someone please explain ISO and exposure

Can someone please explain how adjusting the ISO and Exposure settings
on my digital camera will affect my pictures?

By the way, is ISO the same thing as "shutter speed"? My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

If I'm correct, FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash? It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

Thanks,
A novice photographer

(Martin Lynch) writes:

By the way, is ISO the same thing as "shutter speed"? My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

Take a look at
http://www.kodak.com/global/en/servi.../faq0010.shtml
which has an explanation for ISO as it relates to film. In digital cameras,
the thought is the same.

It is not the same as shutter speed. I shoot with manual cameras a lot, so
from my point of view here's an explanation. If I have a film rated ISO 50,
and my exposure meter says I can shoot at 1/60 of a second at f/16, then I
can vary the shutter speed and aperture and maintain the same amount of
light hitting the film: 1/30 at f/32 or 1/120 at f/8. If my film speed is
ISO 100, I can get the equivalent exposure to ISO 50 with half the
light. So 1/120 at f/16, say, instead of 1/60 at f/16.


If I'm correct, FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

It's a judgment. You may want to use fast shutter speed to freeze action,
but you may also want a slow shutter speed to blur the action, which may
create an artistic representation of speed. Look at
http://www.seriouswheels.com/2005/20...r-1280x960.htm
for an example.

If the light is really low, you may be left with no choice but a wide
aperture and slow shutter speed. You could try setting your digital camera
to a higher ISO to compensate. There may be in increase in noise with ISO
400. Try it and see. Cameras vary in the amount of noise.


As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash? It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

Yeah, you're just confused. The manual which came with your camera will
explain what the -2 to +2 means. It's probably a way of adjusting the
exposure so that it comes out more nearly to what you expect. I would not
use that adjustment to try to get photos in the dark with no flash. Since
you're shooting digital, let me make a suggestion: try all this stuff and
then look at the resulting images on your computer to see how it turns
out.

--
Philip Stripling | email to the replyto address is presumed
Legal Assistance on the Web | spam and read later. email to philip@
http://www.PhilipStripling.com/ | my domain is read daily.

(Martin Lynch) writes:

By the way, is ISO the same thing as "shutter speed"? My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

Take a look at
http://www.kodak.com/global/en/servi.../faq0010.shtml
which has an explanation for ISO as it relates to film. In digital cameras,
the thought is the same.

It is not the same as shutter speed. I shoot with manual cameras a lot, so
from my point of view here's an explanation. If I have a film rated ISO 50,
and my exposure meter says I can shoot at 1/60 of a second at f/16, then I
can vary the shutter speed and aperture and maintain the same amount of
light hitting the film: 1/30 at f/32 or 1/120 at f/8. If my film speed is
ISO 100, I can get the equivalent exposure to ISO 50 with half the
light. So 1/120 at f/16, say, instead of 1/60 at f/16.


If I'm correct, FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

It's a judgment. You may want to use fast shutter speed to freeze action,
but you may also want a slow shutter speed to blur the action, which may
create an artistic representation of speed. Look at
http://www.seriouswheels.com/2005/20...r-1280x960.htm
for an example.

If the light is really low, you may be left with no choice but a wide
aperture and slow shutter speed. You could try setting your digital camera
to a higher ISO to compensate. There may be in increase in noise with ISO
400. Try it and see. Cameras vary in the amount of noise.


As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash? It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

Yeah, you're just confused. The manual which came with your camera will
explain what the -2 to +2 means. It's probably a way of adjusting the
exposure so that it comes out more nearly to what you expect. I would not
use that adjustment to try to get photos in the dark with no flash. Since
you're shooting digital, let me make a suggestion: try all this stuff and
then look at the resulting images on your computer to see how it turns
out.

--
Philip Stripling | email to the replyto address is presumed
Legal Assistance on the Web | spam and read later. email to philip@
http://www.PhilipStripling.com/ | my domain is read daily.

On 9 Oct 2004 19:36:16 -0700, (Martin Lynch) wrote:

Can someone please explain how adjusting the ISO and Exposure settings
on my digital camera will affect my pictures?

By the way, is ISO the same thing as "shutter speed"?

ISO is the SENSITIVITY of the camera. A high ISO can get more light, so it helps
in the dark or with fast exposures of sports, but it increases noise. ISO 400
will give a very 'grainy' picture, no good for quality prints.

My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

it's the most sensitive setting, and the noisiest.


If I'm correct, FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

yes... but you can get blur if you move the camera during the shot.


As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash?

Since you didn't give a qualifier, -2 or +2 doesn't tell me much! It may be the
compensation if the picture is too dark or light. If you think the picture was
too dark, go to plus 1 and shoot again...

It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

'exposure' generally means the combination of all things. High shutter speed and
high ISO can give the same exposure as low ISO and low shutter speed.

'exposure' used to refer to how the film was exposed... long time or short, big
lens or small.

Thanks,
A novice photographer

I'd add a little further note here. IF you push the speed- that is,
set the ISO higher than standard, then yes you would get more noise.
However, if the camera already has a higher ISO value, then you would
not necessarily get more noise.

However, the ISO of a silicon CCD chip is pretty well fixed by the
materials and processes. Most of them are ISO 100. If it is a
different chip technology, on the other hand, then it CAN have a
different ISO. In that case, if it has a higher sensitivity it can
get it without a greater noise. Lets hope the chip manufacturers can
indeed find ways to create faster chips. Hard, as I say, but that is
one area where film is better than digital currently. There are lots
of really great 400 films, and even a few 800 films are pretty good.


Bob wrote in message . ..


ISO is the SENSITIVITY of the camera. A high ISO can get more light, so it helps
in the dark or with fast exposures of sports, but it increases noise. ISO 400
will give a very 'grainy' picture, no good for quality prints.

My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

it's the most sensitive setting, and the noisiest.

On 10 Oct 2004 06:42:05 -0700, (Don Stauffer in
Minneapolis) wrote:

I'd add a little further note here. IF you push the speed- that is,
set the ISO higher than standard, then yes you would get more noise.
However, if the camera already has a higher ISO value, then you would
not necessarily get more noise.

However, the ISO of a silicon CCD chip is pretty well fixed by the
materials and processes. Most of them are ISO 100. If it is a
different chip technology, on the other hand, then it CAN have a
different ISO. In that case, if it has a higher sensitivity it can
get it without a greater noise. Lets hope the chip manufacturers can
indeed find ways to create faster chips. Hard, as I say, but that is
one area where film is better than digital currently. There are lots
of really great 400 films, and even a few 800 films are pretty good.


Noise is related to the actual size of the sensor, so that large (not
pixel-number large but physical-size large) sensors are quieter.

I often shoot with my D70 set to ISO 1000 with no real noise problem. And it
beats any color film I could ever afford!

If sensor technology is anything like solid state technology, it's just a matter
of time before the sensors become quieter. Look at today's transistors compared
to the ones made in the 60s. A stereo back then was quite noisy with a S/N ratio
of barely 50db, now 95db is common. Remember when your stereo hissed when you
turned it up a bit?

Martin Lynch wrote:

Can someone please explain how adjusting the ISO and Exposure settings
on my digital camera will affect my pictures?
ISO is a measure of the film or sensor speed. Old measure was ASA.
Digital cameras can adjust the sensitivity usually from 100 to 400
ISO, with 400 being the higher sensitivity. Higher sensitivity
introduces more noise (artifacts in the picture) so in automatic
systems the camera set to the lower sensitivity if there is enough
light.


By the way, is ISO the same thing as "shutter speed"? My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

If I'm correct, FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

Yes, the only problem with slow shutter speeds is that the subject may
move or the photographer may move the camera and cause blur.

As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash? It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

-2 to +2 refers to stops from the indicated setting or as some cameras
indicate it is a change of sensitivity of the sensor. Basically it
means giving more exposure or less exposure than what the camera
automatically selected. E.g. the camera selects f5.6 and 1/125
second, if you want more exposure then select +1 which will either
open the camera to f4 or slow the speed to 1/60 or it will change the
sensitivity from IS0 100 to ISO 200. +2 is double that of +1 or 4
times 0 setting and -1 is 1/2 of 0 and -2 is 1/4 of 0.


Thanks,
A novice photographer

Greetings Martin,

There are some good pages on the web that will reveal this and help you
understand the reference.

ISO (International Standards Organization) relates to an agreed upon
standard across the industry and world to standards used in the many
processes used in the creation of products. For film or digital, and how
ISO effects you, think of how a given film or CCD reacts to light. For
example, the sunny sixteen rule (an old way of setting your manual camera
for correct exposure) states that if you set the shutter to the ISO and the
aperture of your lens to F/16 you will get a good exposure on a sunny day.
So, if you used Kodak Gold 100 film or set your digital camera to 100, you
would set the shutter to 100 or - if you have an old camera - the closest
setting of say 125 (a digital camera would do this for you). Then set the
aperture to F/16. This would give you a correct exposure on a sunny day.

The F/Stop in a camera is how light is measured. changing one F/Stop either
doubles or halves the exposure of amount of light that is reaching the
film/CCD. Hence going from an F/Stop of F/16 to F/8 increases your exposure
by a factor of two times (doubles). In the reverse, a change from F/8 to
F/16 it halves the amount of light. This also works for the shutter in the
camera. Going from a shutter setting of 1/125th second to 1/250th second
halves the amount of light reaching the film/CCD while going to other
direction it doubles it (1/250th to 1/125th). The slower the shutter the
more light is allowed to reach the film/CCD.

The ISO then relates to how sensitive the film/CCD may be. So, if it is set
to 100 and you go to 200 then the film/CCD will be twice as sensitive.
Knowing this you can control the shutter and aperture of the camera to give
you the exposure you want. The three together allow you a great amount of
control over the light reaching the film/CCD. With digital cameras, this is
done with a computer and sophisticated mechanisms, i.e. electromechanical
aperture shutter combinations. For single lens reflex cameras you often
have manual as well as computer controls and specific shutter and aperture
settings.

The greater the sensitivity of film or CCD, the higher the ISO will be. So,
a 400 speed film is more sensitive. Try the following sites for reviews and
details.

http://www.kodak.com/global/en/consu.../techInfo/af9/

http://www.kodak.com/global/en/consu.../aa9/aa9.shtml

http://www.kodak.com/global/en/consu...c13/ac13.shtml

There are more, and there is publication offered by Kodak that you will have
to call about. But if you search the web you will find much more on this
subject.

Talk to you soon,

Ron Baird
Eastman Kodak Company

"Martin Lynch" wrote in message
om...
Can someone please explain how adjusting the ISO and Exposure settings
on my digital camera will affect my pictures?

By the way, is ISO the same thing as "shutter speed"? My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

If I'm correct, a FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash? It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

Thanks,
A novice photographer

Greetings Martin,

There are some good pages on the web that will reveal this and help you
understand the reference.

ISO (International Standards Organization) relates to an agreed upon
standard across the industry and world to standards used in the many
processes used in the creation of products. For film or digital, and how
ISO effects you, think of how a given film or CCD reacts to light. For
example, the sunny sixteen rule (an old way of setting your manual camera
for correct exposure) states that if you set the shutter to the ISO and the
aperture of your lens to F/16 you will get a good exposure on a sunny day.
So, if you used Kodak Gold 100 film or set your digital camera to 100, you
would set the shutter to 100 or - if you have an old camera - the closest
setting of say 125 (a digital camera would do this for you). Then set the
aperture to F/16. This would give you a correct exposure on a sunny day.

The F/Stop in a camera is how light is measured. changing one F/Stop either
doubles or halves the exposure of amount of light that is reaching the
film/CCD. Hence going from an F/Stop of F/16 to F/8 increases your exposure
by a factor of two times (doubles). In the reverse, a change from F/8 to
F/16 it halves the amount of light. This also works for the shutter in the
camera. Going from a shutter setting of 1/125th second to 1/250th second
halves the amount of light reaching the film/CCD while going to other
direction it doubles it (1/250th to 1/125th). The slower the shutter the
more light is allowed to reach the film/CCD.

The ISO then relates to how sensitive the film/CCD may be. So, if it is set
to 100 and you go to 200 then the film/CCD will be twice as sensitive.
Knowing this you can control the shutter and aperture of the camera to give
you the exposure you want. The three together allow you a great amount of
control over the light reaching the film/CCD. With digital cameras, this is
done with a computer and sophisticated mechanisms, i.e. electromechanical
aperture shutter combinations. For single lens reflex cameras you often
have manual as well as computer controls and specific shutter and aperture
settings.

The greater the sensitivity of film or CCD, the higher the ISO will be. So,
a 400 speed film is more sensitive. Try the following sites for reviews and
details.

http://www.kodak.com/global/en/consu.../techInfo/af9/

http://www.kodak.com/global/en/consu.../aa9/aa9.shtml

http://www.kodak.com/global/en/consu...c13/ac13.shtml

There are more, and there is publication offered by Kodak that you will have
to call about. But if you search the web you will find much more on this
subject.

Talk to you soon,

Ron Baird
Eastman Kodak Company

"Martin Lynch" wrote in message
om...
Can someone please explain how adjusting the ISO and Exposure settings
on my digital camera will affect my pictures?

By the way, is ISO the same thing as "shutter speed"? My camera's ISO
ranges from, I think 100 to 400. Is 400 considered the "fast" speed?

If I'm correct, a FAST shutter speed is used for action shots. But
would you also say that SLOW shutter speed could be used to compensate
for poor lighting?

As for exposure, my camera ranges from -2 to +2. Which setting is for
taking pictures in the dark with no flash? It seems to me that
"exposure" would be synonymous with "shutter speed/ISO" but maybe I'm
just confused.

Thanks,
A novice photographer