|
![]() |
|
LinkBack | Thread Tools | Search this Thread |
![]() |
#1 |
Senior Member
Join Date: Jan 2004
Location: Juneau, Alaska
Posts: 474
|
![]()
I have a Canon rebel XT. I would like to know the higher the ISO the more light allowed in? True or not. I do know the higher the iso more grainy photos are. [img]/forums/images/emoticons/confused-smiley-017.gif[/img]
|
![]() |
![]() |
Sponsored Links |
|
![]() |
#2 | |
Senior Member
Join Date: Jan 2004
Posts: 824
|
![]()
Imacer wrote:
Quote:
Back in film days, high-ISO films used emulsions with larger silver halide grains. The larger grains meant that the emulsion could react more readily to lower levels of light, producing an image under darker conditions but, again, at the expense of the "grainier" appearance of the picture. |
|
![]() |
![]() |
![]() |
#3 |
Senior Member
Join Date: Jan 2004
Location: Juneau, Alaska
Posts: 474
|
![]()
Norm tonight I was taken some phot shots and I was using 100 ISO came out dark, than I switch the iso to 400 my photos came out brighter. I was in P mode.
|
![]() |
![]() |
![]() |
#4 |
Senior Member
Join Date: Dec 2004
Location: Taylor Mill, Kentucky
Posts: 2,398
|
![]()
As Norm mentioned, ISO does not refer to how much light the camera "lets in". ISO refers to sensitivity to light. Higher ISO's require shorter shutter speeds (and/or smaller aperatures) to get the proper exposure. Higher ISO's allow you to capture an image in lower light or freeze action better (at the expense of higher noise levels). I would recommend getting a book on the basics of photography. THis way you could learn how things like ISO, aperature, and shutter speed affect your image. Even though you have an entry level DSLR, there is a lot you need to know in order to use it effectively. Getting a handle on the basics will allow for more enjoyment and less frustration.
While your at the learning stage, I would also recommend learning about post processing. DSLR's produce superior images, but rarely are those images superior out of camera. Good luck!!! |
![]() |
![]() |
![]() |
#5 |
Moderator
Join Date: Aug 2004
Posts: 8,529
|
![]()
Imacer,
Shutter Speed, Aperture and ISO all work together to determine exposure. Aperture controls how MUCH light get's in Shutter SPeed controls how LONG the light gets in ISO controls how sensitive the sensor is to that light from a purely EXPOSURE standpoint, you can adjust any one of the above 3 and get the same exposure. The following settings would all produce the same exposure: ISO 100, Aperture f4.0, shutter speed 1/500 ISO 200, Aperture f5.6, shutter speed 1/500 ISO 100, Aperture f2.8, shutter speed 1/1000 So, in a low light situation you can either increase ISO, increase aperture (smaller f-stop) or decrease shutter speed to obtain a 'lighter' exposure. The trick is understanding what increasing / decreasing each of those elements will do to the photograph. High ISO as you mentioned adds noise or grain. Increasing aperture reduces the depth of field (DOF) which reduces how far in front / behind your focus point objects will be in focus. Reduced shutter speed means less ability to freeze action and more possibility of camera shake entering the picture. The trick is in determining for a specific photograph which of the 3 to adjust based usually on the DOF / shutter speed trade-off. With noise reduction software, high ISOs on your camera are still very usable. That's the extremely high level view. I think the suggestion about getting a book is excellent - then practice adjusting all 3 to see how it affects different types of photographs. |
![]() |
![]() |
![]() |
#6 |
Senior Member
Join Date: Jun 2005
Posts: 377
|
![]()
In the "weekly challenge" forums there is a section on reading material. There are a lot of links to sites you can check out.
The best of the lot are (my opinion): http://www.morguefile.com/archive/classroom.php http://luminous-landscape.com/ http://www.all-things-photography.com/ |
![]() |
![]() |
![]() |
Thread Tools | Search this Thread |
|
|