I think im still not understanding how my flash works

[Robin Usagani]

So I was taking a photo of my daughter a few minutes ago. I used manual, pretty high ISO and I used manual flash at 1/128 power. On my preview it looked too bright for my taste. Then I changed the flash to E-TTL and kept the same shutter, aperture and ISO and the result was good. How come the ETTL can set the flash power lower than 1/128 power but I cant do it manually? 1/128 is as low I can go.

 

[Light Artisan]

First questions I have is why the high ISO with flash, and what aperture are you using?

1/128th is not a lot of juice, something isn't right there, but you don't mention which flash you're using.

 

[ababysean]

I'm playing with my flash off camera too.
I'm using commander mode but I don't like how I have to use it TTL? oh wait, I think I can change it.
From what I understand is you want to use a lower ISO when you use flash because there are really two exposures when you use flash and the first one uses your ap. and your ISO, the shutter speed is almost pointless, you set that close to your sync and forget it.

 

[Robin Usagani]

Doesnt matter what the the ISO is.. Im just saying why I cant go lower than 1/128 when ETTL obviously shot it at lower power than that.

 

[Light Artisan]

You still haven't said what flash you're using - and yes, ISO does matter. I guess we have to read your signature to get information and assume it's the 550EX?

Shutter speed is never almost pointless. ISO, Shutter Speed and Aperture play the same roll with or without flash.

Flash photography is too much to sum up in one post, there are books dedicated to it.

 

[table1349]

So I was taking a photo of my daughter a few minutes ago. I used manual, pretty high ISO and I used manual flash at 1/128 power. On my preview it looked too bright for my taste. Then I changed the flash to E-TTL and kept the same shutter, aperture and ISO and the result was good. How come the ETTL can set the flash power lower than 1/128 power but I cant do it manually? 1/128 is as low I can go.

Basic answer to your question, the camera and flash are communicating with each other to produce the shot at set parameters. This communication provides a range of maximum power down as it sees fit.

You are not communicating with the flash. You are imputing designed parameters, full power, half power, 1/4 power etc. It would be excessively costly to put and external control for a human to dial up any power setting. That is what a light meter is for. Set two of the three parameters of the exposure triangle and it calculates the third parameter to get a proper exposure.

 

[kundalini]

Doesnt matter what the the ISO is...

WRONG! and FAIL!

 

[Light Artisan]

That's not true... in manual flash mode you do control everything, you can nuke the sun if you want to.

I'm not up on Canon flash units so I can't help explain how to set the flash to less power, nor could I find a manual on Canon's site a few minutes ago to look it up.

 

[Robin Usagani]

Ok so the short answer is ETTL can shoot at lower power than 1/128? I just thought 1/128 is the lowest ETTL can shoot as well.

 

[Robin Usagani]

Doesnt matter what the the ISO is...

WRONG! and FAIL!

OMG.. you really twisted my tounge. This is ridiculous. All I was saying is.. I have my ISO, shutter and aperture at the same setting. I shooot one with manual flash at 1/128, and one with ETTL. The ETTL give me power lower thatn 1/128 which I thought was not possible.

Yes I know ISO affects the exposure.

You FAILED reading my question kundalini

 

[Light Artisan]

Short answer, lower your ISO.

 

[Robin Usagani]

Short answer, lower your ISO.

WOW... Maybe you should learn about ISO. What if I want more ambient light at a wedding? You missed my question just like kundalini did.

 

[kundalini]

You FAILED reading my question kundalini

You failed to make a correct statement. ISO does have an effect. You should know that by now. Think about all the newbies that could have read that comment as fact.

 

[Overread]

Guys read the question and lets stop with the cheapshots at each other


pretty please :hugs:

So I was taking a photo of my daughter a few minutes ago. I used manual, pretty high ISO and I used manual flash at 1/128 power. On my preview it looked too bright for my taste. Then I changed the flash to E-TTL and kept the same shutter, aperture and ISO and the result was good. How come the ETTL can set the flash power lower than 1/128 power but I cant do it manually? 1/128 is as low I can go.

Basic answer to your question, the camera and flash are communicating with each other to produce the shot at set parameters. This communication provides a range of maximum power down as it sees fit.

You are not communicating with the flash. You are imputing designed parameters, full power, half power, 1/4 power etc. It would be excessively costly to put and external control for a human to dial up any power setting. That is what a light meter is for. Set two of the three parameters of the exposure triangle and it calculates the third parameter to get a proper exposure.

Hmm this is interesting since using flash manually is often quoted as "the" way to shoot flash; yet here you say what I've guessed, but never had confirmed, that the flash in ettl can select different powers to those that the photographer can in manual mode. (which goes some way to explaining why flash power output isn't recorded in EXIF data -least to my understanding).

 

[Robin Usagani]

Thanks gryphonslair for actually reading my question and give me a helpful answer.

It would be excessively costly to put and external control for a human to dial up any power setting.[/B] That is what a light meter is for. Set two of the three parameters of the exposure triangle and it calculates the third parameter to get a proper exposure.