ISO on 70D When Using Flash

tspencer1 wrote in post #18467266
ISO 800 because when the camera defaults to ISO 400 on my flash shots, they have been coming out dark. f14 because at 1/200 shutter, that's what got me proper overall exposure - according to the settings before I popped up the flash.

i'd lower the ISO, and open the lens up a bit, don't let the camera choose everything for you...you're going to want to adjust the FEC on the onboard flash if you are shooting into the shadows like that...i'm not sure how well the onboard would work though in that situation.

Thanks Dre.

DreDaze wrote in post #18467312
i'd lower the ISO, and open the lens up a bit, don't let the camera choose everything for you...you're going to want to adjust the FEC on the onboard flash if you are shooting into the shadows like that...i'm not sure how well the onboard would work though in that situation.

He is probably at maximum flash power, and the flash is insufficient for filling daylight at that distance.

The shutter speed is the only camera variable that balances ambient and flash at full flash power (or any given flash power), and he is already at the shutter speed that gives the highest fill. It is a hopeless endeavor to compete with the sun from around 15 to 20 feet away with a pop-up camera flash.

I was thinking the same. Such tasks can be difficult enough with a 600 EX-RT on the camera...

Here's a similar picture I took, but I'm not sure you are helped with that? Can you see it? I try to make links to the image, but this forum seems to kill addresses that refer to google. At least this link I can follow myself, but I don't know if that's because I'm logged in or what. If you can't see it, let me know and I can perhaps PM a link.
Anyway, same kind of conditions (sun from behind), same kind of subject. 1/250 s, f/10, ISO 400, 42 mm focal length (camera is a full-frame, 1DX Mark II) and with that 600 EX-RT in the hot shoe. You can see what a more powerful flash can do.

DreDaze wrote in post #18467312
i'd lower the ISO, and open the lens up a bit,

But as far as the flash goes, that doesn't help. One f-stop larger implies one ISO stop less, and that's equivalent for the flash.

John Sheehy wrote in post #18467361
He is probably at maximum flash power, and the flash is insufficient for filling daylight at that distance.

The shutter speed is the only camera variable that balances ambient and flash at full flash power (or any given flash power), and he is already at the shutter speed that gives the highest fill. It is a hopeless endeavor to compete with the sun from around 15 to 20 feet away with a pop-up camera flash.

John - thanks. Yes, was at full. Point taken on the pop-up flash. Question - why is shutter speed the only variable that balances ambient and flash? Why wouldn't aperture do this also?

apersson850 wrote in post #18467434
I was thinking the same. Such tasks can be difficult enough with a 600 EX-RT on the camera...

Here's a similar picture I took, but I'm not sure you are helped with that? Can you see it? I try to make links to the image, but this forum seems to kill addresses that refer to google. At least this link I can follow myself, but I don't know if that's because I'm logged in or what. If you can't see it, let me know and I can perhaps PM a link.
Anyway, same kind of conditions (sun from behind), same kind of subject. 1/250 s, f/10, ISO 400, 42 mm focal length (camera is a full-frame, 1DX Mark II) and with that 600 EX-RT in the hot shoe. You can see what a more powerful flash can do.

Anders - I was able to view and yes - I see what a big difference that flash makes - thank you.

tspencer1 wrote in post #18467510
John - thanks. Yes, was at full. Point taken on the pop-up flash. Question - why is shutter speed the only variable that balances ambient and flash? Why wouldn't aperture do this also?

The sun and the flash exposure both have to pass through the same aperture. If you lowered the shutter speed, the flash would remain the same, but the sunlight would give more exposure, making things even worse. You can't increase the shutter speed with the builtin flash, and even if it had high-speed sync, the maximum flash power drops quickly as you increase the shutter speed.

If you were shooting in the dark with the flash as the only light, then aperture becomes a very important choice affecting maximum distance. It's one of the reasons your range is very small, true, but does not explain the ratio with the sunlight. Increasing the size of your aperture would blow out the sunlit areas at that same ISO, and if you lowered the ISO, then your range drops again.