Looking for somewhere different to photograph the test train, I settled on Crowthorne with its 19th Century station building and distinctive platform canopy but hadn't realised that half the platform lights didn't work. Fortunately there was just enough light to capture an image of 73964 passing through with 1Q54, the 12:55 Eastleigh to Tonbridge test train, top'n'tail with 73965.
PHOTO DATA FOR IMAGE 24-D-0413
camera : Nikon Z6ii
lens : 24-70mm f/2.8
focal length : 60.0 mm
shutter : 1/400 sec
aperture : f/4.0
ISO : 4000 ISO
original : Digital: 24MP NEF
SUBJECT DATA
Loco / Unit : 73.964 top n tail with 73.965
Train : 1Q54, 12:55 Eastleigh East Yard - Tonbridge West Yard test train