At what sort of light levels?
Worst case, UK 100% thick cloud cover working under tree foliage with subject within vegetation with some of the vegetation above the subject, soon after dawn when light levels are still quite low.
I use very small apertures to get the most depth of field I can. This often leads to combinations of high ISO and slow shutter speeds. For example I quite often use (with ISO 800 or higher) exposures of longer than 1/10 sec, even with subjects that are moving a bit, like early morning slugs and snails for example, or subjects on leaves that are moving in the breeze.
I use a hybrid "hands-on tripod support" technique (with a strange, jointed-arm tripod) to (somewhat) damp down camera movements and to hold the composition/framing (somewhat) steady. Unless the conditions are optimal (e.g. post-dawn still air and a stationary subject, in which case I use a pure tripod, hands-off, remote shutter approach) I have a high failure rate and take many shots. Higher ISO shots can also need slightly more careful/more complicated post processing.
I do use flash sometimes, and perhaps not often enough, but that has its own mix of benefits and disbenefits. Whether I use flash or not depends on the ambient conditions of light and air movement, subject placement, size and movement, and my mood.
Are you using over ISO 400 in good lighting conditions?
In general, no. Occasionally, yes, when I need a faster shutter speed.
It's like
David just said:
"You use what you need. Simple as that... but you always use the lowest ISO you can.. unless
noise is is actually desirable for effect." (which it isn't for my stuff)
For me though, my preference for deep dof using available light determines what ISO/shutter speed combinations are available to me.
)
