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Old Jun 22, 2005, 10:50 AM   #1
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We are purchasing our first digitial camera and not that familiar with ISO. I have noticed in other reviews that most use 100 or 200. I had always thought 400 to be the best. If we plan on shooting a lot of outdoor, wildlife , which would be a good choice. Or better yet how do we make the choice?
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Old Jun 22, 2005, 11:18 AM   #2
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This is from Steve's Digicam Dictionary "ISO - The speed or specific light-sensitivity of a camera is rated by ISO numbers such as 100, 400, etc. The higher the number, the more sensitive it is to light. As with film, the higher speeds usually induce more electronic noise so the image gets grainier. ISO is the abbreviation for International Standards Organization. (In the good old days it was known as the "ASA film speed.")"

If you are shooting outside with good light then ISO 100 usually a better choice. If your shooting in low light conditions then a higher ISO may be better. The higher the ISO the more noise you may see in your photos.
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Old Jun 22, 2005, 11:20 AM   #3
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An ISO rating indicates how receptive the media (film or digital) is to light. The higher the ISO rating, the more receptive to light. In practical terms, higher ISO allows for a higher shutter speed, given the same situation.

style="BACKGROUND-COLOR: #000000"For example, if you are shooting at ISO 100 and have a shutter speed of 1/125, an ISO of 200 FOR THE EXACT SAME SHOT will allow a shutter speed of 1/250. An ISO of 400 will allow a shutter speed of 1/500.

style="BACKGROUND-COLOR: #000000"However, this gain in shutter speed comes at a cost. In film, higher ISO means more grain. In digital, higher ISO means more noise. Most non-DSLR digicams have very noticable noise at ISO 200 and significant noise at ISO 400 (if the camera can even reach that high). DSLR cameras have larger sensors and better noise-reduction algorithms so you can shoot at a higher ISO and still get good results. So, if you are buying a non-DSLR I would not expect to shoot at ISO 400 - most of your shots will be in the ISO 50-150 range. This is one of the biggest differences between the two levels of cameras - the DSLRs can produce images at ISO 800 or 1600 with the same level of noise a digicam has at 200.

style="BACKGROUND-COLOR: #000000"What camera were you considering?
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Old Jun 22, 2005, 11:30 AM   #4
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ISO (International Standards Organisation) numbers are a hold-over from the film industry as a relative measure of a film's sensitivity to light. The Higher the ISO, the more sensitive to light.

The number has a direct relationship to exposure calculation since you need to know how sensitive a film is to light to be able to computer the correct shutter speed for a given aperture.

For example: At ISO100 and an aperture of f8 AND on a bright sunny day, you could expect a shutter speed of 1/500th

But at ISO 400 with the same aperture of f8 and the same bright sunny day, your shutter speed will be 1/2000th.

Notice that the ISO is 4x greater in the second instance AND that the resulting shutter speed is 4x FASTER (to compensate for the more sensitive film)

Film camerasare fixed to the ISO of the film that was loaded (You CAN override the setting for the entire roll if you like but can'tchange the setting until the roll is done) but digital cameras have the option of using ISO as another variable in their exposure calculations. In some 'Auto' or 'P' settings, some cameras will alter the ISO of the sensor to bring the image within the camera's exposure range. For example, if your camera CAN'T do a 1/2000th shutter speed...the exposure system can alter the ISO down until you reach a shutter speed that it CAN deliver. (e.g. reducing ISO to 200 would require the shutter to remain open longer...say...only 1/1000th).

Now, for digital cameras, the ISO numbers that are given should not be taken as equivalent to film ISO. there is really no standards agency that makes sure that digital camera ISO 400 is REALLY 400 and really the equivalent of ISO200 or ISO600...it is a general and relative scale for each camera.

Just like film, as ISO increases, 'noise' (or 'grain' in film) also increases and, in some cases, it might result in an objectionable amount of 'graininess' but, that is for the photographer to decide. If it means the difference between getting the shot (and putting up with the noise) or NOT getting the shot at all... I'll take the shot!
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Old Jun 22, 2005, 11:45 AM   #5
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With digitals, the higher you turn up the ISO the more amplification is applied to the sensor output.

I guess you can think of your lowest ISO setting as unity, and anything higher is being amplified including noise from the sensor as well as any noise injected by the amplifier process itself. With the higher ISO settings you also loose some in fine image detail.

The cameras lowest standard ISO setting is where it usually preforms the best for image quality.
If it is a choice of fine detail or getting the shot, up goes the ISO :-)

Peter.
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Old Jun 22, 2005, 11:52 AM   #6
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Hey Meryl, Im from T.O. too!:-)
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Old Jun 22, 2005, 12:19 PM   #7
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Well we aren't going too advanced here. We had a Canon Sureshot. I bought the KodakZ740, but we need zoom for when we travel, (wildlife), and there is not Imaging Stabilzer in Kodak. I would like something with good clear pictures, even when zooming and stong color. I am a little concerned about autofocus. On the Kodak , with auto focus, it seemed to keep getting in and out of focus. I know a lot of this can be changed manually, but I don't know enough about shooting to do so.

Sooooo these are the camera's I've narrowed it down to. ANY SUGGESTIONS WOULD BE WELCOME!

Sony Cyberhsot DCS-H1

Canon Poweshot S1 IS...a little worried about only 3 megapixels

Panasonic Lumix DMC-FZ5....Only problem with this one is I can't seem to relate good photographs with the name "Panasonic"

Konica Minolta DiMage Z5....color does not seem to be as vivid as in the others. I know it is more "natural", but I like the more vibrant colors.
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Old Jun 22, 2005, 12:27 PM   #8
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Have a look at some of the images found in the Panasonic forum :-).
http://www.stevesforums.com/forums/view_forum.php?id=23

Peter

1020 wrote:
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Panasonic Lumix DMC-FZ5....Only problem with this one is I can't seem to relate good photographs with the name "Panasonic"
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Old Jun 22, 2005, 5:55 PM   #9
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Quote:
Panasonic Lumix DMC-FZ5....Only problem with this one is I can't seem to relate good photographs with the name "Panasonic
From this site: http://resellerratings.shopping.com/...Lumix_DMC_FZ20
That camera got five stars! So even though you can relate Panasonic to good photgraphs (I can't either!) I guess it works....


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13 years old with a Canon Digital Rebel (300D for the  slower mind), 28-80mm Canon Lens, and Sigma 70-300mm Lens on the way!
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Old Jun 22, 2005, 7:59 PM   #10
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that is for the FZ20...but I am sure the FZ5 is the same... I have read a lot of good reviews...just can't get used to the name.
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