An In-depth Discussion of M + Auto-ISO Part II

[John Sheehy]

Just as in non-flash M-mode, where I don't change the Av and Tv values. Why would I change them because I decided to use flash?

Apparently, Canon is totally unaware of the value of well-implemented auto-ISO, and think that anyone who uses auto-ISO wants the camera to do all the thinking, which is nonsense. The ultimate purpose of automation is not loss of control, but automating deterministic tasks. Control; not chaos.

--
John

 

[schmegg]

The rear wheel is the Flash Exposure Compensation setting when you've pressed the ISO/FEC button.

Try again

I don't recall the 9-way controller doing anything in shooting mode.

Many (well, me at least ;-) ) use the 'joystick' to select AF points. That's one thing I definitely wouldn't want to give up

 

[aVolanche]

Just as in non-flash M-mode, where I don't change the Av and Tv values. Why would I change them because I decided to use flash?

Apparently, Canon is totally unaware of the value of well-implemented auto-ISO, and think that anyone who uses auto-ISO wants the camera to do all the thinking, which is nonsense. The ultimate purpose of automation is not loss of control, but automating deterministic tasks. Control; not chaos.

--
John

I totally agree! Canon continues to befuddle me with their decisions. The "no EC" in M-mode is particularly irksome, as is the flash default to ISO 400.

Fred

 

[John Sheehy]

The rear wheel is the Flash Exposure Compensation setting when you've pressed the ISO/FEC button.

Try again

I don't recall the 9-way controller doing anything in shooting mode.

Many (well, me at least ;-) ) use the 'joystick' to select AF points. That's one thing I definitely wouldn't want to give up

Don't you have to press a button on the upper right to enable AF point selection?

I don't recall it working without enabling the selection. No conflict, AFAIK.

--
John

 

[ultimitsu]

So for 7d it activates FEC, alright, next question is, is there a need for FEC when using auto iso? I think probably not. Auto iso isn't particularly useful with flash to begin with.

Huh??? Lack of auto-ISO with flash enabled is a huge obstacle for me.

Flash would work perfectly with auto-ISO in M, Av, and Tv modes. ISO would be selected first, based purely on ambient light, and then flash would work as a FEC relative to it. Very simple, and ......

I don't doubt that would be useful once properly implemented, but as is autoiso with flash doesn't quite work like that, it just permanently stuck on iso400, I get a feeling that it cannot be improved by simple firmware change as it may be somewhat limited by the current metering system. So if that is true, then FEC and autoiso would only be useful in the next generation of cameras. By then we don't really need to worry about how to fit it in current 7d button set up.

 

[ultimitsu]

Many (well, me at least ;-) ) use the 'joystick' to select AF points. That's one thing I definitely wouldn't want to give up

Don't you have to press a button on the upper right to enable AF point selection?

Not on 60d, I use it enable af points since day one. I am guessing 7d may offer similar accessibility.

 

[John Sheehy]

I don't doubt that would be useful once properly implemented, but as is autoiso with flash doesn't quite work like that, it just permanently stuck on iso400, I get a feeling that it cannot be improved by simple firmware change as it may be somewhat limited by the current metering system. So if that is true, then FEC and autoiso would only be useful in the next generation of cameras. By then we don't really need to worry about how to fit it in current 7d button set up.

No change in physical controls would be needed. The only reason the ISO gets stuck on 400 is because some hole(s) at Canon say(s) it should be so. It takes extra code to make it do that.

If ISO==auto AND Flash==enabled then ISO=400;

Gee, thanks Canon, you're so considerate to the more astute photographers.

--
John

 

[ultimitsu]

Flash would work perfectly with auto-ISO in M, Av, and Tv modes. ISO would be selected first, based purely on ambient light, and then flash would work as a FEC relative to it. Very simple, and very useful.

can camera meter do that?

what you are asking it to do here is two different metering done at the same time .

1, meter ambience so it works out correct iso that would expose ambience correctly,

2, meter the main subject so it works out correct flash power (subject to EC) that would expose the subject correct.

I am not aware this ability.

to borrow Port Royal Dad 's excellent example, ( http://forums.dpreview.com/forums/readflat.asp?forum=1019&thread=39545854&page=1 )

 

[John Sheehy]

Flash would work perfectly with auto-ISO in M, Av, and Tv modes. ISO would be selected first, based purely on ambient light, and then flash would work as a FEC relative to it. Very simple, and very useful.

can camera meter do that?

How could it not, if it can work with fixed ISO? After the ISO is selected, based on the ambient light, it is then also "fixed".

what you are asking it to do here is two different metering done at the same time .

What are you talking about? Instead of floating Av or Tv based on metering (with fixed ISO), ISO floats based on metering.

1, meter ambience so it works out correct iso that would expose ambience correctly,

2, meter the main subject so it works out correct flash power (subject to EC) that would expose the subject correct.

I am not aware this ability.

I am not aware of the problem that you are imagining.

to borrow Port Royal Dad 's excellent example, ( http://forums.dpreview.com/forums/readflat.asp?forum=1019&thread=39545854&page=1 )

I have no idea what these images are supposed to mean in this context.

--
John

 

[aVolanche]

Flash would work perfectly with auto-ISO in M, Av, and Tv modes. ISO would be selected first, based purely on ambient light, and then flash would work as a FEC relative to it. Very simple, and very useful.

can camera meter do that?

what you are asking it to do here is two different metering done at the same time .

What am I missing here? Looks like you have no understanding at all of the manner in which Canon dslrs treat flash exposures. The examples you gave are not pertinent to this discussion.

1, meter ambience so it works out correct iso that would expose ambience correctly,

2, meter the main subject so it works out correct flash power (subject to EC) that would expose the subject correct.

I am not aware this ability.

to borrow Port Royal Dad 's excellent example,

Fred

 

[ultimitsu]

ok... not sure where the disconnect occurred so lets start over.

if one uses manual flash, auto iso makes compete sense, you meter for ambience light, ambience gets correct exposure, you manually set flash power so your main subject gets correct exposure. see these 3 pictures demonstrating this effect, except there are done by manually seting exposure for ambience and metered for main subject (ETTL)

but if you let camera do both metering for ambience and main subject, there are two seperate metering . I am not sure if it can do it.

 

[aVolanche]

ok... not sure where the disconnect occurred so lets start over.

.
You are acting like someone else is missing the point.....No!

if one uses manual flash, auto iso makes compete sense, you meter for ambience light, ambience gets correct exposure, you manually set flash power so your main subject gets correct exposure. see these 3 pictures demonstrating this effect, except there are done by manually seting exposure for ambience and metered for main subject (ETTL)

This is just wrong. Try this: Put your camera in M-mode and set a shutter speed (say 1/125), then pick an aperture (say f5.6). Take photos indoors at iso 200, then 400, then 800, then 1600. See what happens.

I have no idea why you are saying "you manually set flash power so your main subject.....".

but if you let camera do both metering for ambience and main subject, there are two seperate metering . I am not sure if it can do it.

Fred

 

[ultimitsu]

What am I missing here?

all of it.

Looks like you have no understanding at all of the manner in which Canon dslrs treat flash exposures. The examples you gave are not pertinent to this discussion.

if you dont understand what I am saying, then how can you question my understanding of anything?

in any case I am not asking you a question so you need not worry about not getting it or answering it. move on

 

[ultimitsu]

ok... not sure where the disconnect occurred so lets start over.

if one uses manual flash, auto iso makes compete sense, you meter for ambience light, ambience gets correct exposure, you manually set flash power so your main subject gets correct exposure. see these 3 pictures demonstrating this effect, except there are done by manually seting exposure for ambience and metered for main subject (ETTL)

but if you let camera do both metering for ambience and main subject, there are two seperate metering . I am not sure if it can do it.

in case if that still was not crystal clear. I will add this.

if you use automatic flash with FEC and complete manual control (M + user set ISO) you camera meters for the subject, and produce right amount of flash to correctly expose that. just like the example images I borrowed from Port Royal Dad.

so, what I dont think the camera can do is meter both ambience and the subject seperately, then set correct auto-iso for ambience AND correct flash power for the subject.

 

[John Sheehy]

ok... not sure where the disconnect occurred so lets start over.

if one uses manual flash, auto iso makes compete sense, you meter for ambience light, ambience gets correct exposure, you manually set flash power so your main subject gets correct exposure. see these 3 pictures demonstrating this effect, except there are done by manually seting exposure for ambience and metered for main subject (ETTL)

but if you let camera do both metering for ambience and main subject, there are two seperate metering . I am not sure if it can do it.

in case if that still was not crystal clear. I will add this.

if you use automatic flash with FEC and complete manual control (M + user set ISO) you camera meters for the subject, and produce right amount of flash to correctly expose that. just like the example images I borrowed from Port Royal Dad.

so, what I dont think the camera can do is meter both ambience and the subject seperately, then set correct auto-iso for ambience AND correct flash power for the subject.

I can't put my head into your hypothetical world.

Here is the problem: I shoot with manual exposure and auto-ISO. When I want to use the flash for fill, however, I get garbage - just glare in an otherwise black scene, because ISO 400 is completely useless. I want the camera to choose the ISO based on the ambient light, and the ambient light alone, because I want FILL FLASH; not crappy, worthless direct-flash-only pictures. The camera could do this, very easily, with a change in programming. It sends out the pre-flash to determine

how much flash is needed, and gives the needed amount of flash for fill - where is the problem that you envision?

--
John

 

[Jeff Peterman]

if you let camera do both metering for ambience and main subject, there are two seperate metering . I am not sure if it can do it.

Have you ever read the manual for a Canon DSLR? They've had this feature since at least the 10D. In Av mode, the camera sets the exposure based on the ambient light, varying the shutter speed to get the right exposure. It then triggers the pre-flash and based on the selected ISO and aperture calculates the amount of flash needed to give the correct exposure. It then takes the actual exposure, with the flash at lower power than required if used alone, to create an image combining both ambient light and the flash. There's absolutely no reason why this couldn't work just the same in manual exposure with auto-ISO.
--
Jeff Peterman

Any insults, implied anger, bad grammar and bad spelling, are entirely unintentionalal. Sorry.
http://www.pbase.com/jeffp25
http://www.jeffp25.smugmug.com

 

[aVolanche]

What am I missing here?

all of it.

Hardly! Once again, you have a big problem when the truth smacks you in the mouth. Your vendetta against me, when you are wrong is laughable. You like to call me a clown. Look in the mirror!

Looks like you have no understanding at all of the manner in which Canon dslrs treat flash exposures. The examples you gave are not pertinent to this discussion. Go back and read John Sheehy's and Jeff's replies. As John said, you have dreamed up a uselessly complicated, hypothetical situation when the proper usage is already there, but for one tweak tha Canon refuses to make.

if you dont understand what I am saying, then how can you question my understanding of anything?

I understand exactly what you are saying. It's just not pertinent to this discussion about how Canon dslrs work in M-mode with flash. It's not a complicated concept for anyone else. I have shown you to be wrong countless times (I can list some instances!) and you have a really hard time dealing with it.

In any case, I am not asking you a question so you need not worry about not getting it or answering it. move on

You cannot tell me when to participate in this forum, nor to whom to direct my replies. You are a pitiful, self-absorbed, angry little guy. Have you noticed that nobody is agreeing with you ? The reason is that you are wrong and are not comprehending the subject. Why don't YOU move on ?

 

[ultimitsu]

Here is the problem: I shoot with manual exposure and auto-ISO. When I want to use the flash for fill, however, I get garbage - just glare in an otherwise black scene, because ISO 400 is completely useless. I want the camera to choose the ISO based on the ambient light, and the ambient light alone, because I want FILL FLASH; not crappy, worthless direct-flash-only pictures. The camera could do this, very easily, with a change in programming. It sends out the pre-flash to determine how much flash is needed, and gives the needed amount of flash for fill - where is the problem that you envision?

I just thought about it again. I think it would work.