While hiking with Shuwen at Torrey Pines Extension to show her the Delphinium cardinale (Scarlet Larkspur) in bloom, I remembered a technique I had not used in a long time – “killing the ambient light” with a fast shutter speed and a small aperture (high f-stop number) and then use flash to illuminate (and thus, isolate) the foreground subject.
The results aren’t perfect because I didn’t have a dedicated flash with me so I used the on-camera flash (off camera from an angle would be far more desirable of course). In hindsight, I should’ve lowered the ISO and let the little flash work harder because you can still see some background (it was afternoon and still quite bright) … but I didn’t want to fiddle around too much, since there was nice light waiting for us further up on the trail. :-)
Depth of field is another issue – you just don’t get the nice isolation of foreground flowers when you stop down so much. On the one hand, I think it’s a technique that is worth playing with, on the other hand I’d have to bring a separate flash unit (and remote trigger or cable), quite possibly light stand, and then I might as well haul the tripod – and that’s just too much gear for the “lightweight & relaxed” approach to my wildflower photos.
The Silene laciniata (Indian Pink) by comparison is in a wooded area (in the Scrub Oak chaparral of the Del Mar Mesa Preserve) and was illuminated by natural sunlight that was lighting up just this flower. That was really neat, but chances to find something like this when you need it are rather slim I’d say, so it’s not something I’d be looking for typically. :-) It worked out quite nicely in this case, because I also underexposed to preserve the red channel (more notes about photographing and processing intensive reds in the link to the Delphinium cardinale, above).