So, do please tell me: in what real-world shooting situation would you want a shutter speed two stops slower (ISO 100 => ISO 25) that you can't reasonably stop down an additional two stops (f/4 => f/8) where you wouldn't already need significant ND filters in the first place?
For effect, the aperture is kept as open as possible ... accentuate the subject, blur the background ... and not necessarily people ... but road signs, trains, etc.
Sunny-16 rule ... ISO 100, f/16, 1
... thus ISO 100, f/2.8, 1
Now, I'm not really complaining, because my 30D's can do 1
. But seeing as there is a trend with Canon on reducing the maximum shutter speed down to 1
, it means I'm already shooting at the limit ... and this reduces the flexibility of a DSLR over an FSLR ...
Photographing an aircraft where I want the background blurred, as well as the propeller, requires a wide aperture and a slow shutter speed. ND filters work, but as I've said, they're a hassle ... especially when the subjects (and hence shooting conditions) change rapidly ... remove hood, remove ND filter, put ND filter in pouch, replace hood, put pouch in pocket ... see same type of shot ... redo in reverse ... miss shot ... swear ... get fingerprint smudge on filter ... swear again ... ... as opposed to press button ... adjust ISO ... shoot.