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Old May 27, 2010, 4:51 PM   #11
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..... a room big enough to house a car is a big room!

What metering mode and focus mode were you using? I guess the camera could work out very different exposures using (1) spot metering and single point focus at 1.5m - e.g. car bonnet - compared to (2) multiple-zone and multi-point at 8-10m - e.g. back of the room.... just a thought.

Did you try shooting in 'A' mode (rather than 'P') and slow-sync flash..?
As you can see from the samples, I was not trying to illuminate the entire room Just the car would be nice!

The metering was Center weight and the focus I only use center single-point. I did not shoot in A mode either but I'm not sure that would have made a difference. However, I think I need to set the camera to ISO 400 (that's what I use on my FZ28 to make sure the flash covers a larger area). The bottom line here is, unless you guys can spot some improper setting that I can't, I think in P mode the camera should have metered properly and provide the correct flash exposure based, if nothing else, on the distance between me and the car, which was only a couple of feet.
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Old May 27, 2010, 4:58 PM   #12
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I might be barking up the wrong tree, but I think having seen the photos that reflections are the main culprit to the exposure problems.... I would guess that the third image is brighter (and closer to 'correct' exposure) because the bodywork hasn't directly reflected the flash back to the camera, as appears to have happened in the other shots. Just a thought
Humm, I dunno. The second image is hardly reflecting any light.
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Old May 27, 2010, 5:34 PM   #13
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The metering was Center weight and the focus I only use center single-point. I did not shoot in A mode either but I'm not sure that would have made a difference. However, I think I need to set the camera to ISO 400 (that's what I use on my FZ28 to make sure the flash covers a larger area)...
Yep... if you want to use the camera's built in flash in those types of conditions, that's probably your best bet (set the ISO speed higher).

When you do that (higher ISO speed setting), the camera can use a shorter flash burst, so that ambient light is contributing more and the flash is contributing less for a given aperture and shutter speed (and the camera was already using a relatively slow shutter speed by default).

Otherwise, the camera is going to limit the flash burst length to prevent overexposing the closer areas, which will result in underexposed areas further away from the camera at lower ISO speed settings.

Of course, the best solution would be to get an external flash and bounce it for more even lighting over a larger area.

If nothing else, get an inexpensive Auto Thyristor type flash to use with it, setting the flash and camera to match for ISO speed and Aperture. Then, the sensor in the flash could measure reflected light during the exposure (eliminating the need for a metering preflash), terminating the flash burst when it sees enough reflected light for the Aperture and ISO Speed set (and you could dial in the amount of ambient light you want to contribute via shutter speed settings).

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Originally Posted by Tullio View Post
Humm, I dunno. The second image is hardly reflecting any light.
It doesn't take much. ;-)

I just took a look at that image using the latest beta version of PhotoME, and the focus point in that image was on the bottom left of the center headlamp, with part of the headlamp within the selected focus area.

A reflective subject like a headlight can easily fool a camera's measurement of the metering preflash in order to insure the selected focus point isn't overexposed.
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Old May 27, 2010, 5:36 PM   #14
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Humm, I dunno. The second image is hardly reflecting any light.
Wel, I'm certainly no expert, but there are strong highlights in the chrome bumper and trim within the part of the frame that the camera will be evaluating (based on center-weighted).... From what I've read before about how the "sophisticated" metering systems in digital camera work, this could well be enough to throw things out.

Sticking with number two, it looks to me that the G1 thinks your taking a photo of the front of the car, and to that end, it hasn't actually made that bad a job of figuring things out? Plus, those highlights will make the metering err on the side of caution, resulting in the image being underexposed a touch.

Having said that, I could be completely wrong!!

I doubt the built-in flash is ideal for this type of subject - bounce would have been good - but I fully appreciate you have to work with what you've got... (hence my crazy macro diffuser/concentrator efforts with my GH1 in my other thread!).

Did you take any photos without flash..? They would have been interesting to compare.
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Old May 27, 2010, 5:43 PM   #15
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Seems I was composing a reply at the same time as JimC... I think I said the same thing, although he put it better

Unless I'm mistaken (?), I think 'A' mode could have made a difference, as it would slow the shutter down to properly expose the background, leaving the flash to expose the subject in the the foreground. You would still have had to watch out for those bright reflective highlights though.
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Old May 27, 2010, 5:49 PM   #16
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Well... the shutter speed was already at 1/30 second.

But, the ISO speed was only ISO 100 in the photo we're discussing. So, a better solution would probably be the one that Tullio noticed (increase the ISO speed). That way, the flash would be contributing less to the overall exposure of the scene. A slower shutter speed would accomplish the same goal. But, if ambient light started making up a greater percentage of the exposure at shutter speeds much slower than 1/30, then you'd have to worry about blur from camera shake, too.

There are pros and cons to any approach. But, for those types of images, using a bounced external flash would probably be the best bet.
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Old May 27, 2010, 8:22 PM   #17
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Thanks to both of you for taking the time and commenting on my photos. One of the things that attracted me to the G1 when I first bought it (as opposed to the EP1, which I ended up purchasing later) was the built-in flash because I really did not want to carry a flash unit along with me. Most of the time, I don't need flash or when I do use it, is as a filler when the subject is back lit.

I'm still not totally convinced that the bounced reflection was throwing the camera off. I'll have to run some tests at home but I think the problem was being caused by the FL. The shots where I was close to the car were really under exposed while the only shot a was further away turned out to be better exposed. I wonder in those conditions if I had pointed the camera far away, half pressed the shutter, locked the exposure and then recompose, press the shutter again to focus on the subject and shoot, if the result would be different. Something else for me to test, I suppose!
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