# AutoISO with flash



## Evirc (Dec 10, 2013)

Hi guys!
I have a problem with my Canon, that I noticed also on other cameras like mine.
When the flash is connected to the hot shoe and the iso mode is set on AUTOISO, ISO remain fixed at 400 in both AV and M mode... anyway, in TV mode the ISO settings seem to work correctly.

If I take a photo during a ceremony, for example, I don't have time to waste in changing ISO settings... considering the price of the camera I thought there could be a sort of assistance in choosing ISO settings even when the flash is on...   
Is there a way to solve this snag?
I heard about Magic Lantern, but it's still reserved to developers...


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## EIngerson (Dec 10, 2013)

I'm not sure why you would want to use auto ISO with flash photography. You should try to stabilize your exposure as much as possible. Are you indoors? outdoors? what are the conditions? You shouldn't have to change ISO very often at all. Only when you change your environment.


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## Braineack (Dec 10, 2013)

which exact model do you have?  AutoISO when flash is in use would really be a hindrance in a lot of situations.


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## Evirc (Dec 10, 2013)

EIngerson@ You are right, but generally, during weddings, light conditions change  quickly... it depends on the situation and I don't wanna miss a single  moment.

Braineack@ I have a Canon 6D with 430exII.


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## Braineack (Dec 10, 2013)

But from a quick search (I know little about canons) sounds like this is normal unless you shoot in P mode or turn autoiso off.

I wonder what happens if you take the flash off ETTL?


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## Evirc (Dec 10, 2013)

if i connected a manual flash (i have a yognuo 560II) the auto iso work fine, but the exposure became very difficult...
I don't know how other photographers face this problem...


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## Braineack (Dec 10, 2013)

they most likely all shoot manual flash in the first place and just know how to compensate.


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## KmH (Dec 10, 2013)

The camera uses ISO 400 to minimize the possibility the flash unit has to fire at full power. Not firing at full power provides a faster recycle time for the flash unit.


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## kundalini (Dec 10, 2013)

Often a seemingly insignificant setting change can wreak havoc on future shooting, especially when it is forgotten.  Reset your camera to factory default and try again.


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## Evirc (Dec 10, 2013)

ok KmH, but i need 1600iso in low light, if i set auto iso with a flash connected the iso is fixed, and the shutter speed became to much slow in AV


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## KmH (Dec 10, 2013)

Then what you need is a flash unit more powerful than the 430 EX II.
With the flash you should not need ISO 1600.

However, you don't say what flash head zoom setting you usually use. The 430 EX II's GN (guide number) specification is adjusted for a flash head zoom setting of 105 mm, it's maximum zoom.


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## Evirc (Dec 10, 2013)

No... the flash can't light up the background...but the high iso is the solution 
I use the flash only fill ligh, not as main light... So the light is more natural


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## toughsamurai (Dec 10, 2013)

What lens are you using, use the low f stop such as 1.2, 1.4 etc. this allow you to reduce your ISO.


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## EIngerson (Dec 10, 2013)

Evirc, there's a lot of good photographers telling you pretty much the same thing. You can control your environment with aperture and shutter speed, while keeping a set ISO with a flash. I'm not sure what else to say.


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## amolitor (Dec 10, 2013)

Auto ISO with TTL flash is an interesting idea. I'm not sure that any of the TTL systems actually adjust camera settings to match the flash output, however. TTL flash generally is used to calculate how much power the flash should pump out -- given the current state of the camera settings, as I understand it. So the system is nailing down the camera settings. There's no particular reason,  I suppose, that the camera settings (aperture, ISO) could not be adjusted as well, but I do not think that is how the systems work.

If you're using the flash only as fill, it's not clear to me what you want AutoISO to even do..


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## Evirc (Dec 10, 2013)

amolitor@ i set autoiso for achieve an perfect light enviroment quickly...
toughsamurai@ I need a flash for lighten the shadow

example:
AV mode
f/4
1/80s
Flash on TTL
ISO?

if the iso is auto the enviroment light is ever perfect, and the shutter speed isn't too much slow.


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## amolitor (Dec 10, 2013)

Yes, but what procedure should the camera use?

I realize the goal is 'it should make my picture awesome' but what should be metered when, and how should that be applied to the ISO?


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## Evirc (Dec 11, 2013)

it is simple ...
Now the shutter speed of the camera tends to be very slow, if you could set a minimum shutter speed, the image would be underexposed, but if the ISO would increase?
in TV mode, this function is correct but in AV mode and M is incorrect


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## amolitor (Dec 11, 2013)

Well, ok then.


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## EIngerson (Dec 11, 2013)

I'm out.


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## Evirc (Dec 11, 2013)

Why?
I'm sorry for my bad english


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## amolitor (Dec 11, 2013)

It's ok, I can't tell if it's poor english or if you're just not thinking it through fully, or some combination. It doesn't matter, though! It's not a big deal, right?


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