Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old May 28, 2004, 10:05 PM   #1
Member
 
Join Date: Oct 2002
Posts: 41
Default

why do they make the iso from 50 to 800 , seems like the only good pics come out under 200 iso or else there is noise in the pic . can someone explain ?
hdshp is offline   Reply With Quote
Sponsored Links
Old May 28, 2004, 10:23 PM   #2
Senior Member
 
BillDrew's Avatar
 
Join Date: Jun 2002
Location: Hay River Township, WI
Posts: 2,512
Default

IMHO, there are two reasons. One is the basic "More/Bigger Is Better" marketing. The other is that those high ISO images can be very good if seriously downsized, e.g., for the web. The downsizing "averages" pixels and thus reduces noise at the same time it reduces resolution.

There is also the question of whether you would rather have a noisy picture of Big Foot or not have a picture at all?
BillDrew is offline   Reply With Quote
Old May 28, 2004, 11:15 PM   #3
Senior Member
 
Join Date: Dec 2002
Posts: 5,803
Default

And as the cameras get better the higher ISOs have less noise. Yes, it costs $4,500USD or so, but the Canon 1D Mark II can be used at around 640ISO and still produce very low noise images.

Eric
eric s is offline   Reply With Quote
Old May 29, 2004, 1:58 AM   #4
Senior Member
 
Mikefellh's Avatar
 
Join Date: May 2004
Location: Toronto, ON, Canada
Posts: 1,707
Default

And there are programs out there designed to clean up the noise at high ISOs.
Mikefellh is offline   Reply With Quote
Old May 29, 2004, 8:53 AM   #5
Member
 
Join Date: Oct 2002
Posts: 41
Default

what does the ISO do ?
hdshp is offline   Reply With Quote
Old May 29, 2004, 10:30 AM   #6
Senior Member
 
Join Date: Dec 2002
Posts: 5,803
Default

Changing the ISO makes the digital sensor more sensitive to light. It allows you to use a higher shutter speed without having to use a flash to get more light.

Eric
eric s is offline   Reply With Quote
Old May 29, 2004, 10:40 AM   #7
Senior Member
 
Join Date: Oct 2002
Posts: 544
Default

In digital cameras, increasing ISO "cranks up" the gain of the sensor. In chemical (film) cameras, higher ISO numbers are associated with grain size.

Higher ISO numbers make the sensor (or film) more sensitive to light, resulting in the ability to use faster shutter speeds and/or operate in lower light situations. The downside of higher ISO numbers is "noise" in pictures with digital cameras (or graininess in chemical cameras).

Point and shoot digital cameras usually produce noisy pictures at ISO numbers aboveabout 400. Digital SLRs do better at ISO values (1600) because of their larger sensors.
Wildman is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 3:05 AM.