[tripodquest]

I'm not a math genius or an electrician so I figured I'd ask smarter people.

From Wikipedia I read that EV100 (EV at ISO 100) for overcast bright is 13 and heavy overcast with shadows is 12, and that 13 corresponds to a shutterspeed of 1/8000, 1/4000 and 1/2000 at f/1, f/1.4 and f/2 and 12 half of that.

I'm trying to figure out the EV for my constant lighting setup because I'm interested in taking photos at shutter speeds of 1/1000-1/8000 indoors at a reasonably LOW ISO (low ISO is 400 max, preferrably closer to 100).
Using a large aperture (f/1.2 - f/2) is no problem (prefocusing/focus trap is always a possibility) so I think not too many lumens would be needed?

I will have 15,000 lumens from one lamp (3 lights in one fixture), how much is this enough for? Aluminum foil is cheap and can reflect it on whatever surface area so light lost should not be a problem.
What about using 30,000, 45,000 or 90,000 lumens?

How much do I need to get decent shutter speeds of 1/2000 - 1/8000? I can rig 50,000 lumens of constant light for $140, if you know a flash Pentax supports that can sync up to 1/8000 for around that then you can recommend it, otherwise I'm not asking about flashes.

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Last edited by tripodquest; 11-10-2013 at 06:38 PM.

[SpecialK]

Can you not simply take a test photo and calculate the light requirements from there?

[maxfield_photo]

Can you not simply take a test photo and calculate the light requirements from there?

I would add a $5 18% gray card to this suggestion, but otherwise, yeah. If you can fill your frame with the gray card (without casting a shadow on it), your exposure is guaranteed to be correct. Then just remove the gray card from the scene, but keep the same exposure settings. If you can't get close enough to the card, hopefully your camera has a spot metering mode, that will work equally well.