intensity of uv Shroud photos. Using image intensity this paper re-examines the approach by Morgan and demonstrates that the variation in the first principal component could be due to the way the Shroud was illuminated, since Miller took his photo using non-uniform lighting. Regions away from the center of the uv photo, such as the radiocarbon test area, did not receive the same uv intensity as those near the middle, and as a result their reflected intensity would be smaller. By contrast when geographic photos are taken uniform illumination is provided by the Sun. Since Morgan’s technique assumes uniform illumination his statistical conclusions can be questioned. One color photo taken by Vern Miller under uniform illumination is also examined. Applying Morgan’s approach to the color photo indicates that the radiocarbon test region may be anomalous. Additional research can help clarify this question.