Outdoor Image tracking for AR

What is your experience with outdoor image tracking? If I understand it correctly you can only add one version of picture in the data asset? I though it would be smart to take pictures from different times of the day, that is different lighting, but since it says only one picture, I would like to know whether anyone have had issues with this or does it work fine in different lighting as long as this score thing is high enough?

No, that is unnecessary. Image tracking does not consider color. For iOS XCode would even complain that different images are to similar.