ISO vs shutter speed

Archived from groups: rec.photo.digital (More info?)

Just a quick question. I'm getting into photography for the first time
and am enjoying using all the manual options on my new Casio Exilim
P600 (http://world.casio.com/exilim/en/ex_p600/).

I avoid using flash wherever possible and am eager to get the most of
the 'light gathering' possibilities of slow shutter speed and good ISO
settings. My question is this. When I've got OK light and no real
problems with movement (of camera or object), is it usually better to
set a fairly low ISO (100 or such-like) and use a good slow shutter
speed. Will this be the best way to achieve the nice boldness and
contrast that I tend to like in pictures?

I've had some nice result by doing this (and even by narrowing the
aperture and using slower shutter speeds), however I've been confused
by various messages on these newsgroups which claim the opposite - that
high ISO settings and very fast shutter speeds are most desirable.

Thanks for any views.

Mike

Archived from groups: rec.photo.digital (More info?)

"Randy Berbaum" <rberbaum@bluestem.prairienet.org> wrote in message
news7ml5b$6p1$1@wildfire.prairienet.org...
> Rigol <rigolgm@hotmail.com> wrote:
> : Just a quick question. I'm getting into photography for the first time
> : and am enjoying using all the manual options on my new Casio Exilim
> : P600 (http://world.casio.com/exilim/en/ex_p600/).
>
> : I avoid using flash wherever possible and am eager to get the most of
> : the 'light gathering' possibilities of slow shutter speed and good ISO
> : settings. My question is this. When I've got OK light and no real
> : problems with movement (of camera or object), is it usually better to
> : set a fairly low ISO (100 or such-like) and use a good slow shutter
> : speed. Will this be the best way to achieve the nice boldness and
> : contrast that I tend to like in pictures?
>
> : I've had some nice result by doing this (and even by narrowing the
> : aperture and using slower shutter speeds), however I've been confused
> : by various messages on these newsgroups which claim the opposite - that
> : high ISO settings and very fast shutter speeds are most desirable.
>
> : Thanks for any views.
>
> Slower shutter speeds have several problems. One is camera shake. Another
> is mottling due to long exposure. But the mottling is not normally
> discernable until you get well beyond the camera shake limit. But to
> shorten the shutter speed we either have to open the aperture (reducing
> depth of field) or increasing ISO (increasing high ISO mottling). So it is
> all a trade off. If you can handle a slightly longer exposure with a
> smaller aperture (larger f stop number) and/or a smaller ISO number, that
> is fine. I guess that the best way to know how far to push the trade offs
> is to play with your camera until you get a feel for what your personal
> limits are in various situations. For example how long an exposure can you
> take without blurring when unsupported hand held. With a wall to lean
> against. With a wall to set the camera on. And what effects different lens
> sizes (weight and physical dimensions) have on your personal limits.
>
> Randy
>
> ==========
> Randy Berbaum
> Champaign, IL

A good rule of thumb is to use the same shutter speed or higher than the
focal length you are shooting at. So, if you are shooting at 50mm you would
use a shutter speed of 1/50th or faster. At 200mm you would shoot at
1/200th or higher. Now, that's for handheld shots. Some people can
handhold a camera at very slow shutter speeds. As the poster here says,
when you can backup to a wall or use something else to stabilize yourself
you can often drop quite a bit lower. Just experiment as much as you can
since the film is free. Generally speaking, the higher the ISO the more
"noise" you will get, but it also depends a lot on the aperture, total
light, and how your camera interprets noise. I don't find noise in well lit
scenes all that objectionable. Looks like grain in film on my camera. Not
a terrible tradeoff for sharp handheld photos.