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Old May 11, 2007, 10:28 PM   #1
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When i got the D50 i shot in AUTO mode for a few weeks. The camera adjusted the iso automatically, even when shooting with flash popped up. Sometimes the subject was underexposed in back lit situations because the flash didn't pop up. I set it to Program AE(P mode) to adjust sharpness, saturation and to have fully control over the flash. Problem was the ISO value stayed at 200(with or without the use of flash). This caused underexposed pics when using the flash at night. I want the ISO to be in automatic mode(even when using the flash) so i set ISO AUTO to on and i choose (P, A, DVP mode) and 1 sec(lowest shutter speed) for max shutters speed.
Question is, is this the right procedure to have the ISO automatic, and if so will the camera alter the ISO automatically when shutterspeeds increases(above 1 sec)?????
I have to shoot my sister's bithday party next week, so please help me

many thanks in advance

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Old May 12, 2007, 10:06 AM   #2
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The easiest way to tell how your camera is going to behave in a given mode is to test it. I don't have a D50, so perhaps some D50 users will see this thread and give you more insight as to how your model works.

With most cameras, Auto ISO is designed to increase only when shutter speeds are slower than around 1/focal length. For example, if you're shooting zoomed into 50mm, the Auto ISO makes sure that shutter speeds are 1/50 second or faster. Of course, how fast a shutter speed the camera can use will also depend on the aperture selected.

That may not be what you want. As for flash photos, most cameras won't care about increasing ISO speed (or shutter speed) in low light. Many models use a fixed shutter speed and vary the output of the flash for proper exposure.

If you're getting underexposed images, it's probably something you're doing wrong (trying to shoot outside of the rated flash range, focusing on something that is not neutral since most metering systems weight the focus point more, using a metering mode that isn't right for the conditions, shooting a backlit subject where you may need to use Exposure Compensation to prevent underexposure, or other.

If you want the camera to use a higher ISO speed, the easiest way to achive that is to set it that way (just the way you'd change films if you wanted a faster or slower film speed). ;-)

Using a higher ISO speed for any given lighting condition and aperture will give you greater flash range. But, remember that the camera still has to worry about properly exposing your focus point. So, if it properly illuminated a closer subject, further way subjects may be underexposed (because if it tried to properly expose a subject that's further away, the closer subjects would be overexposed). Pay attention to your focus point (as most matrix metering systems will weight it heavily)

A higher ISO speed can help some, because more ambient light will be contributed. But, you still need to be aware of flash distance limitations and more. The built in flash in most cameras is not good for more than around 12 feet or so at lower ISO speeds with a typical consumer lens (and each time you double the ISO speed, flash range will increase by 1.4x).

Of course, noise will also be higher at higher ISO speeds, which is one reason most camera manufacturers are not going to increase ISO speed much using Auto ISO with flash (so that you'll get higher quality images, provided you stay within the rated flash range). If you don't like the way it behaves, set it yourself. ;-)

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Old May 14, 2007, 3:17 PM   #3
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See page 91 of the manual... User sets the ISO in P, S, A or M modes
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