It's practically impossible to tell, but as I am procrastinating I will take a shot (ho ho):
Telephoto of a minimum 200mm - reason: It's a kite surfer. There are ways of getting this close without a tele, but they aren't exactly simple, and would mean you'd have to be very good indeed at accurate panning - imagine how fast she's going there. Also, the perspective looks wrong for a shorter lens. Hard to tell definitively from an image with just sea in the background, but it looks compressed to me. however it's not that compressed, so probably not as high as 400mm.
Pretty small aperture, maybe f/16 - reason: It's obviously a very bright day, and given my assumption that it's a tele, the DOF is very much greater than you would expect for a wide aperture. My 210mm has DOF way lower than this even at f/4.
I agree the shutter speed is high to freeze the water droplets like that, so yeah, 1/500s.
ISO - no idea, because it does seems to have some post processing on the colours to me. I'd go 200 because it's a good default ISO for bright conditions.
Post processing - looks like a slight vintage colour filter, and that vignette has a very "added later" feel to me.
Re: your assumptions, I see no way for a shot in the middle of a sunny sea to have an aperture of 1.4 or f/2 and a shutter speed of 1/500s.
Look at the Sunny 16 rule; you would expect f/16, ISO200, 1/200s. So to get ~1/500th to freeze the water droplets, you want ISO400 and f/16, or ISO200 and f/11.
Those are the sort of base settings I'd be imagining this picture to be taken around.
Getting to f2:
Just for absolute clarity, here is a staged list of settings to get from Sunny 16 to an exposure using f/2 as the aperture.
- f16 - ISO200 - 1/200s
- f11 - ISO200 - 1/400s
- f8 - ISO200 - 1/800s
- f5.6 - ISO200 - 1/1600s
- f4 - ISO200 - 1/3200s
- f2.8 - ISO200 - 1/6400s
- f2 - ISO200 - 1/12800s
I'm not aware of a camera that has a shutter speed that high, but by going to ISO100 you could get 1/6400s (supported by the 5D at least), or if you camera has the increasingly rare ISO50, you could get 1/3200, supported even by my a55.
So, it's just about possible, but for the fact that a) I can see a very small amount of motion blur in the droplets, and b) the other reasons above, I don't think it's very likely.
You could of course get to f/2 with a sensible shutter speed using an ND filter.
UPDATE - calculated analysis:
I'm going to assume a lens of 200mm. That just feels right with the perspective, and I have to assume something.
First we need to know subject distance:
Distance = Lens focal length (mm) x Object Size (mm), divided by Image Size (mm)
Distance = (200 x 1620mm^) / 13mm^^ ~= 25000mm = ~80ft
^ Halfway between average Australian and average American women's heights. Hey, I had to pick somewhere, and they were the surfiest countries I could think of.
^^ Based on an APS-C sensor's height of 20mm (from the linked Canon blog) and the fact that she looks like she'd fill about 2/3rds the sensor at full height.
Plugging 80ft into this DOF calculator and given the focus extends for what, 5 - 10 feet? Hard to tell with the compressed perspective. Anyway that gives an aperture around f/4 to f/5.6.
So, quite a bit more wide open than I thought; looks like I need to shoot with the 200mm more to get used to it.
Presumably all these answers show that there are many ways to achieve a shot :o)