Different tomatoes fluoresce differently under ultra violet light

In our small greenhouse my wife grows different varieties of tomatoes. Wandering around with the UV torch I saw that how they fluoresce differs with the variety and state of ripeness with the fully ripe fruit not fluorescing whether the ripe colour is red or yellow whereas the yellow unripe ones seem to fluoresce blue as do the green unripe ones. Strange…

What I am showing here are 3 varieties each with ripe and unripe fruit together on the stems. I will show 3 photos for each: daylight type lighting, UV fluorescent lighting and a composite of the two. First up is a large variety ‘Supersteak’:

‘Supersteak’ tomato, both ripe and unripe, illuminated by a daylight torch
‘Supersteak’ tomato, both ripe and unripe, illuminated by a UV torch

A composite image of the ‘Supersteak’ tomato, both ripe and unripe, showing both daylight and fluorescent versions

Note that in the above the green unripe tomato shows a bluish colour and the ripe ones are black (and tasty!). In this next set I show a small yellow variety ‘Sungold’:

‘Sungold’ tomato, both ripe and unripe, illuminated by a daylight torch
‘Sungold’ tomato, both ripe and unripe, illuminated by a UV torch

A composite image of the ‘Sungold’ tomato, both ripe and unripe, showing both daylight and fluorescent versions

As before, in the above photos the green unripe tomato shows a bluish colour and the yellow ripe ones are black. There isn’t a lot of difference in the visible colour of unripe and partially ripe fruit but the unripe shows blue and the partially ripe shows black. In the next set I show a small orange unlabelled variety:

Unlabelled tomato, both ripe and unripe, illuminated by a daylight torch
Unlabelled tomato, both ripe and unripe, illuminated by a UV torch

A composite image of the unlabelled tomato, both ripe and unripe, showing both daylight and fluorescent versions

In this third set of photos the green unripe tomato shows a brighter blue colour and the orange ripe ones and the yellow partially ripe ones are black.

This has been an interesting exercise one that I shall continue with.

Author: Paul L.G. Morris

I am an amateur photographer whose photography is mostly of gardens, nature and the rural environment. My specialities are close-ups, panoramic views, or a combination of both that I call 'Nearscapes'. I work mostly for my own interest having closed my business PM Studios Ltd.