If your answer to that is 'never' (which would be perfectly reasonable), then look away now! I make no pretensions to being an artistic photographer, or even a particularly good one, unlike many of you. I see my photos as illustrative, to record a plant, animal, behaviour, habitat or scene that I might want to revisit, or to use for talks or courses - or now, for blogs!
My answer to the above question would be "when it's the only way to properly tell a story that I think is worth telling". Until the beginning of last year I lived on the other side of The Lake (in Canberra this is relevant) in a rented house with a very large garden - and had done so for 27 years. When it was finally time to set up home here with Lou, with a much smaller garden, one of the few things I regretted leaving behind was 'my' population of skinks in the garden. I was pretty sure the house would be sold and bulldozed for townhouses (it is very near the city and the university), so I seriously considered the unthinkable - catching some of the lizards and transferring them here. In the end I didn't, because while we were moving I discovered that we had our own skinks, in both front and back yards. I didn't need any persuasion that coming here was a Good Move, but that discovery seemed to be some sort of endorsement. For the record the skinks are Grass Skinks (Lampropholis delicata) widespread along the eastern coast and ranges, but not always found in Canberra suburbia.
Yesterday, for reasons that would be boring to relate, I was looking under the topmost of a small and unaesthetic pile of concrete roofing tiles tucked under a shrub out the front; they would have gone ages ago, but the skinks call them home. It was a miserable grey drizzly day but to my astonishment, under the flimsy shelter of the top tile were not only three skinks but a gecko! There are only two geckos in our part of the world, and both occur uncommonly in gardens, but generally only when alongside a reserve - we, sadly, are nowhere near one. Yet, here was this exquisite Marbled Gecko (Christinus marmoratus) doing us the inexpressible honour of living in our little yard! I raced in for the camera, and when I relifted the tile they were all still there, though by now burning precious energy reserves in waking up. I took three quick shots (still holding the tile in the other hand); with the dearth of light I was working at 1/8 of a second, and the flash chose to slip out to lunch at that point! (Needless to say it worked fine 5 minutes later inside.) I didn't want to harass them any more than necessary, and in any case the gecko then slipped away behind a plant container.
I was rapt, but the photos are rubbish. They do however record the special moment for me. Share it with me if you can bear it...