Longtudinal chromatic aberration and light sources

I was checking my Nikon 70-210mm F/4 series E and my Nikon 85mm f/1.4 D shooting a white paper strip with ruler markings to get a sense of the level of longitudinal chromatic aberration and while it was (sigh) very easy to see the red/cyan fringes when the light source was an incandescent light bulb with a metal reflector, there was none when using a flash. Both lenses were tested fully open and at the same (approximately) 85mm focal length.
I guess this has to do with the wavelength spectrums of the two light sources?

It was heartwarming to see the SB800 teach the lenses what appropriate optical behavior is about.
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Best Regards,
Renato

'The world is going to pieces and people like Adams and Weston are photographing rocks.' Henri Cartier Bresson, in the 1930's