What does ISO settings do?

by dat1asiandude Mar 14, 2006 9:07AM PST

I really don't know what it means. I got a Canon SD450 and I bumped up the ISO setting all the way to ISO 400 and all it did was made the picture brighter.

Discussion is locked

- Collapse -

ISO settings

by snapshot2 Forum moderator Mar 14, 2006 11:49AM PST

You can consider it a volume control for light.

Raising the ISO setting from 50 to 100, will cause the image sensor to be twice as sensitive to light.
Raise it from 100 to 200 will increase the sensitivity to twice what it was. etc, etc.

This is similar to using higher speed film in film cameras.
But without actually having to change film.
A major convenience.

When you raise the ISO setting you also raise the noise level. Noise will appear in the photo as a grainy appearance in darker areas of the photo.

Here is a link to a write-up on the subject:

http://www.dpreview.com/learn/?/key=sensitivity

...
..
.

- Collapse -

ISO Settings

by taboma Mar 14, 2006 2:22PM PST

Joe, Nice link and really easy to understand. Good examples also.
Now I have to go back to my Canon SD500 and check out the settings making sure my ISO settings are normal at 100.
Good info Joe.
Here is a genuine question. I want to photograph a white Snow Drop flower with a background of snow while during noon with brilliant sunlight. Where should the ISO be set at?
What about general outdoor photography during sun-lit winter snow scenes?

-Kevin

- Collapse -

In my opinion,

by jump1127 Mar 14, 2006 9:53PM PST

snow reflecting causes some flares in the shooting picture. Make sure that you avoid the direct light reflecting, by shooting at the right angle where possible flares can be minimum. Proper light metering is also necessary. You need 2/3 - 1 stop over exposure to make sure the snow is white. Enjoy shooting. Good luck.

- Collapse -

Not Joe, but in bright light you need the ISO as low as it

by Kiddpeat Mar 15, 2006 12:44AM PST

will go. You don't need light amplification at those light levels. Then, do your best to meter on the flower so that it will not be overexposed. If your exposure is proper for the flower, the snow should take care of itself. That's assuming that the flower is not in shadow.

In those conditions, I frequently shade the flower to prevent it's color from being blown out by sunlight.

- Collapse -

Bright light

by taboma Mar 15, 2006 12:07PM PST

Kiddpeat, Did not know you were into flower photography. Nice to know that. Good info from you by the way.
Sometimes I have a card or an umbrella out in the garden while photographing flowers to redirect the full sun off the flower. Burn-out is correct.
My best photography is in the early to mid-morning just when the flower is fully opened. A hazy day produces my best shots. Almost like tenting the subject. Blazing sun at noon time is the worst time of the day for me to photograph flowers.
I have to send you a few daylily photos to share. I am a hybridizer of Hemerocallis. Belong to the American Hemerocallis Society for quite a while.
Thanks,

-Kevin

- Collapse -

Yes, I like to photograph extreme closeups to get all the

by Kiddpeat Mar 15, 2006 2:17PM PST

details. My Nikon 4500 is VERY GOOD at that. It can focus, in macro mode, extremely close to the flower. Many times, it seems like I am less than an inch away. It does frustrate me when it cannot lock the focus on a flower. I can see it go right past the focus point and scan back again trying to lock. Unfortunately, it doesn't seem to have a manual control for this. My 20D does OK, but doesn't seem to produce the same quality of picture. Maybe I'm becoming jaded.

Hazy days are best for all kinds of photography. You get the best colors without blowing out the highlights.

What does ISO settings do?

CNET Forums

Other Forums

Forum Info