Exposure doubts

[cpc1225]

I am a Canon G2 user and have a question on exposure.
I need to shoot on a subject under a shade with bright background, I wanted the fore ground detail as well as the background.
I set the flash to "on", aimed at the back ground, half press the shutter button and press * to lock the exposure, released the shutter button, aimed at my object and press the shutter button fully to take the shot.
The result shows backgrounds are over exposed.
Where have I done wrong?

[barnold999]

Was the foreground exposed properly...?

What flash? I guess not built in...

shooting with a bright background is a difficult thing to do, when you have something darker in the foreground.

[cpc1225]

Fore ground exposures are acceptable.
It was the built in flash.

[Roger_Cavanagh]

Hard to be certain without seeing an example, but if you took your meter reading from a dark object in the shade that will give settings tending to over-exposure.

Camera meters assume that the subject is a bit darker than mid gray and choose exposure settings to produce that colour in the resulting image. If you meter off a "white" object that will give readings leading to under-exposure: the camera reasons "that's too bright, better reduce exposure so it comes out gray". Conversely, metering from a dark subejct will give the reverse effect. Less light is reflected by the darker colour, so the camera compensates by increasing exposure.

Using the flash will only exacerbate the over-exposure unless you make other adjustments.

This article may be of interest:

http://www.rogercavanagh.com/helpinfo/29_graycard.htm

Regards,

[scottbergerphoto]

Roger_Cavanagh wrote:
Hard to be certain without seeing an example, but if you took your meter reading from a dark object in the shade that will give settings tending to over-exposure.

Camera meters assume that the subject is a bit darker than mid gray and choose exposure settings to produce that colour in the resulting image. If you meter off a "white" object that will give readings leading to under-exposure: the camera reasons "that's too bright, better reduce exposure so it comes out gray". Conversely, metering from a dark subejct will give the reverse effect. Less light is reflected by the darker colour, so the camera compensates by increasing exposure.

Using the flash will only exacerbate the over-exposure unless you make other adjustments.

This article may be of interest:

http://www.rogercavanagh.com/helpinfo/29_graycard.htm

Regards,
Roger,
I just read your link on using a Grey Card. I am a little confused by your recommendations for light and dark objects. You recommend Decreasing exposure on Light objects and Increasing exposure on Dark objects from what a reflected meter says. My understanding of reflected light meters(in camera meters, spot meters) and the Zone System suggests the opposite.
If I am shooting a very light object (snow), I know that my meter sees that as 18% grey. Since I don't want my snow to look grey, I increase exposure by 1-2 stops. Conversely, If I am shooting a black object (men's suit, black bear), my meter will try to make that look grey. To keep the suit/bear looking black, I'm going to underexpose that picture 1-2 stops from what the meter says.
Your suggestions seem more appropriate for adjusting the readings for an incident meter.
Comments?
Scott
Note:
Please see my own response to this below. It's an apples and oranges kind of thing.
Scott

[stoneylonesome]

I agree with Scott, I've always been lead to believe that on a bright object i.e snow you have to fool the camera, because it thinks its getting to much light and tends to underexpose everything else so you go 1 or 2 stops on the + in the Old SLR film days if the cameras meter said it was exposed at say f8 with the bright snowy background you actually set f5.6 or f4 to compensate ( fool the camera) I think I got that right, it's so confusing :D :D

[scottbergerphoto]

I spent about two hours thinking about this, and that Roger Cavanaugh knows his stuff. The fact is, in his LINK, Roger is talking about using the readings off a GREY CARD and adjusting for the actual exposure based on what reflectance the subject is in relation to 18% Grey. His adjustments are to the exposure off an18% Grey card. That is one method of calculating exposure, a very good one. Roger described exactly what he said he was going to describe, using an 18% Grey Card. The first part of Roger's POST however, has to do with a different method, Not involving a Grey Card which I was referring to.

This method of exposure I was referring to and which I use on a regular basis is a modified Zone System. This is based on readings taken off a SUBJECT (not a grey card), and adjusting the exposure based on the subject's difference in Zone from 18% Grey. On a modified 5 Zone System, bright white and black are two zones each away from 18% grey. Light grey and dark grey are one zone each away. So, you decide whatever is the tone you are most interested in in the picture, take a reflected reading off of it, and adjust your exposure up or down based on it's relationship to 18% Grey. The idea is that if one tone in the picture is accurately exposed, then the rest should be as well.

Black(4.5%)--Dark Grey(9%)--18%Grey--LightGrey(36%)--White(72%)

Hence, if you take a reading off of white snow, which is two zones away from 18% Grey, you increase exposure dictated by that reading by about two stops. That should give you white snow. If your taking pictures of a Black Lab, you'll want to decrease the exposure by 1-2 stops from the reading you took off the Black Lab. These are approximations, so you check the histogram and adjust or bracket your exposures. I suggest, "The Confused Photographers Guide to the Zone System", by Farzaad.

Next time I'll wait till after my second cup of coffee before taking on the tecnical questions.
Happy Holidays,
Scott