5D MK 3 and auto ISO

[Tcapp]

BTW, why would anyone shoot hand held with a 1.2 lens in dim light and use a flash?
Feels like washing your feet with your socks on to me?

ET

Really? So you can balance your flash to the ambient light and capture a more natural photo. The flash helps freeze the motion. I do it ALL the time at dark wedding receptions.

+1 Flash give color pop! just use flash as fill even in dim situations.

You and me Bosman, we are on the same page here.

Long live the fast prime!

[sarangiman]

I just noticed:

In M mode, whether the flash is in 'bounce' mode or not, Auto ISO locks ISO at 400.

In A/Tv modes, Auto ISO operates between ISO 100-400.

In P/A+ modes, Auto ISO operates between ISO 100-1600.

Is it just me, or does that seem as nonsensical & inconsistent to you as it does to me?

[Fatalv]

From what I'm reading above I think I'm having issues with my 5DMK3 and 600EX-RT.

When using Av/Tv modes the camera chooses settings without taking into account the flash (flash is set to ETTL mode). At first I wondered why my shots were blurry then looked at the exif data and the shots were taken @ 1/8th

I need to do some more testing but is anyone else experiencing this?

[neuroanatomist]

From what I'm reading above I think I'm having issues with my 5DMK3 and 600EX-RT.

When using Av/Tv modes the camera chooses settings without taking into account the flash (flash is set to ETTL mode). At first I wondered why my shots were blurry then looked at the exif data and the shots were taken @ 1/8th

I need to do some more testing but is anyone else experiencing this?

I think you can stop testing.  There is no 'issue' here, other than user error.  What you state is normal in Av mode - exposure metering ignores the flash because the intent is to expose the ambient (background) properly, then your flash fires a pre-flash which determines the flash power needed to properly illuminate the subject (ETTL).  If you want a faster shutter speed, in the flash control menu you can set the shutter speed in Av mode to 1/200-1/60 s or 1/200 s fixed (instead of the default, which is Auto).  See p. 192 of your manual, or p. 363 where this exact 'problem' is addressed in the troubleshooting guide.  Changing that setting to a faster shutter speed will mean more of the light will be coming from the flash, which means the background will be underexposed, etc.)

Note, you state this occurs in Av/Tv mode - if you're getting 1/8 s exposures in Tv mode without setting that shutter speed yourself (which is the point of Tv mode - you, not the camera, are setting the shutter speed), you do indeed have an issue. 

[Fatalv]

From what I'm reading above I think I'm having issues with my 5DMK3 and 600EX-RT.

When using Av/Tv modes the camera chooses settings without taking into account the flash (flash is set to ETTL mode). At first I wondered why my shots were blurry then looked at the exif data and the shots were taken @ 1/8th

I need to do some more testing but is anyone else experiencing this?

I think you can stop testing.  There is no 'issue' here, other than user error.  What you state is normal in Av mode - exposure metering ignores the flash because the intent is to expose the ambient (background) properly, then your flash fires a pre-flash which determines the flash power needed to properly illuminate the subject (ETTL).  If you want a faster shutter speed, in the flash control menu you can set the shutter speed in Av mode to 1/200-1/60 s or 1/200 s fixed (instead of the default, which is Auto).  See p. 192 of your manual, or p. 363 where this exact 'problem' is addressed in the troubleshooting guide.  Changing that setting to a faster shutter speed will mean more of the light will be coming from the flash, which means the background will be underexposed, etc.)

Note, you state this occurs in Av/Tv mode - if you're getting 1/8 s exposures in Tv mode without setting that shutter speed yourself (which is the point of Tv mode - you, not the camera, are setting the shutter speed), you do indeed have an issue.

Thanks for the info Neuro. It was one of those moments when I needed to grab a shot real quick so I flipped into Av. I usually shoot all Manual but have been experimenting with Av/Tv lately for times like this where I can't preset the shot up. I'll double check the Tv issue when I get home but it's likely more user error on my part

[PhilDrinkwater]

BTW, why would anyone shoot hand held with a 1.2 lens in dim light and use a flash?
Feels like washing your feet with your socks on to me?

ET

Really? So you can balance your flash to the ambient light and capture a more natural photo. The flash helps freeze the motion. I do it ALL the time at dark wedding receptions.

Indeed. I do that at times too. Dim light can be very "dirty" and needs something to clean it up and make it look attractive.

[Hesham]

I tried shooting a 50 F/1.2 @ 1.2 indoors in dim light yesterday and it didn't seem to work as I'd thought.

Were you by chance shooting with the lens cap on?  On in the dark with an exposure of less than 2 minutes?  If so, you might have been experiencing the infamous LCD light leakage issue that people have been up in arms about recently.

This is so rude, the OP asked a ligitimate and interesting question, why make fun of his question. Just because you were scrued by Canon with a defective camera that you cannot return does not mean you can put your anger on other people and unrelated threads. Get a lawyer and go hammer Canon or live with it and don't bother others. the light leak issue has been discussed to death and almost forgotten. get a life  

[bdunbar79]

I have a question to follow up.  This is an issue I've had and there seems to be a better way to fix it than another, and sometimes I get it wrong too.  Suppose I change my metering to spot, and meter on something darker than my object and keep the shutter button halfway depressed to keep the metering.  I know there are other ways, but suppose I chose this.  Then as I move my frame over to focus on my object, would I then have to be in AI Servo mode so that my metering would not change, but the focus would?  Thanks!

[PhilDrinkwater]

I have a question to follow up.  This is an issue I've had and there seems to be a better way to fix it than another, and sometimes I get it wrong too.  Suppose I change my metering to spot, and meter on something darker than my object and keep the shutter button halfway depressed to keep the metering.  I know there are other ways, but suppose I chose this.  Then as I move my frame over to focus on my object, would I then have to be in AI Servo mode so that my metering would not change, but the focus would?  Thanks!

This isn't something I do much, but I suspect it would make more sense to meter, lock exposure and then change to focussing on the point you want.

[bdunbar79]

Gotcha Phil!  Thanks.

[iso79]

Learn to shoot Manual.