2/3's rule for 580EX

[OceanRider]

I read somewhere that -2/3 for fill and +2/3 for interiors is a nice "rule" with the 580 EX. I am not pleased with mine so far. Its either too dark or too blown out on 0 setting. Anyone have good luck with this "rule"?

I have been told that Av and Tv the camera auto sets for fill, is this the best mode for say shooting a wedding. But why would I have to do do FEC in these modes.

Just when I got some things figured out, I break the flash outa the box!

Joel

[PacAce]

Think of it this way. At a wedding, when you are taking a picture of the bride in her white gown, does the exposure come out the way you want when you set the EC to 0? Or do you need to use a little positive EC to get the gown to come out white? Attaching a flash doesn't change anything as far as how the camera interprets tones so you would still have to do the same thing, using FEC.

And the same goes for the groom in his black tux.

[OceanRider]

but is'nt that why we have our exposure control ? Like if the dress is white, the camera wants to tone it down, hence over expose by say a stop.....likewise, if its black, it will want to make to make it brighter, so I would go down a stop....why cant the flash just be flash and let me worry bout the rest....it seems now I have to contol not only the over/under exposure but the FEC of the bloody flash too (with every shot this is a real pain and time consumer....

[PacAce]

but is'nt that why we have our exposure control ? Like if the dress is white, the camera wants to tone it down, hence over expose by say a stop.....likewise, if its black, it will want to make to make it brighter, so I would go down a stop....why cant the flash just be flash and let me worry bout the rest....it seems now I have to contol not only the over/under exposure but the FEC of the bloody flash too (with every shot this is a real pain and time consumer....
Maybe I'm misunderstanding your question or problem but that's exactly what I was trying to say. Not only do you have to control your exposure for ambient light but you also have to do the same for the flash. The flash IS being a flash so you have to compensate by using FEC the same way you compensate when you shoot without a flash.

BTW, just in case the confusion is over the exposure control of the camera, EC is only effective for control ambient light but not flash output. And, likewise, FEC is only effective for controlling flash output and has no effect on ambient lighting.

[OceanRider]

ahhhh totally get ya now, well done! Cheers friend. So without flash, you use EC and with you use FEC, nice that makes much more sense. Would it be safe to say that if say...in a church, I get the right FEC which I like, it should be good to go for most shots in the church? Also can I reall y trust my histogram? If its in the middle did I get the right exposure? Left too dark, too right blown out?

Thanks agian

joel

[tim]

Here's a situation: you're shooting a bride dressed in white using a flash, you only have one shot so the histogram is useless. You're outside and the light's dim, but you want to get some of the background. What i'd probably do is leave the EC set at 0 because it controls the exposure for the background. I'd set the FEC to +1 or so, maybe a little more, to compensate for the white dress. Does this sound correct?

Next, add the groom dressed in black into the mix. How would you change the settings then? My gut feeling is to reduce the FEC down to +1 or so.

[robertwgross]

Next, add the groom dressed in black into the mix. How would you change the settings then?

Expose for the bride. The bride and her gown are about five times more important than the groom and his tux, as far as the photograph goes.

---Bob Gross---

[PacAce]

Would it be safe to say that if say...in a church, I get the right FEC which I like, it should be good to go for most shots in the church?
Yes, as long as you are shooting the same subject or other subjects of the same tonality. In other words, if you set the FEC for the bride and continue taking pictures of the bride, then you won't need to change the FEC. However, if after setting the FEC for the bride, you then turn around and try to take a picture of the groom, he'll get way over-exposed, assuming he's in the traditional black tux. So, you always have to be mindful of theoverall tonal reflectivity of your subject and what kind of exposure compensation you are going to need for it.

Also can I reall y trust my histogram? If its in the middle did I get the right exposure? Left too dark, too right blown out?
That's a good question and again, the answer depends on the overall tonality of the subject. The histogram of a bride in a shiny white gown is going to be have data very close to the right side of the graph whereas the one for the groom is going to be leaning towards the left side. If your subject has a medium gray tone, then the bulk of the histogram data is going to fall somewhere in the middle of the graph. If you are going to be using the histogram to check for blown out areas, then you should also be taking a look at the image on the LCD to see what parts of the image, if any, are blinking. If it's part of the subject, then an adjustment in expsure will probably be called for. However, if it's an insignificant part of the background and the subject itself looks exposed OK, then you can probably ignore the blown hightlights.

[tim]

Expose for the bride. The bride and her gown are about five times more important than the groom and his tux, as far as the photograph goes.

What about the first part of the question?

[PacAce]

Here's a situation: you're shooting a bride dressed in white using a flash, you only have one shot so the histogram is useless. You're outside and the light's dim, but you want to get some of the background. What i'd probably do is leave the EC set at 0 because it controls the exposure for the background. I'd set the FEC to +1 or so, maybe a little more, to compensate for the white dress. Does this sound correct?

What I highlighted above isn't exactly a true statement. EC controls the exposure for any ambient lighting, not just the background. If the bride is also illuminated with the ambient lighting or worse, with a stronger nearby light, then the camera will most likely set the ambient exposure settings for her and not the background.

[tim]

What I highlighted above isn't exactly a true statement. EC controls the exposure for any ambient lighting, not just the background. If the bride is also illuminated with the ambient lighting or worse, with a stronger nearby light, then the camera will most likely set the ambient exposure settings for her and not the background.

Yeah I understand that the camera meters for ambient light not the background, I was making the assumption that the amount of light on the bride was small. That does raise another question - does the camera compensate for the ambient light when it decided how much power to put into the flash?

Do my settings sound reasonable? Set the EC to zero and the FEC to around +1/+1.5?

[OceanRider]

Yeah I understand that the camera meters for ambient light not the background, I was making the assumption that the amount of light on the bride was small. That does raise another question - does the camera compensate for the ambient light when it decided how much power to put into the flash?

Do my settings sound reasonable? Set the EC to zero and the FEC to around +1/+1.5?

This sounds aloot like the original 2/3's rule depending on where u are. Man who knew there was sooooo much to learn and remeber in photography!

Thanks all

[PacAce]

Yeah I understand that the camera meters for ambient light not the background, I was making the assumption that the amount of light on the bride was small. That does raise another question - does the camera compensate for the ambient light when it decided how much power to put into the flash?

Do my settings sound reasonable? Set the EC to zero and the FEC to around +1/+1.5?
I'm assuming we are talking about using the Av mode, right? I know that the camera takes the ambient light reading and compares that to the pre-flash reading when determing the flash exposure setting to use. So, the camera probably does compensate for the ambient light in so much as if the ambient light is very strong, then less flash power would be required to expose the subject and, conversely, if the ambient light is very week, then more flash power would be required.

Regarding the EC=0/FEC=+1/+1.5, I would say that that would be reasonable starting point for shooting a bride. To be honest with you, I'm either using M or P mode for flash photography so I never really worry about EC (EC is always 0). I just concentrate on getting the FEC right. I hardly ever use Av for flash photography.

[tim]

That's a good point - I use M for flash photography, so exposure compensation is irrelevant, I should have picked up on that before, doh! I don't really see any difference between P and Av for this kind of thing, i'd probably stick to M even if I wanted to expose the background, i'd just take an educated guess at the exposure length, helped by the meter suggestions.

I don't think the flash would even have to compensate for ambient light - since it measures the reflected light from the subject it won't be able to tell between its flash and ambient, it just meters for what it finds.

I'm not really on the ball today.

[robertwgross]

What about the first part of the question?

Too many variables to answer.

---Bob Gross---